A method for detecting aldehyde ketone compounds in air

Abstract

The present application belongs to the field of environmental air quality detection, and particularly relates to a method for detecting aldehyde and ketone compounds in air. The method comprises collecting blank sample gas and sample gas of a to-be-detected sample after pretreatment and balance treatment by using a DNPH sampling tube to obtain blank tubes and sample tubes, then eluting the tubes with acetonitrile, and obtaining blank liquid and sample liquid after constant volume. Standard working solutions with different concentrations are prepared and analyzed by using a high performance liquid chromatograph, and a diode array detector is used for detection to draw a standard working curve. The blank liquid and the sample liquid are analyzed by using the high performance liquid chromatograph, the difference between the peak areas of target substances in the two liquids is calculated, and the actual content of 26 kinds of aldehyde and ketone compounds in the to-be-detected sample after deducting the background blank is obtained by combining the corresponding standard working curve and calculation formula. The present application realizes complete and effective separation of 26 kinds of aldehyde and ketone compounds at the same time for the first time, and can complete quantitative analysis of 26 kinds of aldehyde and ketone compounds at the same time in one analysis.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of environmental air quality detection, especially relates to the field of in-vehicle air quality detection, and in particular relates to a detection method of aldehyde ketone compounds in air. BACKGROUND

[0002] Aldehyde ketone compounds are one of the main pollutants in indoor air, and most of them have irritant and toxic properties, can cause respiratory infections, and have risks of sensitization, carcinogenesis and mutagenesis. During the production and manufacturing process of automotive interior parts, a large amount of plastics, textiles, leather, rubber, foaming, ink and paint are used as raw materials. These raw materials often use raw materials containing aldehyde ketone compounds or produce aldehyde ketone by-products due to production process during the production process. After the finished parts are installed in the vehicle, these residues will gradually release over time, affecting the air quality in the vehicle. Therefore, aldehyde ketone compounds have been one of the main control projects in the control of in-vehicle air quality by domestic and foreign automobile manufacturers and parts suppliers.

[0003] HPLC is the most commonly used method for the detection of aldehyde and ketone compounds in the field of indoor air and environmental air due to its low detection limit, high sensitivity, good accuracy, easy operation, and low analysis cost. The relevant standards such as international standard ISO 16000-3, environmental standard HJ 683-2014, and automotive industry standard HJ / T 400-2007 all specify HPLC as the detection method, and recommend the method to be applicable to the analysis of 3-14 common aldehyde and ketone compounds. However, there are more than 14 common aldehyde and ketone pollutants in the air, and the common aldehyde and ketone pollutants encountered in daily detection can reach 26. With the increase in the number of target analytes, there are several groups of common aldehyde and ketone compounds that are difficult to separate simultaneously, such as propenal, acetone, and furfural, 2-butanone, n-butyraldehyde, and cyclopentanone, cyclohexanone, isopentanal, pentanal, and glutaraldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, and p-methylbenzaldehyde. If the HPLC analysis method cannot achieve complete and effective separation of the target compounds, the purpose of accurate quantification cannot be achieved. Among the multiple groups of difficult-to-separate components, cyclopentanone (CAS.No: 120-92-3) is a common ketone compound with volatility and special odor, commonly used in the fields of high polymer materials, pharmaceuticals, chemicals, and electronic appliances. Due to its relatively low toxicity, there is no relevant exposure or occupational safety limit at present, so it is often used as an environmentally friendly solvent in the production of various high polymer materials, and is a common volatile residue. There is no relevant detection method reported. However, due to the special odor of cyclopentanone, it has irritant and sensitizing properties, and the residue has a certain impact on indoor air quality, especially indoor odor, so it is necessary to accurately quantify and analyze it. When using the existing HPLC method for detection and analysis, due to the similar properties of cyclopentanone, 2-butanone, and n-butyraldehyde, they often flow out together, which affects the accuracy of the detection results. At present, there is no HPLC method that can simultaneously and effectively separate and quantify 26 kinds of aldehyde and ketone compounds, which greatly limits the application of HPLC in the field of analysis of multiple types of aldehyde and ketone compounds, and is a problem that has not been solved in the field of air quality detection for a long time.

[0004] In addition to high performance liquid chromatography, the detection of aldehyde ketone compounds in the field of air quality detection also includes high performance liquid chromatography-mass spectrometry, gas chromatography and gas chromatography-mass spectrometry. Due to the thermal stability problem of aldehyde ketone compounds and their derivatives, gas chromatography and gas chromatography-mass spectrometry are less used; and the existing high performance liquid chromatography-mass spectrometry has high analysis cost and maintenance cost, and the analysis method is relatively complex, which is not suitable for large-scale industrial application and rapid screening of a large number of samples. Therefore, it has important practical significance to develop a high performance liquid chromatography analysis method which can simultaneously analyze as many aldehyde ketone compounds in the air as possible. SUMMARY

[0005] In view of the above problems of the prior art, the present application provides a method for detecting aldehyde ketone compounds in air, which expands the number of aldehyde ketone compounds detected and analyzed simultaneously by high performance liquid chromatography, solves the problem that high performance liquid chromatography cannot simultaneously separate and accurately quantify 26 common aldehyde ketone compounds in the field of air quality detection, affects the accuracy and detection efficiency of actual detection results, and limits the application of high performance liquid chromatography in the field of analysis of various aldehyde ketone compounds.

[0006] To solve the above problems, the present application provides a method for detecting aldehyde ketone compounds in air, comprising the following steps:

[0007] S1. providing a sample to be tested, and placing the sample to be tested after pretreatment;

[0008] S2. collecting a background blank sample before starting the test or collecting a blank sample synchronously with the sample, collecting the blank sample of aldehyde ketone compounds using a sampling tube coated with 2,4-dinitrophenylhydrazine to obtain a blank tube;

[0009] S3. collecting the sample gas of aldehyde ketone compounds using a sampling tube coated with 2,4-dinitrophenylhydrazine after balancing the pretreated sample to be tested, to obtain a sample tube;

[0010] S4. eluting the blank tube and the sample tube with acetonitrile respectively, and obtaining a blank solution and a sample solution after constant volume;

[0011] S5. preparing 26 kinds of aldehyde ketone-DNPH derivative mixed standard working solutions with different concentrations and analyzing them using a high performance liquid chromatograph, and detecting them using a diode array detector, drawing a standard working curve, and obtaining the regression equation corresponding to each target;

[0012] The aldehyde ketone compounds are as follows:

[0013] Formaldehyde, acetaldehyde, furfural, propenal, acetone, propionaldehyde, butenal, methacrolein, 2-butanone, n-butyraldehyde, cyclopentanone, benzaldehyde, isovaleraldehyde, glutaraldehyde, cyclohexanone, pentanal, o-tolualdehyde, m-tolualdehyde, p-tolualdehyde, 4-methyl-2-pentanone, hexanal, 2,5-dimethylbenzaldehyde, heptanal, octanal, nonanal, decanal;

[0014] S6. The blank solution and the sample solution are analyzed using a high performance liquid chromatograph, and a diode array detector is used for detection, to obtain the peak areas of the target substances in the blank solution and the sample solution. The peak areas of the target substances in the sample solution are subtracted from the peak areas of the target substances in the blank solution, and are respectively substituted into the corresponding standard curve regression equation to calculate the actual content of the 26 kinds of aldehyde and ketone compounds in the sample tube after deducting the background blank. Then, the content of the 26 kinds of aldehyde and ketone compounds in the sample to be measured is obtained through formula conversion;

[0015] The analysis conditions of the high performance liquid chromatography analysis method are as follows:

[0016] Chromatographic column:

[0017] The first chromatographic column is a CNW Athena type C18 chromatographic column, 4.6 mm x 250 mm, 5 µm,

[0018] The second chromatographic column is a GL Sciences ODS-P type C18 chromatographic column, 4.6 mm x 250 mm, 5 µm,

[0019] The first chromatographic column and the second chromatographic column are connected in sequence;

[0020] Mobile phase: A phase is water, and B phase is acetonitrile;

[0021] Injection volume: 12 µL;

[0022] Flow rate: 1.0 mL / min;

[0023] Column temperature: 30-40 °C;

[0024] Diode array detector, detection wavelength is 367 nm;

[0025] The gradient elution program is as follows:

[0026] 0 min, the proportion of mobile phase A is 40%, and the proportion of mobile phase B is 60%;

[0027] 25 min, the proportion of mobile phase A is 35%, and the proportion of mobile phase B is 65%;

[0028] 30 min, the proportion of mobile phase A is 0%, and the proportion of mobile phase B is 100%;

[0029] 40 min, the proportion of mobile phase A is 0%, and the proportion of mobile phase B is 100%;

[0030] 45 min, the proportion of mobile phase A is 40%, and the proportion of mobile phase B is 60%.

[0031] Optionally, the pre-treatment placement temperature is a constant temperature of 20-25°C, the relative humidity is a constant humidity of 40-60%, and the pre-treatment placement time is 6 hours-7 days.

[0032] Optionally, the equilibration treatment adopts a 1 cubic meter test chamber sampling method, and the 1 cubic meter test chamber sampling method collects a background blank sample before starting the test.

[0033] Alternatively, the equilibration treatment adopts a sampling bag sampling method, and the sampling bag sampling method takes a blank bag for parallel testing and synchronously collects a blank sample with the sample.

[0034] Alternatively, the equilibration treatment adopts a whole vehicle sampling method, and the whole vehicle sampling method synchronously collects a blank sample with the sample.

[0035] Optionally, the equilibration treatment temperature of the 1 cubic meter test chamber sampling method and the sampling bag sampling method is 60-65°C, and the equilibration treatment temperature of the whole vehicle sampling method is 23.0-25.0°C.

[0036] Optionally, the elution and constant volume include the following steps:

[0037] The blank tube and the sample tube are eluted in the reverse direction of the sampling direction using acetonitrile, the eluted eluent is collected with a volumetric flask, and the blank liquid and the sample liquid are obtained by constant volume with acetonitrile.

[0038] Optionally, the speed of eluting the blank tube and the sample tube in the reverse direction of the sampling direction in the elution step is 2-3 mL / min.

[0039] Optionally, the 26 kinds of aldehyde ketone-DNPH derivative mixed standard working solution is prepared from a cyclopentanone-DNPH standard stock solution and a 25-kind aldehyde ketone-DNPH derivative compound mixed standard.

[0040] Optionally, the cyclopentanone-DNPH standard stock solution includes the following preparation steps:

[0041] Prepare a hydrochloric acid buffer solution;

[0042] Weigh 2,4-dinitrophenylhydrazine in a volumetric flask, add acetonitrile, and ultrasonically oscillate to dissolve;

[0043] Add the hydrochloric acid buffer solution to the above solution and mix evenly;

[0044] The cyclopentanone is weighed and added to the above solution to perform the derivatization reaction, the molar ratio of 2,4-dinitrophenylhydrazine to cyclopentanone is greater than 2:1, and after being diluted with acetonitrile, the reaction is shaken at 25-45℃ water bath for 10-50 minutes.

[0045] Optionally, during the derivatization reaction of the cyclopentanone-DNPH standard stock solution, the concentration of the hydrochloric acid buffer solution is 1-2 mol / L.

[0046] Optionally, the concentration of the 26 kinds of aldehyde ketone-DNPH derivative mixed standard working solution is 0.006 μg / mL-6 μg / mL.

[0047] Optionally, according to the actual content of 26 kinds of aldehyde ketone compounds in the sample tube calculated by the standard curve regression equation after deducting the background blank, the actual content of 26 kinds of aldehyde ketone compounds in the sample to be tested is calculated according to the following formula:

[0048]

[0049] In the formula:

[0050] G The volatile amount of the sample to be tested, unit: μg / m 3 ;

[0051] W The content of the compounds captured by the sample tube calculated by the standard curve regression equation after deducting the background blank, unit: μg / mL;

[0052] e The constant volume of the acetonitrile eluent, mL;

[0053] Q The amount of gas collected in the sample tube converted at 23℃, 101.3 KPa, unit: L, and the specific conversion formula is as follows:

[0054]

[0055] Wherein:

[0056] V The actual sampling volume, unit: L;

[0057] T The absolute temperature of the sampling point during sampling, unit: K;

[0058] T x The absolute temperature under the reference state, 296.15 K;

[0059] P- the atmospheric pressure at the sampling point at the time of sampling, in kPa;

[0060] P x - the atmospheric pressure in the reference state, 101.3 kPa.

[0061] The beneficial effects of the present application are that: compared with the prior art, the detection method of aldehyde ketone compounds in the air developed by the present application uses high performance liquid chromatography as an analysis instrument equipped with a diode array detector (DAD), through the development of a specific chromatographic column system, the selection of a mobile phase system and the development of a specific gradient elution program, the three interact, influence and cooperate, overcome the shortcomings of each technical feature when applied alone, combined with the development of other analysis parameters, the simultaneous complete effective separation of 26 kinds of aldehyde ketone compounds in the air is successfully realized, the simultaneous separation and quantification problem of several groups of aldehyde ketone compounds which have been plagued in the field of air quality detection for a long time is solved, especially the effective separation of cyclopentanone, 2-butanone and n-butyraldehyde, which are easy to co-flow, is completed, the problem of mutual interference of the three substances in real application scenarios and cannot be accurately quantified is solved, the blank of detecting cyclopentanone by high performance liquid chromatography is filled, the complete effective separation and accurate quantification of 26 kinds of aldehyde ketone compounds can be completed at one time, multiple analyses are not required, the analysis efficiency is improved, the equipment operation and maintenance are simple, the analysis cost is low, at the same time, the detection limits of each target substance in the detection method provided by the present application are 0.0003~0.0028 μg / mL, compared with the detection method using the same equipment in the prior art, the detection limit is lower and the sensitivity is better; the relative standard deviation (RSD) of each target substance after multiple analyses is 0.09%~1.68%, the method precision is good, and the mobile phase system used has lower toxicity, is more suitable for industrial laboratory and on-site analysis and rapid screening of large quantities of samples, the application scenarios involve atmospheric environmental quality detection, indoor air quality detection, especially vehicle air quality detection and other fields, the application range is wide, and has high practicability. BRIEF DESCRIPTION OF DRAWINGS

[0062] Figure 1 The liquid chromatogram of 26 kinds of aldehyde ketone compounds obtained by the analysis method in Example 1.

[0063] Figure 2 The chromatogram of the blank sample solution in Example 3.

[0064] Figure 3 The chromatogram of the blank sample solution in Example 3.

[0065] Figure 4 The chromatogram obtained by the analysis method in Example 9.

[0066] Figure 5Chromatogram obtained for the analytical method of Example 10.

[0067] Figure 6 Chromatogram obtained for the analytical method of Example 11.

[0068] Figure 7 Chromatogram obtained for the analytical method of Example 12.

[0069] Figure 8 Chromatogram obtained for the analytical method of Example 13.

[0070] Figure 9 Chromatogram obtained for the analytical method of Example 14.

[0071] Figure 10 Chromatogram obtained for Scheme One of Comparative Example 1.

[0072] Figure 11 Chromatogram obtained for Scheme Two of Comparative Example 1.

[0073] Figure 12 Chromatogram obtained for Scheme Three of Comparative Example 1.

[0074] Figure 13 Chromatogram obtained for Scheme One of Comparative Example 2.

[0075] Figure 14 Chromatogram obtained for Scheme Two of Comparative Example 2.

[0076] Figure 15 Chromatogram obtained for Scheme Three of Comparative Example 2.

[0077] Figure 16 Chromatogram obtained for Scheme One of Comparative Example 3.

[0078] Figure 17 Chromatogram obtained for Scheme One of Comparative Example 3, i.e. the partial enlargement of Figure 1. Figure 16

[0079] Figure 18 Chromatogram obtained for Scheme Two of Comparative Example 3, Method A.

[0080] Figure 19 Chromatogram obtained for Scheme Two of Comparative Example 3, Method B.

[0081] Figures 1-19 The aldehyde ketone compounds shown by reference numerals in the figures are as follows:

[0082] ​1. Formaldehyde; 2. Acetaldehyde; 3. Furfuraldehyde; 4. Acrolein; 5. Acetone; 6. Propionaldehyde; 7. Butenal; 8. Methacrolein; 9. 2-Butanone; 10. n-Butyraldehyde; 11. Cyclopentanone; 12. Benzaldehyde; 13. Isovaleraldehyde; 14. Glutaraldehyde; 15. Cyclohexanone; 16. Pentanal; 17. o-Tolualdehyde; 18. m-Tolualdehyde; 19. p-Tolualdehyde; 20. 4-Methyl-2-pentanone; 21. Hexanal; 22. 2,5-Dimethylbenzaldehyde; 23. Heptanal; 24. Octanal; 25. Nonanal; 26. Decanal. DETAILED DESCRIPTION

[0083] In order to make the objectives, technical solutions and effects of the present application clearer and more apparent, the present application is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0084] The terms "comprising", "including", "containing", "have" or "including" or any other variant thereof, are intended to cover non-exclusive inclusion. For example, a composition, step, method, article or apparatus that comprises a list of elements is not necessarily limited to those elements, but can include other elements not expressly listed or inherent to such composition, step, method, article or apparatus.

[0085] "Optional" or "any of" means that the matter or event described thereafter can occur or not occur, and the description includes the case where the event occurs and the case where the event does not occur.

[0086] The indefinite article "a" and "an" before an element or component of the present application does not limit the number of elements or components (i.e., occurrences) to one. Thus, "a" or "an" should be interpreted to cover one or at least one, and the singular form of an element or component includes the plural unless the number is obviously meant to be only one.

[0087] The description of the terms "one embodiment", "some embodiments", "exemplarily", "specific examples" or "some examples" and the like described in the present application means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this document, the illustrative description of the above terms is not necessarily directed to the same embodiment or example.

[0088] The numerical range described in the present application includes not only the point values listed in the embodiments, but also any point values not listed between the numerical ranges described in the present application. Due to the limitation of space and for the sake of simplicity, the present application does not exhaustively list the specific point values included in the range.

[0089] In the following examples, all reagents and consumables were purchased from conventional reagent manufacturers in the art unless otherwise specified.

[0090] In the detection of the air quality in the vehicle, in addition to the formaldehyde, acetaldehyde and propyl aldehyde defined in the air quality evaluation guide for passenger vehicles GB / T 27630-2011, the common aldehyde ketone compounds in the vehicle also include: acetone, furfural, propyl aldehyde, butyl aldehyde, 2-butanone, methyl propyl aldehyde, n-butyl aldehyde, cyclopentanone, benzaldehyde, cyclohexanone, isovaleraldehyde, valeraldehyde, o-methyl benzaldehyde, glutaraldehyde, m-methyl benzaldehyde, p-methyl benzaldehyde, 4-methyl-2-pentanone, hexyl aldehyde, 2,5-dimethyl benzaldehyde, heptyl aldehyde, octyl aldehyde, nonyl aldehyde and decyl aldehyde. These substances have a high frequency of occurrence in daily detection, have a great influence on the physical and mental health of the driver and passenger, and are also the focus of some high-end automobile manufacturers. Therefore, the detection method of the application is especially suitable for the detection of various aldehyde ketone compounds in the air in the vehicle, and the following examples will mainly focus on the specific method of the air quality detection in the vehicle.

[0091] The detection method of the aldehyde ketone compound in the air provided by the application comprises the following steps:

[0092] S1. providing a to-be-detected sample, and placing the to-be-detected sample for pretreatment;

[0093] S2. collecting a background blank sample before starting the test or collecting a blank sample synchronously with the sample, collecting the blank sample of the aldehyde ketone compound by using a sampling tube coated with 2,4-dinitrophenylhydrazine, and obtaining a blank tube;

[0094] S3. collecting the sample gas of the aldehyde ketone compound by using a sampling tube coated with 2,4-dinitrophenylhydrazine after the to-be-detected sample is pretreated and placed for balancing, and obtaining a sample tube;

[0095] S4. eluting the blank tube and the sample tube with acetonitrile respectively, and obtaining a blank solution and a sample solution after constant volume;

[0096] S5. preparing 26 kinds of aldehyde ketone-DNPH derivative mixed standard working solutions with different concentrations, and analyzing and detecting by using a high performance liquid chromatograph and a diode array detector, drawing a standard working curve, and obtaining the regression equation corresponding to each target;

[0097] The aldehyde ketone compound is as follows:

[0098]

[0099] S6. The blank solution and the sample solution are analyzed using a high performance liquid chromatograph, and a diode array detector is used for detection, to obtain the peak area of each target substance in the blank solution and the sample solution. The peak area of each target substance in the sample solution is subtracted from the peak area of each target substance in the blank solution, and is substituted into the corresponding standard curve regression equation to calculate the actual content of 26 kinds of aldehyde ketone compounds in the sample tube after deducting the background blank. Then, the content of 26 kinds of aldehyde ketone compounds in the sample to be tested is obtained through formula conversion.

[0100] The volatile aldehyde ketone pollutants in the air in the vehicle mainly come from the automobile interior parts and materials in the passenger compartment and the luggage compartment. For the field of vehicle air quality detection, the production conditions, environment and transportation environment conditions of automobile interior materials and parts are different. The sample is placed at a specified temperature and humidity for a certain period of time before testing, which is beneficial to the stable state of the sample and better guarantees the parallelism and repeatability of the test results.

[0101] In some specific embodiments, the temperature of the pre-treatment placement is a constant temperature of 20-25℃. As an example, the pre-treatment placement temperature of the sample can also be 21℃, 22℃, 23℃, 24℃, as long as the pre-treatment placement temperature is within this range.

[0102] In some specific embodiments, the relative humidity of the pre-treatment placement is a constant humidity of 40-60%. As an example, the pre-treatment placement humidity can also be 42%, 45%, 46%, 48%, 50%, 51%, 53%, 55%, 58%, as long as the pre-treatment placement humidity is within this range.

[0103] In some specific embodiments, the pre-treatment placement time is 6 hours-7 days. As an example, the pre-treatment placement time can also be 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, as long as the pre-treatment placement time is within this range.

[0104] The principle of high performance liquid chromatography for detecting aldehyde ketone compounds in air is: collecting sample gas through a sampling tube coated with 2,4-dinitrophenylhydrazine filler (DNPH sampling tube). Aldehyde ketone compounds in the air can react with 2,4-dinitrophenylhydrazine (2,4-Dinitrophenylhydrazine, DNPH, CAS.No: 119-26-6) in the sampling tube to generate corresponding hydrazone derivatives, which have absorption at a specific absorption wavelength. After eluting with a certain amount of acetonitrile, the content of the corresponding hydrazone derivatives is detected by a UV detector or a diode array detector (Diode array detector, DAD), so as to obtain the content of the corresponding aldehyde ketone compounds (the target substances involved in the high performance liquid chromatography analysis method in the present application are all described as "aldehyde ketone compounds").

[0105] In some specific embodiments, the balance treatment adopts a 1 cubic meter test cabin sampling method, and the sampling process of the 1 cubic meter test cabin sampling method specifically includes the following steps:

[0106] The automobile interior part is sampled according to the use amount of the whole vehicle, and the interior material is sampled at 1 kg or 1 m 2 , or according to the sampling requirements of the enterprise standard of the automobile manufacturer. Before testing, remove the outer packaging of the sample, and after pretreatment and placement in a constant temperature and humidity room at a temperature of (23±2) ℃ and a relative humidity of (50±5) % for 7 days, start detection.

[0107] After aging of the 1 cubic meter test cabin, the background total hydrocarbon concentration in the cabin is continuously monitored online by FID (less than 1.0 ppm). The balance treatment conditions of the test cabin are set as follows: temperature is 65 ℃, relative humidity is 5%, and gas exchange rate is 0.4 h -1 . After the parameters are stable, collect the background blank tube, and collect the background blank of 26 kinds of aldehyde ketone compounds using the DNPH sampling tube. The sampling parameters are: 1 L / min, and 60 L of cabin gas is collected.

[0108] After the blank sample collection is completed, the sample is placed in the cabin, the cabin door is quickly closed, and the test is started.

[0109] The sample sampling time is 3 h after the sample is placed in the cabin, the sample gas is collected using the DNPH sampling tube, and the sampling parameters are: 1 L / min, and 60 L of cabin gas is collected.

[0110] In some specific embodiments, the balance treatment adopts a sampling bag sampling method, and the sampling process of the sampling bag sampling method specifically includes the following steps:

[0111] The automobile interior part is generally sampled according to the use amount of the whole vehicle, and the interior material is generally sampled at 1 kg or 1 m 2Or according to the requirements of each automobile manufacturer's enterprise standard sampling. Before testing, remove the sample outer packaging, and start testing after pre-treatment and placement for 1-7 days in a constant temperature and humidity room at a temperature of (23±2) °C and a relative humidity of (50±5) %, or the pre-treatment time is required to be carried out according to the provisions in the enterprise standard of each automobile manufacturer.

[0112] The sampling bag is a polyvinyl fluoride sampling bag, and the size is usually 500 L, 1000 L or 2000 L, or other sizes can be used.

[0113] Before sampling, the sampling bag should be cleaned and aged. The inner surface of the sampling bag can be fixed on a support and placed in a constant temperature test box at 80°C for 24h. Put the sample into the aged sampling bag, seal the sampling bag with a sealing strip, use a diaphragm vacuum pump to evacuate the gas in the sampling bag and observe the airtightness. After leak detection is completed, use high-purity nitrogen to replace the gas in the sampling bag, fill 50% of the volume of the sampling bag with nitrogen and shake well, then remove the nitrogen and repeat the operation 2 times. After the gas replacement is completed, accurately fill 50% of the volume of the sampling bag with nitrogen, move the sampling bag to the constant temperature test box, and balance at 60-65°C for 2h, then use a DNPH sampling tube to collect the sample of aldehyde ketone compounds, and the sampling parameters are: 1L / min, collect 60L of gas in the bag.

[0114] The background blank bag is tested in parallel with the sample, and the sampling process and parameters are the same as the sample, except that the sample is not placed.

[0115] In some specific embodiments, the balancing treatment uses a whole vehicle sampling method, and the sampling process of the whole vehicle sampling method specifically includes the following steps:

[0116] The vehicle under test generally meets the condition that the test date is within 28 days±5 days from the off-line date.

[0117] Before testing, adjust the sampling environment parameters of the whole vehicle environment chamber, which should meet the following conditions:

[0118] Temperature: 23.0-25.0°C; relative humidity: 50%±10%.

[0119] Vehicle preparation stage:

[0120] Place the vehicle under test in the sampling whole vehicle VOC environment chamber, remove the surface coverings of the internal components (such as plastic film used to protect the seats, carpets, etc. at the factory), and move the coverings outside the sampling environment chamber. Open the windows and doors of the vehicle under test completely, and pre-treat and place for 6h.

[0121] The environmental cabin environment blank is sampled using the DNPH sampling tube within the last 1 h of the preparation stage. The sampling point is 0.5 m from the vehicle body, with a height consistent with the breathing zone height of the driver and passenger (1.2 m to 1.5 m), and 1 DNPH tube is collected as an environmental blank (detects the environmental background value before testing, and is not involved in the final result calculation).

[0122] Vehicle closed stage:

[0123] The sampling tube is arranged using a support, and the number of sampling points is determined according to the effective volume in the passenger compartment of the vehicle under test and the specific circumstances of the vehicle under test. Among them:

[0124] a) M1 * Class M1 vehicles are arranged with 1 measurement point at the intersection of the front seat headrest connecting line and the vehicle cabin center axis (slidable front seats should be slid to the last position point of the slide rail);

[0125] b) M2 ** Class M2 vehicles are arranged with not less than 2 measurement points, which are evenly arranged along the vehicle cabin center axis;

[0126] c) M3 *** Class M3 vehicles are arranged with not less than 3 measurement points (when the M-class vehicle is a double-decker or articulated passenger car, the measurement points are 6), which are evenly arranged along the vehicle cabin center axis;

[0127] d) N **** Class N vehicles are arranged with 1 measurement point at the intersection of the front seat headrest connecting line and the vehicle cabin center axis.

[0128] Note:

[0129] * Class M1 vehicles refer to motor vehicles with at least four wheels and used for carrying passengers. The number of seats, including the driver's seat, is not more than nine.

[0130] ** Class M2 vehicles refer to motor vehicles with at least four wheels and used for carrying passengers. The number of seats, including the driver's seat, is more than nine, and the maximum design total mass is not more than 5000 kg.

[0131] *** Class M3 vehicles refer to motor vehicles with at least four wheels and used for carrying passengers. The number of seats, including the driver's seat, is more than nine, and the maximum design total mass is more than 5000 kg.

[0132] **** Class N vehicles refer to motor vehicles with at least four wheels and used for carrying goods.

[0133] Each sampling point can be arranged with four different types of sampling tubes for collecting different types of samples, the inlet end height is consistent with the height of the breathing zone of the driver and passenger (1.2-1.5 m), and the outlet end is sealed with a plug to avoid leakage of the vehicle gas from the sampling pipe. The conduit is led out of the passenger compartment in a proper manner without damaging the integrity and sealing of the whole vehicle.

[0134] Close all windows and doors of the test vehicle completely, and balance the process for 16 h.

[0135] Sample collection stage:

[0136] Connect the DNPH sampling tube to the outlet end of the sampling conduit, and collect two DNPH tubes; record the test vehicle conditions, sampling date, time, location, atmospheric pressure, temperature, relative humidity, air flow speed, etc.; sample the background blank sample at the same time, the sampling point is 0.5 m away from the vehicle body, the height is consistent with the height of the breathing zone of the driver and passenger (1.2-1.5 m), and one DNPH tube is collected.

[0137] The sampling parameters of the DNPH blank tube and the sample tube are: the sampling flow rate is 1 L / min, and 60 L of gas is collected.

[0138] In some specific embodiments, the elution and constant volume include the following steps:

[0139] The blank tube and the sample tube are eluted in the reverse direction of the sampling direction using acetonitrile, the eluted eluent is collected in a volumetric flask, and finally acetonitrile is used for constant volume to obtain a blank solution and a sample solution.

[0140] In some specific embodiments, the speed of eluting the blank tube and the sample tube in the reverse direction of the sampling direction in the elution step is 2-3 mL / min. The rate of eluting the sampling tube with acetonitrile is controlled to fully elute the adsorbed and coated chemicals in the sampling tube and transfer them into the volumetric flask.

[0141] In some specific embodiments, the 26 kinds of aldehyde ketone-DNPH derivative mixed standard working solution is prepared from a cyclopentanone-DNPH standard stock solution and a 25-kind aldehyde ketone-DNPH derivative compound mixed standard. The 25-kind aldehyde ketone-DNPH derivative compound mixed standard uses a commercial customized mixed standard solution, which contains the remaining 25 kinds of aldehyde ketone-DNPH derivative compounds in the present application except for the cyclopentanone-DNPH derivative, and each target has a concentration of 15 mg / L and is dissolved in acetonitrile. The cyclopentanone-DNPH derivative compound has no standard product, so it needs to be self-made or obtained by another way.

[0142] In some specific embodiments, the cyclopentanone-DNPH standard stock solution includes the following preparation steps:

[0143] Prepare a hydrochloric acid buffer solution;

[0144] Weigh 2,4-dinitrophenylhydrazine in a volumetric flask, add acetonitrile and ultrasonic oscillation to dissolve;

[0145] Add hydrochloric acid buffer solution to the above solution and mix evenly;

[0146] Weigh cyclopentanone and add it to the above solution for derivatization reaction, so that the molar ratio of 2,4-dinitrophenylhydrazine to cyclopentanone is greater than 2:1, and then use acetonitrile to make up the volume and oscillate in a water bath at 25-45°C for 10-50 minutes.

[0147] The cyclopentanone-DNPH standard stock solution can be obtained through the above preparation steps, and then diluted to the appropriate concentration according to the actual application requirements.

[0148] In some specific embodiments, the concentration of the hydrochloric acid buffer solution in the derivatization reaction process of the cyclopentanone-DNPH standard stock solution preparation is 1-2 mol / L. The main purpose of the hydrochloric acid buffer solution is to adjust the acidity value in the derivatization reaction process, so that it remains in an acidic environment, which is conducive to the rapid and sufficient reaction of aldehyde ketone compounds with DNPH. According to the related existing technology documents for the preparation of aldehyde ketone derivative compounds, the acidity condition of the hydrochloric acid buffer solution in the derivatization reaction process is more appropriate at 1-2 mol / L.

[0149] The preparation process of the cyclopentanone-DNPH standard stock solution is the preparation process used in the present application, and other preparation methods can also be used or customized commercial standards to achieve the same purpose.

[0150] In some specific embodiments, the concentration of the 26 kinds of aldehyde ketone-DNPH derivative mixed standard working solution is 0.006 μg / mL-6 μg / mL. As an example, the concentration of the 26 kinds of aldehyde ketone-DNPH derivative mixed standard working solution can also be 0.01 μg / mL, 0.02 μg / mL, 0.05 μg / mL, 0.1 μg / mL, 0.2 μg / mL, 0.4 μg / mL, 0.5 μg / mL, 1.0 μg / mL, 1.5 μg / mL, 2.0 μg / mL, 3.0 μg / mL, 3.5 μg / mL, 4.0 μg / mL, 5.0 μg / mL, 5.5 μg / mL. Since the present embodiment is mainly aimed at analyzing and testing the aldehyde ketone compounds that may be emitted from the automotive interior materials and parts, the concentration range of the target working solution is adaptively illustrated. If the present embodiment method is used for analysis of other materials and environments, corresponding expansion can be made according to the actual sample and environmental conditions.

[0151] In some specific embodiments, the analysis conditions of the high performance liquid chromatography analysis method are as follows:

[0152] Chromatographic column:

[0153] First chromatographic column: CNW Athena type (C18, 4.6 mm x 250 mm, 5 µm),

[0154] Second chromatographic column: GL Sciences ODS-P type (C18, 4.6 mm x 250 mm, 5 µm),

[0155] The first chromatographic column and the second chromatographic column are connected in series.

[0156] Mobile phase: A phase is water, and B phase is acetonitrile;

[0157] Injection amount: 12 μL;

[0158] Flow rate: 1.0 mL / min;

[0159] Column temperature: 30-40℃;

[0160] Diode array detector, detection wavelength is 367 nm;

[0161] The gradient elution program is as follows:

[0162]

[0163] The focus and difficulty of the present application is also to realize the technical effect of simultaneously effectively separating and accurately quantifying 26 kinds of aldehyde ketone compounds by developing a high performance liquid chromatography analysis method.

[0164] High performance liquid chromatography is the most commonly used detection method for aldehyde ketone compound analysis, and generally uses reversed phase bonded phase chromatography for analysis.

[0165] The separation ability of the chromatographic column plays a crucial role in the separation of target substances. The reversed phase chromatography generally selects a porous silica gel carrier which is treated by acid activation and then reacts with a silanization reagent containing an alkyl chain (C4, C8, C18) or a phenyl group to generate a non-polar stationary phase with an alkyl or phenyl group on the surface, which is suitable for separating non-polar, polar or ionic compounds.

[0166] In this embodiment, two chromatographic columns, CNW Athena type (C18, 4.6 mm x 250 mm, 5 µm) and GL Sciences ODS-P type (C18, 4.6 mm x 250 mm, 5 µm), are connected in series as the analysis chromatographic column system. Both of the two chromatographic columns are reversed phase chromatographic columns bonded with C18 groups, which are suitable for the separation of polar substances such as aldehyde ketone compounds.

[0167] Although both of the two chromatographic columns are C18 reversed-phase chromatographic columns, the separation characteristics of aldehyde ketone compounds are quite different, and the peak time of different types of aldehyde ketone compounds under the same analysis conditions also has certain differences. From some comparative experiments, it can be seen that when the two chromatographic columns are used alone, whether the water-acetonitrile-tetrahydrofuran ternary mobile phase system or the water-acetonitrile binary mobile phase system is used, the 26 kinds of aldehyde ketone compounds cannot be completely separated at the same time. Through the combination of the two chromatographic columns, the respective characteristics are used, and other analysis parameters are developed, the shortcomings of the two chromatographic columns used alone are solved, and the 26 kinds of aldehyde ketone compounds are simultaneously and effectively separated and accurately quantified.

[0168] The tandem combination of chromatographic columns can improve the theoretical plate efficiency to improve the peak capacity, thereby improving the separation degree of the target substance, by referring to the principle of two-dimensional chromatography. However, the tandem combination is different from the modulation cutting function of two-dimensional chromatography. After the sample is separated for the first time by the first chromatographic column, it is all introduced into the second chromatographic column for reseparation. The respective characteristics of the chromatographic columns are different, which may cause the recombination and co-flow of the separated substances with similar properties. Therefore, while selecting suitable chromatographic columns for analysis by using their respective characteristics, it is also necessary to develop suitable elution systems and gradient elution programs.

[0169] In this embodiment, the elution system selects a water-acetonitrile binary mobile phase system. The water-acetonitrile binary mobile phase system is the most commonly used elution system for analyzing aldehyde ketone compounds by high performance liquid chromatography. However, there is no analysis method in the prior art that uses it as an elution system to simultaneously and effectively separate and accurately quantify 26 kinds of aldehyde ketone compounds.

[0170] Therefore, in the prior art, a third phase is added in this binary system to change the performance of the elution system to better improve the separation degree of each target substance. The water-acetonitrile-tetrahydrofuran ternary mixed mobile phase system is thus developed. However, there are still certain deficiencies in its application process, and some difficult-to-separate components cannot be simultaneously and effectively separated. Tetrahydrofuran is a commonly used dipolar solvent. The use of tetrahydrofuran can significantly change the performance parameters of the mobile phase system. However, it has relatively large toxicity and belongs to the 2B carcinogen list published by the International Agency for Research on Cancer of the World Health Organization. Due to the addition of tetrahydrofuran, the noise of the baseline has a certain impact. Compared with the binary system, the baseline noise of the ternary mixed system is slightly larger. Tetrahydrofuran has certain corrosiveness, which may reduce the service life of the quaternary pump assembly and the pipeline in high performance liquid chromatography. The ternary mobile phase system involves the problem of uniform mixing of the mobile phase, which may cause the retention time to deviate after long-term analysis, and the requirement for quality control is higher. Therefore, under the premise of being able to simultaneously and effectively separate and accurately quantify 26 kinds of aldehyde ketone compounds, the water-acetonitrile binary mobile phase system is preferred.

[0171] In the embodiment, the target is separated by using a specially developed gradient elution program. In addition to the mobile phase system, the elution program is another important factor affecting the separation degree of the target. The gradient elution ratio changes in real time with time, and the performance parameters of the system also change in real time, thereby affecting the partitioning equilibrium of the solute molecules between the stationary phase and the mobile phase of the chromatographic column, causing solute molecules of different polarities to be eluted at different time periods and detected by the detector. The mobile phase system is used in cooperation with the elution program, and small differences will cause changes in the performance parameters of the system, affecting the separation degree of the target.

[0172] In the embodiment, the temperature of the chromatographic column is preferably 40°C. The temperature of the chromatographic column has a certain influence on the peak shape, separation degree and retention time of each target on the chromatogram. According to the test results, the column temperature in the range of 30°C to 40°C can meet the technical requirements, and in combination with daily analysis tests, 40°C is preferably selected as the analysis column temperature.

[0173] In the embodiment, the flow rate is selected to be 1.0 mL / min. The flow rate is generally selected according to the type of chromatographic column and the type of sample. Increasing the flow rate can shorten the analysis time but will reduce the separation degree and affect the peak shape. Too low flow rate will prolong the analysis time. Therefore, after experiments, the flow rate of 1.0 mL / min is more appropriate.

[0174] In the embodiment, the injection amount is selected to be 12 μL. The injection amount is generally adjusted according to the type of chromatographic column and the sample to obtain better response and lower signal-to-noise ratio. After experiments, the injection amount of 12 μL is selected in the present application, and other appropriate injection volumes can also be selected.

[0175] In the embodiment, the sample to be analyzed is detected by a diode array detector (DAD) after being separated by high performance liquid chromatography. The diode array detector (DAD) is generally selected for analyzing aldehyde and ketone compounds by high performance liquid chromatography. It is a kind of ultraviolet absorption detector, which uses deuterium lamp as light source and has high analysis sensitivity. The derivative compounds of aldehyde and ketone compounds derived by DNPH have absorption effect on ultraviolet light of a certain wavelength. The commonly used absorption wavelength is 360 nm or 367 nm. The present application selects 367 nm as the wavelength absorption signal of the detector, and 360 nm can also be selected as the absorption wavelength.

[0176] In the embodiment, by developing a specific chromatographic column system, selecting a mobile phase system and developing a specific gradient elution program, the three interact, affect and cooperate with each other to overcome the shortcomings of each technical feature when used alone. In combination with the development of other analysis parameters, the simultaneous and complete effective separation of 26 kinds of aldehyde and ketone compounds based on high performance liquid chromatography is realized for the first time, so as to achieve the technical purpose of accurate quantitative analysis.

[0177] In some specific embodiments, the column temperature in the high performance liquid chromatography analysis method is 30°C or 32°C or 35°C or 40°C. Generally, the temperature of the chromatographic column has certain influence on the peak shape, separation degree and retention time of each target on the chromatogram. According to experiments and daily analysis tests, under the same other analysis parameters, the column temperature in the range of 30°C to 40°C can achieve the purpose of simultaneous effective separation of 26 aldehyde and ketone compounds.

[0178] In some specific embodiments, the analysis conditions of the high performance liquid chromatography analysis method can also be:

[0179] Chromatographic column:

[0180] The first chromatographic column is CNW Athena type (C18, 4.6 mm x 250 mm, 5 μm),

[0181] The second chromatographic column is GL Sciences ODS-P type (C18, 4.6 mm x 250 mm, 5 μm),

[0182] The first chromatographic column and the second chromatographic column are connected in sequence;

[0183] Mobile phase: A phase is water, and B phase is acetonitrile;

[0184] Injection amount: 12 μL;

[0185] Flow rate: 1.0 mL / min;

[0186] Column temperature: 40°C;

[0187] Diode array detector, detection wavelength is 367 nm;

[0188] The gradient elution program is as follows:

[0189]

[0190] In some specific embodiments, the analysis conditions of the high performance liquid chromatography analysis method can also be:

[0191] Chromatographic column:

[0192] The first chromatographic column is CNW Athena type (C18, 4.6 mm x 250 mm, 5 μm),

[0193] The second chromatographic column is GL Sciences ODS-P type (C18, 4.6 mm x 250 mm, 5 μm),

[0194] The first chromatographic column and the second chromatographic column are connected in sequence;

[0195] Mobile phase: A phase is water, B phase is acetonitrile;

[0196] Injection volume: 12 μL;

[0197] Flow rate: 1.0 mL / min;

[0198] Column temperature: 40℃;

[0199] Diode array detector, detection wavelength is 367 nm;

[0200] The gradient elution program is as follows:

[0201]

[0202] In some specific embodiments, the actual content of 26 kinds of aldehyde ketone compounds in the sample tube is calculated according to the standard curve regression equation, and then the actual content of 26 kinds of aldehyde ketone compounds in the sample to be measured is calculated according to the following formula:

[0203]

[0204] In the formula:

[0205] G The volatile amount of the sample to be measured, unit: μg / m 3 ;

[0206] W The content of the compounds captured by the sample tube calculated by the standard curve regression equation, excluding background blank, unit: μg / mL;

[0207] e The constant volume of acetonitrile eluent, mL;

[0208] Q The amount of gas collected in the sample tube is converted according to 23℃, 101.3KPa, unit: L, and the specific conversion formula is as follows:

[0209]

[0210] Wherein:

[0211] V Actual sampling volume, unit: L;

[0212] T The absolute temperature of the sampling point at the time of sampling, unit: K;

[0213] T x The absolute temperature under the reference state, 296.15K;

[0214] P - the atmospheric pressure of the sampling point at the time of sampling, in kPa;

[0215] P x - the atmospheric pressure in the reference state, 101.3 kPa.

[0216] The scheme of the present application will be further described in detail below in combination with specific examples.

[0217] Main instruments and consumables:

[0218] VCE 1000 classic / VOC 1000 1 cubic meter test chamber (Weiss, Germany);

[0219] TESTA FID-2000MP / TESTA-2000MP-BMW volatile organic compounds online monitoring system (online FID, TESTA, Germany);

[0220] V-BIR-56 / V-BIR-30 constant temperature test chamber (Dongguan Mingchi);

[0221] GM-2 dual-purpose diaphragm vacuum pump (Tianjin Teng);

[0222] VA-144 whole vehicle VOC environment chamber (Dongguan Mingchi);

[0223] S401 four-channel sampling pump (Ningbo Huanche Experimental Instrument Co., Ltd.);

[0224] GilAir Plus high and low constant current air sampling pump (SENSIDYNE, USA);

[0225] Gilibrator-2 soap film flowmeter (SENSIDYNE, USA);

[0226] Agilent 1260 Infinity high-performance liquid chromatograph equipped with diode array detector (DAD) (Agilent, USA);

[0227] SK8210HP ultrasonic cleaner (Shanghai Keduo Ultrasonic);

[0228] XS105DU electronic balance (Switzerland Mettler);

[0229] SHZ-C water bath constant temperature oscillator (Shanghai Bozhen Instrument);

[0230] H18091C pipette (Eppendorf, Germany);

[0231] DNPH sampling tube (Ningbo Huanyu Experiment Equipment Co., Ltd., Waters);

[0232] Polyvinyl fluoride sampling bag (Tedlar sampling bag, Ningbo Huanyu Experiment Equipment Co., Ltd., 2000L).

[0233] Standard substance:

[0234] 25 kinds of aldehyde ketone-DNPH derivative compounds mixed standard (customized standard solution, each target concentration is 15 mg / L dissolved in acetonitrile, containing the DNPH derivatives of the following aldehyde ketone compounds: formaldehyde, acetaldehyde, furfuraldehyde, propylene aldehyde, acetone, propionaldehyde, butenyl aldehyde, methyl propylene aldehyde, 2-butanone, n-butyraldehyde, benzaldehyde, isovaleraldehyde, glutaraldehyde, cyclohexanone, pentanal, o-methyl benzaldehyde, m-methyl benzaldehyde, p-methyl benzaldehyde, 4-methyl-2-pentanone, hexanal, 2,5-dimethyl benzaldehyde, heptanal, octanal, nonanal and decanal), purchased from Fint Standard;

[0235] Cyclopentanone (98.77%), purchased from Dr. Ehrenstorfer;

[0236] Hydrochloric acid (37%), purchased from Jiangsu Qiangsheng Functional Chemical Co., Ltd.;

[0237] 2,4-dinitrophenylhydrazine (DNPH, ≥99.0%), purchased from Yonghua Chemical Technology (Jiangsu) Co., Ltd.;

[0238] Acetonitrile and tetrahydrofuran (chromatographic pure reagent, Shanghai Xingke High-purity Solvent Co., Ltd.);

[0239] Water (ultra-pure water, filtered by ultra-pure water instrument Molgene 1805V-UP type, meeting the laboratory first-class water requirements);

[0240] Chromatographic column: CNW Athena type (C18, 4.6 mm×250 mm, 5 µm), Shanghai Anpu Experiment Technology Co., Ltd.;

[0241] Chromatographic column: GL Sciences ODS-P type (C18, 4.6 mm×250 mm, 5 µm), Shimadzu Corporation, Japan.

[0242] Preparation of standard solution:

[0243] 1. Preparation of cyclopentanone-DNPH standard stock solution:

[0244] Preparation of hydrochloric acid buffer solution:

[0245] Take 5g of 37% hydrochloric acid into a 10ml volumetric flask, add water to constant volume and shake well to prepare a hydrochloric acid buffer solution with a concentration of about 5mol / L;

[0246] In a 50ml brown volumetric flask, add a small amount of acetonitrile, weigh a certain amount of 2,4-dinitrophenylhydrazine (DNPH) into the volumetric flask, and record the actual weight (accurate to 0.00001g); after ultrasonic oscillation to make it fully dissolved as much as possible, add 10ml of hydrochloric acid buffer solution and mix well; weigh a certain amount of cyclopentanone (accurate to 0.00001g) into the volumetric flask, so that the DNPH is excessive, and the molar ratio (DNPH: aldehyde ketone) is greater than 2:1; constant volume with acetonitrile, oscillate in a 40℃ water bath for 20 minutes (keep the actual concentration of hydrochloric acid buffer solution in the derivatization reaction between 1~2mol / L). The cyclopentanone-DNPH standard stock solution is obtained.

[0247] Transfer the above solution into a 1L brown volumetric flask, wash the 50ml volumetric flask with acetonitrile several times, combine the washing liquid into the 1L brown volumetric flask, and constant volume with acetonitrile to obtain the cyclopentanone-DNPH (I grade) standard stock solution;

[0248] Take 50ml of cyclopentanone-DNPH (I grade) standard stock solution into a 500ml brown volumetric flask with a pipette, constant volume with acetonitrile to obtain the cyclopentanone-DNPH (II grade) standard stock solution.

[0249] According to the above steps and calculation, the cyclopentanone-DNPH standard stock solution used in the examples of the present application has a concentration (calculated as aldehyde ketone) of:

[0250] Cyclopentanone-DNPH (I grade) standard stock solution: 270.72857mg / L;

[0251] Cyclopentanone-DNPH (II grade) standard stock solution: 27.072857mg / L;

[0252] The standard stock solution is stored at 0~5℃.

[0253] The above cyclopentanone-DNPH standard stock solution preparation process is the preparation process used in the present application, other preparation methods can also be used or customized commercial standards to achieve the same purpose.

[0254] 2. Preparation of 26 kinds of aldehyde ketone-DNPH derivative mixed standard working solution:

[0255] A. 25 kinds of aldehyde ketone-DNPH derivative compounds mixed standard (15mg / L dissolved in acetonitrile);

[0256] B. Cyclopentanone-DNPH (II grade) standard stock solution (27.072857mg / L dissolved in acetonitrile);

[0257] Take 25 kinds of aldehyde ketone-DNPH derivative compound mixed label, concentration 15 mg / L. Respectively, 0.8 μL, 8 μL, 40 μL, 80 μL, 200 μL, 400 μL, 800 μL in 7 2mL capacity bottle accurately removed;

[0258] Take cyclopentanone-DNPH (Ⅱ level) standard stock solution again, concentration 27.072857 mg / L. Respectively, 0.44 μL, 4.43 μL, 22.16 μL, 44.32 μL, 110.81 μL, 221.62 μL, 443.25 μL, respectively, add above from low to high one by one corresponding 7 2mL capacity bottle;

[0259] Using acetonitrile to constant volume, 26 kinds of aldehyde ketone-DNPH derivative mixed standard working solution is prepared, and the concentration of each substance is 0.006 μg / mL, 0.06 μg / mL, 0.3 μg / mL, 0.6 μg / mL, 1.5 μg / mL, 3 μg / mL, 6 μg / mL. The standard working solution is stored at 0-5℃.

[0260] Example 1

[0261] Take 0.006 μg / mL, 0.06 μg / mL, 0.3 μg / mL, 0.6 μg / mL, 1.5 μg / mL, 3 μg / mL, 6 μg / mL of 26 kinds of aldehyde ketone-DNPH derivative mixed standard working solution, and analyze according to the following analysis parameters:

[0262] Liquid chromatography conditions:

[0263] Chromatographic column:

[0264] First chromatographic column: CNW Athena type (C18, 4.6 mm×250 mm, 5 μm),

[0265] Second chromatographic column: GL Sciences ODS-P type (C18, 4.6 mm×250 mm, 5 μm),

[0266] Chromatographic column is connected in order;

[0267] Mobile phase: A phase is water, B phase is acetonitrile;

[0268] Injection volume: 12 μL;

[0269] Flow rate: 1.0 mL / min;

[0270] Column temperature: 40℃;

[0271] Diode array detector, detection wavelength 367 nm;

[0272] The gradient elution program is as follows:

[0273]

[0274] The standard working curve of 26 target substances was fitted with the concentration of each target substance in the standard working solution as the abscissa and the corresponding response value of each target substance as the ordinate. The working curve was forced to pass through the origin to obtain the linear regression equation and the correlation coefficient. The linear correlation coefficient of each target substance r >0.999, which proves that it has a good linear relationship in the range of 0.006-6 μg / mL. Figure 1 The obtained liquid chromatograms of 26 aldehyde ketone compounds (concentration 0.6 μg / mL), the retention time of 26 aldehyde ketone compounds, the linear equation and the linear correlation coefficient are shown in Table 1.

[0275]

[0276] Example 2

[0277] Take 10 μL of 26 aldehyde ketone-DNPH derivative mixed standard working solution with a concentration of 3 μg / mL and add it to the DNPH sampling tube from the sampling port direction to simulate the sampling state. Use the calibrated sampling pump at a flow rate of 1 L / min to collect 60 L of air. After sealing the sampling tube, place it in an aluminum foil bag and place it in a designated environment for 2 h. Then elute it with acetonitrile. The environmental parameters during the simulation of the sampling and placement process are as follows: in a constant temperature and humidity clean cabin with a temperature of (23±2) ℃, a relative humidity of (50±5) %, and a background hydrocarbon concentration of <1 ppm. The elution process is as follows:

[0278] Use a disposable syringe to draw a certain amount of acetonitrile and elute it in the reverse direction of the sampling direction, controlling the elution speed to be 2-3 mL / min. The eluent is collected in a 5 ml volumetric flask and finally diluted to 5 mL. Finally, transfer it into a 2 mL sample vial and analyze it by HPLC.

[0279] According to the above test steps, the theoretical concentration value of the sample solution is the concentration value of the linear minimum concentration point, which is 0.006 μg / mL.

[0280] Repeat the test for 10 parallel samples, analyze them according to the liquid chromatography conditions in Example 1, and calculate the detection limit (LOD μg / mL) of 26 target substances according to the 3 times standard deviation of the parallel sample results. The detection limit is low and the sensitivity is good. When the gas sampling amount is 60 L and the elution volume is 5 mL of acetonitrile solution, the corresponding method detection limit (LOD μg / mL) is calculated to be 0.0003-0.0028 μg / mL. 3), considering the actual test conditions, the linear concentration of the standard working solution was selected as 0.006 μg / mL, which was converted to the concentration of each target compound as 0.5 μg / m 3 As the method limit of quantification (LOQ μg / m 3 The method detection limit and the method limit of quantification corresponding to each target compound are shown in Table 2.

[0281]

[0282] Example 3

[0283] The principle of high performance liquid chromatography for determining aldehyde and ketone compounds is to detect the hydrazone derivatives corresponding to the aldehyde and ketone compounds by a UV detector or a diode array detector (DAD) at a certain absorption wavelength. This method has high selectivity. In order to exclude the possibility of matrix interference, according to the liquid chromatography conditions in Example 1, the intermediate mass concentration point 0.6 μg / mL of the 26 kinds of aldehyde and ketone-DNPH derivative mixed standard working solution was used as the theoretical concentration to perform blank test and blank spiked test, and the specificity of the method was investigated.

[0284] The blank spiked recovery rate test was performed by adding a certain volume of standard working solution (80 μL of 25 kinds of aldehyde and ketone-DNPH derivative compounds mixed standard (15 mg / L dissolved in acetonitrile) and 44.32 μL of cyclopentanone-DNPH (grade II) standard stock solution) into the DNPH sampling tube together to simulate the sampling state. The calibrated sampling pump was used to collect 60 L of air at a flow rate of 1 L / min. After the sampling tube was sealed and placed in an aluminum foil bag, it was placed in a designated environment (temperature (23±2) ℃, relative humidity (50±5) %) for 2 h. Then, acetonitrile was used for elution (elution process was the same as that in Example 2, but the eluent was collected in a 2 mL volumetric flask and finally diluted to 2 mL) and HPLC analysis was performed. The blank sample was tested in parallel, and the test process was the same as that of the spiked sample, except that no standard working solution was added.

[0285] The chromatograms of the blank solution and the blank spiked solution are shown in FIGS. 1 and 2, respectively. As can be seen from FIG. 3, there is no interfering substance in the blank sample, and there is no interfering substance overlapping with the chromatographic peak of the target compound in the blank spiked sample, which meets the specificity requirement of the method. Figure 2 Figure 3 Figures 1-3

[0286] Example 4

[0287] The method precision and accuracy were investigated with the intermediate concentration standard working solution theoretical value of 0.6 μg / mL:

[0288] ​​​Take 80 μL of 25 aldehyde ketone-DNPH derivative compound mixed label mother liquor with a concentration of 15 μg / mL and 44.32 μL of cyclopentanone-DNPH (grade II) standard stock solution from the sampling port and add them into the DNPH sampling tube together to simulate the sampling state. Use the calibrated sampling pump to collect 60 L of air at a flow rate of 1 L / min. After the sampling tube is sealed, it is placed in an aluminum foil bag. After being placed in the designated environment for 2 h, it is eluted with acetonitrile (the elution process is the same as in Example 2, but the eluent is collected in a 2 mL volumetric flask and finally diluted to 2 mL). The environmental parameters during the simulation sampling and placement process are as follows: the process is carried out in a constant temperature and humidity clean cabin with a temperature of (23±2) °C, a relative humidity of (50±5) %, and a background hydrocarbon concentration of <1 ppm.

[0289] The above method is repeated for 6 parallel samples, and the relative standard deviations (RSDs) of the 26 target substances are 0.09% to 1.68% after analysis under the liquid chromatography conditions in Example 1, indicating good precision of the method. The recoveries and relative errors of the 26 target substances are calculated, and the relative errors are <10%, meeting the accuracy requirements. The comprehensive evaluation shows that the accuracy of the method meets the analysis requirements. The relative standard deviations, recoveries, and relative errors of the 26 aldehyde ketone compounds are shown in Table 3.

[0290]

[0291] Example 5

[0292] Take 1 m 2 of the automobile interior composite planar material sample. Remove the outer packaging of the sample before testing. After being placed in a constant temperature and humidity room with a temperature of (23±2) °C and a relative humidity of (50±5) % for 7 days of pretreatment, the detection is started.

[0293] After aging for 1 cubic meter of the test cabin, the background total hydrocarbon concentration in the cabin is continuously monitored online by FID (which should be less than 1.0 ppm). The test cabin equilibrium treatment conditions are set as follows: the temperature is 65 °C, the relative humidity is 5%, and the gas exchange rate is 0.4 h -1 After the parameters are stable, the background blank tube is collected, and the DNPH sampling tube is used to collect the background blank sample of the 26 aldehyde ketone compounds. The sampling parameters are as follows: 1 L / min, and 60 L of cabin gas is collected.

[0294] After the blank sample collection is completed, the sample is placed in the cabin, the door is quickly closed, and the test is started.

[0295] The sample sampling time is 3 h after the sample is placed in the cabin. The DNPH sampling tube is used to collect the sample gas. The sampling parameters are as follows: 1 L / min, and 60 L of cabin gas is collected.

[0296] The sample tube and the blank tube after sampling were eluted according to the elution procedure in Example 2 to obtain a sample solution and a blank solution. 0.006 μg / mL, 0.06 μg / mL, 0.3 μg / mL, 0.6 μg / mL, 1.5 μg / mL, 3 μg / mL, 6 μg / mL of 26 kinds of aldehyde ketone-DNPH derivative mixed standard working solutions were taken, and the eluted sample solution and the blank solution were analyzed by the liquid chromatography according to the conditions in Example 1.

[0297] The standard working curve of the 26 kinds of aldehyde ketones was drawn by taking the concentration of each target analyte as the abscissa and the corresponding response value as the ordinate, and the standard working curve was forced to pass through the origin, and the correlation coefficient was greater than 0.999. r

[0298] The peak area of each target in the sample obtained by instrument analysis was subtracted from the corresponding blank peak area, and the content (μg / mL) was calculated according to the standard working curve of each target, and then the content of each target in the actual sample was calculated according to the following formula:

[0299]

[0300] In the formula:

[0301] G The volatile amount of the sample to be tested, unit: μg / m 3 ;

[0302] W The content of the compound captured by the sample tube after deducting the background blank, calculated by the standard curve regression equation, unit: μg / mL;

[0303] e The constant volume of acetonitrile eluent, mL;

[0304] Q The amount of gas collected in the sample tube according to 23℃, 101.3 KPa, unit: L, and the specific conversion formula is as follows:

[0305]

[0306] In the formula:

[0307] V The actual sampling volume, unit: L;

[0308] T The absolute temperature of the sampling point during sampling, unit: K;

[0309] T x ​Absolute temperature in the reference state, 296.15 K;

[0310] P Atmospheric pressure at the sampling point at the time of sampling, unit: kPa;

[0311] P x Atmospheric pressure in the reference state, 101.3 kPa.

[0312] The sample analysis results are shown in Table 4.

[0313]

[0314] Note: N.D. is not detected.

[0315] Example 6

[0316] Take one piece of the front seat assembly of the car interior. Before testing, remove the outer packaging of the sample, and after pretreatment and placement in a constant temperature and humidity room at a temperature of (23±2) ℃ and a relative humidity of (50±5) % for 24 h, start the detection.

[0317] The size of the sampling bag is 2000 L.

[0318] Put the sample into the aged sampling bag, seal the sampling bag with a sealing strip, use a diaphragm vacuum pump to evacuate the gas in the sampling bag and observe the airtightness. After leak detection is completed, use high-purity nitrogen to replace the gas in the sampling bag, fill 50% of the volume of the sampling bag with nitrogen and shake well, then evacuate the nitrogen and repeat the operation 2 times. After replacement is completed, accurately fill 50% of the volume of the sampling bag with nitrogen, move the sampling bag to the constant temperature test box, and after equilibration treatment at 60℃ for 2 h, use a DNPH sampling tube to collect the sample of aldehyde ketone compounds, and the sampling parameters are: 1 L / min, collect 60 L of gas in the bag.

[0319] The background blank bag is tested in parallel with the sample, and the preparation process, sampling process and parameters are the same as those of the sample, except that the sample is not placed.

[0320] The elution of the sample tube and the blank tube, instrument analysis and result calculation process are the same as those of Example 5.

[0321] The sample analysis results are shown in Table 5.

[0322]

[0323] Note: N.D. is not detected, and "<0.5" means that there is detection but lower than the limit of quantification.

[0324] Example 7

[0325] Take a whole vehicle as the test sample. Before testing, adjust the sampling environment of the VOC environmental chamber of the whole vehicle, and set it to:

[0326] Temperature: 23.0℃; Relative humidity: 50%.

[0327] Vehicle preparation phase:

[0328] Place the vehicle under inspection into the vehicle sampling VOC environmental chamber, remove the coverings from the surfaces of the internal components, and move the coverings outside the sampling environmental chamber. Fully open all windows and doors of the vehicle under inspection and allow it to sit for 6 hours for pretreatment.

[0329] During the final hour of the preparation phase, DNPH sampling tubes were used to sample the environmental blank in the environmental chamber. The sampling point was 0.5 meters away from the vehicle body, at the same height as the breathing zone of the driver and passengers (1.2 meters to 1.5 meters). One DNPH tube was collected as the environmental blank (the environmental background value before the test is detected and is not included in the final result calculation).

[0330] Vehicle closure phase:

[0331] The sampling pipeline was arranged using a bracket, and one sampling point was set up inside the vehicle at the intersection of the line connecting the front seat headrests and the central axis of the vehicle.

[0332] The height of the sampling point inlet should be consistent with the breathing belt height of the driver and passengers (1.2 meters to 1.5 meters), and the outlet end should be sealed with a plug to prevent gas leakage from the vehicle through the sampling pipeline. The sampling tubing should be led out from the vehicle door without compromising the integrity and airtightness of the vehicle.

[0333] Completely close all windows and doors of the vehicle under inspection, and allow it to settle for 16 hours after balancing.

[0334] Sample collection stage:

[0335] Connect the sample tube to the outlet end of the sampling catheter and collect two DNPH tubes; record the vehicle condition, sampling date, time, location, atmospheric pressure, temperature, relative humidity, airflow speed, etc.; at the same time, sample the background blank sample, the sampling point is 0.5m from the vehicle body, the height is consistent with the breathing belt height of the driver and passengers (1.2m~1.5m), and collect one DNPH tube.

[0336] The sampling parameters for DNPH blank tubes and sample tubes were as follows: sampling flow rate was 1 L / min, and 60 L of gas was collected.

[0337] The elution, instrumental analysis, and result calculation procedures for sample tubes and blank tubes are the same as in Example 5.

[0338] The sample analysis results are shown in Table 6.

[0339]

[0340] Note: ND means not detected, "<0.5" means detected but below the limit of quantitation.

[0341] Example 8

[0342] The detection method of the present application can be applied to the field of environmental air, indoor air quality detection, etc. Taking the application of the analysis method in the present application to the detection of aldehyde ketone compounds in indoor air as an example.

[0343] The sampling method refers to the indoor air quality standard GB / T 18883-2022, and the organic pre-treatment room of the chemical laboratory is taken as the sampling object.

[0344] Before sampling, close the doors and windows, air purification equipment and fresh air system for 12 hours. During sampling, the doors and windows, air purification equipment and fresh air system should still be kept closed.

[0345] Single-point sampling is arranged at the center of the house. The sampling point should be away from the air vent, the distance from the wall should be greater than 0.5 m, and the distance from the door and window should be greater than 1 m. The sampling point height is consistent with the height of the human respiratory zone, and the arrangement height is 1.4 m.

[0346] According to the foregoing steps, connect the sampling tube with the sampling pump, adjust the appropriate sampling flow rate, and complete the calibration of the sampling equipment, then start collecting the air sample.

[0347] The sampling parameters of the DNPH sample tube are: the sampling flow rate is 1 L / min, and 60 L of gas is collected.

[0348] The elution and instrument analysis process of the sample tube are the same as in Example 5.

[0349] Then calculate the content of each target substance in the air of the sampling object according to the following formula:

[0350]

[0351] In the formula:

[0352] G’ The concentration of each target substance in the air, unit: μg / m 3 ;

[0353] W’ The content of the compound captured by the sample tube calculated by the standard curve regression equation, unit: μg / mL;

[0354] e The constant volume of acetonitrile eluent, mL;

[0355] Q According to 23 ℃, 101.3 KPa, the amount of gas collected in the sample tube is converted, unit: L, and the specific conversion formula is as follows:

[0356]

[0357] wherein:

[0358] V - actual sample volume, unit: L;

[0359] T - absolute temperature of sampling point at sampling, unit: K;

[0360] T x - absolute temperature in reference state, 296.15 K;

[0361] P - atmospheric pressure of sampling point at sampling, unit: kPa;

[0362] P x - atmospheric pressure in reference state, 101.3 kPa.

[0363] The sample analysis results are shown in Table 7.

[0364]

[0365] Note: N.D. is not detected.

[0366] Example 9

[0367] This example is a verification example for verifying the analysis parameters of the liquid chromatograph, specifically as follows:

[0368] Liquid chromatography conditions:

[0369] Chromatographic column:

[0370] First chromatographic column: CNW Athena type (C18, 4.6 mm x 250 mm, 5 µm),

[0371] Second chromatographic column: GL Sciences ODS-P type (C18, 4.6 mm x 250 mm, 5 µm),

[0372] The chromatographic columns are connected in order;

[0373] Mobile phase: A phase is water, B phase is acetonitrile;

[0374] Injection volume: 12 μL;

[0375] Flow rate: 1.0 mL / min;

[0376] Column temperature: 40℃;

[0377] Diode array detector, detection wavelength is 367 nm;

[0378] The gradient elution procedure is as follows:

[0379]

[0380] A 26-component aldehyde ketone-DNPH derivative mixed standard working solution of 0.6 μg / mL was analyzed according to the above analysis parameters, and the obtained chromatogram is shown in FIG. 6. As can be seen from FIG. 6, the analysis method in this embodiment can meet the requirements of simultaneous complete and effective separation and accurate quantification of 26 aldehyde ketone compounds, and the technical effect is basically equivalent to that of the analysis method in Example 1. Figure 4 Figure 4

[0381] Example 10

[0382] This embodiment is a verification example for verifying the analysis parameters of the liquid chromatograph, and is specifically as follows:

[0383] Liquid chromatograph conditions:

[0384] Chromatographic column:

[0385] First chromatographic column: CNW Athena type (C18, 4.6 mm x 250 mm, 5 μm),

[0386] Second chromatographic column: GL Sciences ODS-P type (C18, 4.6 mm x 250 mm, 5 μm),

[0387] The chromatographic columns are connected in order;

[0388] Mobile phase: A phase is water, and B phase is acetonitrile;

[0389] Injection volume: 12 μL;

[0390] Flow rate: 1.0 mL / min;

[0391] Column temperature: 40°C;

[0392] Diode array detector, detection wavelength is 367 nm;

[0393] The gradient elution procedure is as follows:

[0394]

[0395] A 26-component aldehyde ketone-DNPH derivative mixed standard working solution of 0.6 μg / mL was analyzed according to the above analysis parameters, and the obtained chromatogram is shown in FIG. 6. As can be seen from FIG. 6, the analysis method in this embodiment can meet the requirements of simultaneous complete and effective separation and accurate quantification of 26 aldehyde ketone compounds, and the technical effect is basically equivalent to that of the analysis method in Example 1. Figure 5 Figure 5 ​​​It can be seen that the analytical method in this embodiment can simultaneously and effectively separate and accurately quantify 26 aldehyde and ketone compounds. Compared with the analytical method in Example 1, the separation degree of glutaraldehyde 14 and cyclohexanone 15 is poor, but it still meets the analytical requirements. Therefore, the analytical parameters in this method are critical parameters for achieving simultaneous and effective separation of 26 aldehyde and ketone compounds.

[0396] Example 11

[0397] This example is a verification example of liquid chromatography analytical parameters, as detailed below:

[0398] Liquid chromatography conditions:

[0399] Chromatographic column:

[0400] First chromatographic column: CNW Athena type (C18, 4.6 mm × 250 mm, 5 µm),

[0401] Second chromatographic column: GL Sciences ODS-P type (C18, 4.6 mm × 250 mm, 5 µm),

[0402] The chromatographic columns are connected in sequence;

[0403] Mobile phases: Phase A is water, and Phase B is acetonitrile;

[0404] Injection volume: 12 μL;

[0405] Flow rate: 1.0 mL / min;

[0406] Column temperature: 40℃;

[0407] Diode array detector, with a detection wavelength of 367 nm;

[0408] The gradient elution procedure is as follows:

[0409]

[0410] A mixed standard working solution of 26 aldehyde and ketone-DNPH derivatives at a concentration of 0.6 μg / mL was prepared and analyzed according to the above analytical parameters. The resulting chromatogram is shown in the attached figure. Figure 6 As shown. From the appendix Figure 6 It can be seen that the analytical method in this embodiment can simultaneously and effectively separate and accurately quantify 26 aldehydes and ketones, achieving the technical effect desired by this invention. Compared with the analytical method in Example 1, 2-butanone 9 and n-butyraldehyde 10 can be effectively separated, but their chromatographic peaks gradually approach each other, proving that subtle changes in the gradient elution program have a certain impact on the resolution of difficult-to-separate components.

[0411] Example 12

[0412] This embodiment is a verification example of verifying the analysis parameters of the liquid chromatograph, specifically as follows:

[0413] Liquid chromatography conditions:

[0414] Chromatographic column:

[0415] First chromatographic column: CNW Athena type (C18, 4.6 mm x 250 mm, 5 µm),

[0416] Second chromatographic column: GL Sciences ODS-P type (C18, 4.6 mm x 250 mm, 5 µm),

[0417] The chromatographic columns are connected in order;

[0418] Mobile phase: A phase is water, and B phase is acetonitrile;

[0419] Injection volume: 12 µL;

[0420] Flow rate: 1.0 mL / min;

[0421] Column temperature: 35°C;

[0422] Diode array detector, detection wavelength is 367 nm;

[0423] Gradient elution program is as follows:

[0424]

[0425] Take 0.6 µg / mL of 26 kinds of aldehyde ketone-DNPH derivative mixed standard working solution, and analyze according to the above analysis parameters, and the obtained chromatogram is shown in FIG. 2. As shown in FIG. 2, the analysis method in this embodiment can meet the complete and effective separation and accurate quantification of 26 kinds of aldehyde ketone compounds at the same time, and the technical effect is basically equivalent to that of the analysis method in Example 1. Figure 7 Figure 7 It can be seen from FIG. 2 that the analysis method in this embodiment can meet the complete and effective separation and accurate quantification of 26 kinds of aldehyde ketone compounds at the same time, and the technical effect is basically equivalent to that of the analysis method in Example 1.

[0426] Example 13

[0427] This embodiment is a verification example of verifying the analysis parameters of the liquid chromatograph, specifically as follows:

[0428] Liquid chromatography conditions:

[0429] Chromatographic column:

[0430] First chromatographic column: CNW Athena type (C18, 4.6 mm x 250 mm, 5 µm),

[0431] ​Second chromatographic column: GL Sciences ODS-P type (C18, 4.6 mm × 250 mm, 5 µm),

[0432] The chromatographic columns are connected in sequence;

[0433] Mobile phases: Phase A is water, and Phase B is acetonitrile;

[0434] Injection volume: 12 μL;

[0435] Flow rate: 1.0 mL / min;

[0436] Column temperature: 32℃;

[0437] Diode array detector, with a detection wavelength of 367nm;

[0438] The gradient elution procedure is as follows:

[0439]

[0440] A mixed standard working solution of 26 aldehyde and ketone-DNPH derivatives at a concentration of 0.6 μg / mL was prepared and analyzed according to the above analytical parameters. The resulting chromatogram is shown in the attached figure. Figure 8 As shown. From the appendix Figure 8 It can be seen that the analytical method in this embodiment can completely and effectively separate and accurately quantify 26 aldehyde and ketone compounds at the same time, and its technical effect is basically equivalent to that of the analytical method in Example 1.

[0441] Example 14

[0442] This example is a verification example of liquid chromatography analytical parameters, as detailed below:

[0443] Liquid chromatography conditions:

[0444] Chromatographic column:

[0445] First chromatographic column: CNW Athena type (C18, 4.6 mm × 250 mm, 5 µm),

[0446] Second chromatographic column: GL Sciences ODS-P type (C18, 4.6 mm × 250 mm, 5 µm),

[0447] The chromatographic columns are connected in sequence;

[0448] Mobile phases: Phase A is water, and Phase B is acetonitrile;

[0449] Injection volume: 12 μL;

[0450] Flow rate: 1.0 mL / min;

[0451] Column temperature: 30℃;

[0452] Diode array detector, detection wavelength: 367 nm;

[0453] The gradient elution program is as follows:

[0454]

[0455] Take 0.6 μg / mL of 26 kinds of aldehyde ketone-DNPH derivative mixed standard working solution, and analyze according to the above analysis parameters, and the obtained chromatogram is shown in FIG. 2. As shown in FIG. 2, the analysis method in the embodiment can meet the complete and effective separation and accurate quantification of 26 kinds of aldehyde ketone compounds. Compared with the analysis method in Example 1, the chromatographic peaks of cyclohexanone 15 and pentanal 16 gradually approach, but have no effect on the separation effect. Overall, the technical effect obtained by the analysis method in the embodiment is basically equivalent to the technical effect obtained by the analysis method in Example 1. Figure 9 Figure 9 As can be seen from FIG. 2, the analysis method in the embodiment can meet the complete and effective separation and accurate quantification of 26 kinds of aldehyde ketone compounds. Compared with the analysis method in Example 1, the chromatographic peaks of cyclohexanone 15 and pentanal 16 gradually approach, but have no effect on the separation effect. Overall, the technical effect obtained by the analysis method in the embodiment is basically equivalent to the technical effect obtained by the analysis method in Example 1.

[0456] Comparative Example 1

[0457] In order to further prove that the technical effect provided by the method of the present application is better than that of the prior art, comparative tests are now carried out.

[0458] The chromatographic column is one of the important factors for realizing the technical effect of the present application. The CNW Athena type (C18, 4.6 mm x 250 mm, 5 μm) chromatographic column is a commercial high-performance liquid chromatographic column, which is suitable for separating non-polar, polar or ionic compounds. At the same time, it is also the closest prior art (Chinese invention patent application, application number 202411163439.6) chromatographic column searched. Therefore, using this chromatographic column, the remaining analysis parameters used in the present application except the chromatographic column system, the analysis parameters (water-acetonitrile-tetrahydrofuran ternary mobile phase system) in the Chinese invention patent application (application number 202411163439.6) and the water-acetonitrile binary mobile phase system are used in combination with the fast gradient elution program to investigate the separation capacity of the CNW Athena chromatographic column for 26 kinds of aldehyde ketone compounds. The specific experimental conditions are as follows:

[0459] Scheme 1. Analyze using the same analysis conditions as the present application:

[0460] Liquid chromatography conditions:

[0461] Chromatographic column: CNW Athena type (C18, 4.6 mm x 250 mm, 5 μm);

[0462] Mobile phase: A phase is water, B phase is acetonitrile; ​

[0463] Injection volume: 12 μL;

[0464] Flow rate: 1.0 mL / min;

[0465] Column temperature: 40℃;

[0466] Diode array detector, detection wavelength was 367 nm;

[0467] The gradient elution program was as follows:

[0468]

[0469] Scheme two. Analyzed using water-acetonitrile-tetrahydrofuran ternary mobile phase system:

[0470] The analysis parameters were in the Chinese invention patent application (application number 202411163439.6, invention name: A method for detecting 25 kinds of aldehyde ketone compounds in automobile interior materials and parts).

[0471] Liquid chromatography conditions:

[0472] Chromatographic column: CNW Athena type (C18, 4.6 mm×250 mm, 5 µm) ;

[0473] Mobile phase: A phase was water, B phase was acetonitrile, and D phase was tetrahydrofuran;

[0474] Injection volume: 20 μL;

[0475] Flow rate: 1.0 mL / min;

[0476] Column temperature: 40℃;

[0477] Diode array detector, detection wavelength was 367 nm;

[0478] The gradient elution program was as follows:

[0479]

[0480] Scheme three. Analyzed using water-acetonitrile binary mobile phase system:

[0481] Analyzed using water-acetonitrile binary mobile phase system with rapid detection gradient elution program.

[0482] Liquid chromatography conditions:

[0483] Chromatographic column: CNW Athena type (C18, 4.6 mm×250 mm, 5 µm) ;

[0484] Mobile phase: A phase was water, B phase was acetonitrile;

[0485] Injection volume: 12 μL;

[0486] Flow rate: 1.2 mL / min;

[0487] Column temperature: 40℃;

[0488] Diode array detector, detection wavelength is 367 nm;

[0489] The gradient elution program is as follows:

[0490]

[0491] Take 0.6 μg / mL of 26 kinds of aldehyde ketone-DNPH derivative mixed standard working solution, respectively according to the above analysis scheme one to three, the obtained chromatograms are respectively as shown in the following table: Figures 10-12

[0492] From the attached Figure 10 It can be seen that using CNW Athena type (C18, 4.6 mm x 250 mm, 5 μm) chromatographic column, scheme one cooperates with the mobile phase system and gradient elution parameters of the present application, cannot complete the simultaneous effective separation of 26 kinds of aldehyde ketone compounds, among which furfuraldehyde 3 and acrolein 4, n-butyl aldehyde 10 and cyclopentanone 11 are co-eluted and cannot be separated, m-methylbenzaldehyde 18 and p-methylbenzaldehyde 19 can only be slightly separated at the top peak close to co-elution, these groups of substances are compounds that are more difficult to separate simultaneously in aldehyde ketone compound analysis.

[0493] Scheme two uses the analysis method in the closest prior art, using water-acetonitrile-tetrahydrofuran ternary mobile phase system, also cannot complete the simultaneous separation of 26 kinds of aldehyde ketone compounds, from the attached Figure 11 It can be seen that 2-butanone 9 and cyclopentanone 11, m-methylbenzaldehyde 18 and p-methylbenzaldehyde 19 are co-eluted and cannot be separated.

[0494] Scheme three uses a fast analysis method, using water-acetonitrile binary mixed system cooperates with the corresponding gradient elution parameters, but it also cannot complete the simultaneous separation of 26 kinds of aldehyde ketone compounds, from the attached Figure 12 It can be seen that furfuraldehyde 3 and acrolein 4, n-butyl aldehyde 10 and cyclopentanone 11 are co-eluted and cannot be separated, m-methylbenzaldehyde 18 and p-methylbenzaldehyde 19 can only be slightly separated at the top peak close to co-elution, and the co-elution combination thereof is the same as that in scheme one.

[0495] ​Therefore, it can be inferred that using the CNW Athena type (C18, 4.6 mm x 250 mm, 5 µm) chromatographic column cannot achieve the technical effect of simultaneous effective separation of 26 kinds of aldehyde ketone compounds and the technical purpose of accurate quantification whether it is matched with a ternary mobile phase system or a binary mobile phase system, or the same mobile phase system is matched with different gradient elution procedures.

[0496] Comparative Example 2

[0497] In order to further prove that the technical effect of the method provided by the present application is better than that of the prior art, a comparative test is now carried out.

[0498] The GL Sciences ODS-P type (C18, 4.6 mm x 250 mm, 5 µm) chromatographic column is also a commercial high-performance liquid chromatographic column suitable for separating non-polar, polar or ionic compounds, and is another chromatographic column used in the present application. Therefore, using this chromatographic column, the remaining analysis parameters used in the present application except for the chromatographic column system, the analysis parameters (water-acetonitrile-tetrahydrofuran ternary mobile phase system) in the Chinese invention patent application (application number 202411163439.6) and the water-acetonitrile binary mobile phase system matched with the rapid gradient elution procedure are used respectively to investigate the separation capacity of the GL Sciences ODS-P chromatographic column for 26 kinds of aldehyde ketone compounds. The specific experimental conditions are as follows:

[0499] Scheme 1. Analysis is carried out using the same analysis conditions as the present application:

[0500] Liquid chromatography conditions:

[0501] Chromatographic column: GL Sciences ODS-P type (C18, 4.6 mm x 250 mm, 5 µm);

[0502] Mobile phase: A phase is water, B phase is acetonitrile;

[0503] Injection volume: 12 µL;

[0504] Flow rate: 1.0 mL / min;

[0505] Column temperature: 40℃;

[0506] Diode array detector, detection wavelength is 367 nm;

[0507] Gradient elution program is as follows:

[0508]

[0509] Scheme 2. Analysis is carried out using a water-acetonitrile-tetrahydrofuran ternary mobile phase system:

[0510] The chromatographic column was GL Sciences ODS-P, and the rest of the analysis parameters were the parameters in the Chinese Invention Patent Application (Application No. 202411163439.6, Invention Name: A Method for Detecting 25 Aldehyde and Ketone Compounds in Automotive Interior Materials and Parts).

[0511] Liquid chromatography conditions:

[0512] Chromatographic column: GL Sciences ODS-P type (C18, 4.6 mm x 250 mm, 5 µm) ;

[0513] Mobile phase: A phase was water, B phase was acetonitrile, and D phase was tetrahydrofuran;

[0514] Injection volume: 20 µL;

[0515] Flow rate: 1.0 mL / min;

[0516] Column temperature: 40℃;

[0517] Diode array detector, detection wavelength was 367 nm;

[0518] The gradient elution program was as follows:

[0519]

[0520] Scheme three. Analysis was performed using a water-acetonitrile binary mobile phase system:

[0521] Analysis was performed using a water-acetonitrile binary mobile phase system with a rapid detection gradient elution program.

[0522] Liquid chromatography conditions:

[0523] Chromatographic column: GL Sciences ODS-P type (C18, 4.6 mm x 250 mm, 5 µm) ;

[0524] Mobile phase: A phase was water, B phase was acetonitrile;

[0525] Injection volume: 12 µL;

[0526] Flow rate: 1.2 mL / min;

[0527] Column temperature: 40℃;

[0528] Diode array detector, detection wavelength was 367 nm;

[0529] The gradient elution program was as follows:

[0530]

[0531] Take 0.6 μg / mL of 26 aldehyde ketone-DNPH derivative mixed standard working solution, respectively according to the above one to three analysis scheme for analysis, the chromatogram obtained is shown in the attached Figures 13-15

[0532] From the attached Figure 13 It can be seen that using GL Sciences ODS-P type (C18, 4.6 mm x 250 mm, 5 μm) chromatographic column, scheme one with the mobile phase system and gradient elution parameters of the present application, cannot complete the simultaneous separation of 26 kinds of aldehyde ketone compounds, among which 2-butanone 9 and n-butyraldehyde 10 are co-eluted and cannot be separated, and the separation degree of the co-eluted chromatographic peak and cyclopentanone 11 chromatographic peak is poor, which can only be slightly separated at the peak top; at the same time, 2,5-dimethylbenzaldehyde 22 and cyclohexanone 15 have poor separation degree and can only be slightly separated at the peak top.

[0533] Scheme two uses the analysis method in the closest prior art, using a water-acetonitrile-tetrahydrofuran ternary mobile phase system, which also cannot complete the simultaneous separation of 26 kinds of aldehyde ketone compounds, from the attached Figure 14 It can be seen that furfural 3 and acrolein 4, 2-butanone 9 and cyclopentanone 11, glutaraldehyde 14 and o-methylbenzaldehyde 17, hexanal 21 and 2,5-dimethylbenzaldehyde 22 are co-eluted and cannot be separated, and m-methylbenzaldehyde 18 and p-methylbenzaldehyde 19 can only be separated at the peak top with poor separation degree. Using ODS-P chromatographic column with the analysis parameters in this scheme, the results obtained have more groups of target co-eluted, proving the difference between the chromatographic columns and the influence of the mutual coordination of the mobile phase system, gradient elution program and the three on the separation degree of the target.

[0534] Scheme three uses a fast analysis method, using a water-acetonitrile binary mixed system with the corresponding gradient elution parameters, but it also cannot complete the simultaneous separation of 26 kinds of aldehyde ketone compounds, from the attached Figure 15 It can be seen that 2-butanone 9 and n-butyraldehyde 10 are co-eluted and cannot be separated, and the separation degree of the co-eluted chromatographic peak and cyclopentanone 11 chromatographic peak is poor, which can only be slightly separated at the peak top; at the same time, 2,5-dimethylbenzaldehyde 22 and cyclohexanone 15 have poor separation degree and can only be slightly separated at the peak top, and the co-eluted substance combination and the substance combination with poor separation degree in this scheme are the same as scheme one.

[0535] Therefore, it can be inferred that using GL Sciences ODS-P type (C18, 4.6 mm x 250 mm, 5 μm) chromatographic column, whether with a ternary mobile phase system or a binary mobile phase system, or the same mobile phase system with different gradient elution programs, cannot achieve the technical effect of simultaneous effective separation and the technical purpose of accurate quantification of 26 kinds of aldehyde ketone compounds.

[0536] ​From Comparative Examples 1 and 2, it can be seen that the two types of chromatographic columns used in the present application have different performances, and the separation ability of 26 aldehyde ketone compounds using the same analysis parameters has certain differences, and the outflow time and order of some aldehyde ketone compounds also have certain differences. Several groups of substances that cannot be separated simultaneously are several groups of compounds that are difficult to separate simultaneously in aldehyde ketone compounds. It can be seen that the two types of chromatographic columns used in the present application cannot complete the technical effect of simultaneous and complete separation of 26 aldehyde ketone compounds when used alone, whether in combination with a ternary mobile phase system or a binary mobile phase system, or the same mobile phase system with different gradient elution programs, so as to complete the purpose of quantifying 26 aldehyde ketone compounds in one analysis.

[0537] Comparative Example 3

[0538] In order to further prove that the technical effect of the method provided by the present application is better than that of the prior art, a comparative test is now carried out.

[0539] Based on the analysis of a plurality of aldehyde ketone compounds by high performance liquid chromatography, the chromatographic column, the elution system and the matching gradient elution program are the three most critical factors that determine the separation degree of the target substance, and the mutual interaction and cooperation among the three play a crucial role in the final separation effect. The more the types of target substances are, the more the combinations of difficult-to-separate compounds with similar properties involved, and the higher the requirements for the analysis parameters are. Each parameter in the analysis method needs to be coordinated, and small changes can lead to changes in the separation degree of the target substance, thereby affecting the realization of the technical effect of the method of the present application. Comparative Examples 1 and 2 respectively investigate the influence of the chromatographic column, and this comparative example investigates the separation of 26 aldehyde ketone compounds required to be separated by the analysis method in the prior art, i.e. the mobile phase system and the gradient elution program, under the condition of using the same double-column series. The specific experimental conditions are as follows:

[0540] Scheme 1. Using a ternary mobile phase system of water-acetonitrile-tetrahydrofuran for analysis:

[0541] Using the tandem chromatographic column system of the present application, the remaining analysis parameters use the parameters in the Chinese invention patent application (application number 202411163439.6, invention name: A method for detecting 25 aldehyde ketone compounds in automobile interior materials and parts).

[0542] Liquid chromatography conditions:

[0543] Chromatographic column:

[0544] First chromatographic column: CNW Athena type (C18, 4.6 mm x 250 mm, 5 µm),

[0545] Second chromatographic column: GL Sciences ODS-P type (C18, 4.6 mm x 250 mm, 5 µm),

[0546] The chromatographic columns are connected in sequence.

[0547] Mobile phase: A phase is water, B phase is acetonitrile, and D phase is tetrahydrofuran.

[0548] Injection volume: 20 µL;

[0549] Flow rate: 1.0 mL / min;

[0550] Column temperature: 40℃;

[0551] Diode array detector, detection wavelength is 367 nm.

[0552] The gradient elution program is as follows:

[0553]

[0554] Scheme II. The water-acetonitrile binary mobile phase system and the matching gradient elution program reported in the existing literature are used for analysis:

[0555] Method A:

[0556] The analysis method for 25 kinds of aldehyde ketone carbonyl compounds in the air established by Li Lirong et al. (paper title: Determination of 25 kinds of aldehyde ketone compounds in air by liquid chromatography and liquid chromatography-mass spectrometry), the target substances overlap more with the present application, but the developed high performance liquid chromatography method cannot separate cyclohexanone and glutaraldehyde as co-elution, and p-methylbenzaldehyde can only be separated at the peak top. Now try to use the double column series system, combined with the mobile phase system and the matching gradient elution program in the HPLC method developed by it, and the remaining analysis parameters except the chromatographic column, to analyze the 26 kinds of aldehyde ketone compounds in the present application, and the specific analysis conditions are as follows.

[0557] Liquid chromatography conditions:

[0558] Chromatographic column:

[0559] First chromatographic column: CNW Athena type (C18, 4.6 mm x 250 mm, 5 µm),

[0560] Second chromatographic column: GL Sciences ODS-P type (C18, 4.6 mm x 250 mm, 5 µm),

[0561] The chromatographic columns are connected in sequence.

[0562] Mobile phase: A phase is water, B phase is acetonitrile;

[0563] Injection volume: 10 μL;

[0564] Flow rate: 1.0 mL / min;

[0565] Column temperature: 40℃;

[0566] Diode array detector, detection wavelength is 367 nm;

[0567] The gradient elution program is as follows:

[0568]

[0569] Method B:

[0570] The method for 25 kinds of aldehyde ketone compounds in wood products established by Wang Wei et al. (paper title: Simultaneous determination of 25 kinds of aldehyde ketone compounds in wood products by DNPH derivatization-solvent analysis-high performance liquid chromatography), from the spectrum, it can be seen that 2-butanone and n-butyl aldehyde, cyclohexanone and pentanal cannot be effectively separated. The 25 kinds of aldehyde ketone compounds in the method are slightly different from the target aldehyde ketone compounds in the application, but most of them overlap, so the analysis parameters of the method are used to try to analyze the 26 kinds of aldehyde ketone compounds required to be separated in the application. Try to use a double-column tandem system, combined with the mobile phase system and the matching gradient elution program developed by it, and the rest of the analysis parameters except the chromatographic column, to compare and analyze the 26 kinds of aldehyde ketone compounds in the application. The specific analysis conditions are as follows.

[0571] Liquid chromatography conditions:

[0572] Chromatographic column:

[0573] First chromatographic column: CNW Athena type (C18, 4.6 mm×250 mm, 5 µm),

[0574] Second chromatographic column: GL Sciences ODS-P type (C18, 4.6 mm×250 mm, 5 µm),

[0575] The chromatographic columns are connected in order;

[0576] Mobile phase: A phase is water, B phase is acetonitrile;

[0577] Injection volume: 20 μL;

[0578] Flow rate: 1.0 mL / min;

[0579] Column temperature: 30℃;

[0580] Diode array detector, detection wavelength is 367 nm;

[0581] The gradient elution program is as follows:

[0582]

[0583] Take 0.6 μg / mL of 26 kinds of aldehyde ketone-DNPH derivative mixed standard working solution, respectively according to the above one or two analysis scheme for analysis, the chromatogram obtained respectively as shown in Figures 16-19 .

[0584] The patent literature cited in scheme one is in the same technical field as the present application, the technical problem to be solved is most similar, and the most technical features are disclosed, which is the closest prior art. Using double column series and combining the remaining analysis parameters disclosed, 26 kinds of aldehyde ketone compounds are analyzed, and the obtained Figures 16-17 . From the Figure 16 and Figure 17 , it can be seen that this method cannot complete the technical purpose of completely and effectively separating 26 kinds of aldehyde ketone compounds at the same time, among which furfural 3 and acrolein 4, methyl acrolein 8 and 2-butanone 9 cannot be separated, hexanal 21 and 2,5-dimethyl benzaldehyde 22 can only be separated at the top peak with poor separation degree, and the separation degree of glutaraldehyde 14 and pentanal 16 is also poor. Due to the influence of the water-acetonitrile-tetrahydrofuran ternary mobile phase system on the elution capacity of the solute, the peak time of each target is later than that of the water-acetonitrile binary mobile phase system, resulting in that octanal 24, nonanal 25 and decanal 26 are not eluted within the method collection time, and the signals of the corresponding substances are not collected. From the Figure 16 and Figure 17 obtained by scheme one and the Figure 11 obtained by scheme two in comparative example 1, it can be seen that the substances that can be completely separated by using the same mobile phase system and gradient elution program and the same parameters except the chromatographic column (such as furfural 3 and acrolein 4, methyl acrolein 8 and 2-butanone 9) are combined and co-eluted in the double column series system, which proves that although the double column series system is beneficial to improve the separation degree of the target, the different properties of the series chromatographic columns may cause the combination and co-elution of the separated substances, and the separation effect may not be better than that when the single column is separated. Therefore, for the development of the analysis method of multiple kinds of aldehyde ketone compounds, simply using the series chromatographic columns cannot improve the separation degree of the target, and verification tests in many aspects still need to be carried out on the selection of the series columns, the selection of the mobile phase system and the development of the gradient elution program.

[0585] The two methods in scheme two all use the same water-acetonitrile binary mobile phase system as the present application, in order to investigate the influence of the gradient elution program on the separation degree under the condition that the remaining analysis parameters are unchanged, 26 kinds of target aldehyde ketone compounds are compared and analyzed by using the analysis parameters reported in the scheme two and the double column series system of the present application. From the Figure 18(Method A) As can be seen, the analysis method parameters cannot complete the simultaneous complete effective separation of 26 kinds of aldehyde ketone compounds, in which 2-butanone 9 and n-butyraldehyde 10 can only be slightly separated from the top peak close to co-elution, cyclohexanone 15 and pentanal 16 are co-eluted and cannot be separated. From the attached Figure 19 (Method B) As can be seen, the analysis method parameters also cannot complete the simultaneous complete effective separation of 26 kinds of aldehyde ketone compounds, in which 2-butanone 9 and n-butyraldehyde 10, cyclohexanone 15 and pentanal 16 are co-eluted and cannot be separated, and nonanal 25 and decanal 26 are not eluted within the method collection time, and the signals of the corresponding substances are not collected.

[0586] The two liquid chromatography methods in the two prior art references cited in Scheme II have certain defects in separating their respective 25 target compounds, and cannot complete the simultaneous effective separation of the corresponding target aldehyde ketone compounds; and after comparing and analyzing 26 kinds of aldehyde ketone compounds using a tandem column system combined with the corresponding remaining analysis parameters, there are still multiple groups of difficult-to-separate compound combinations that cannot be separated simultaneously, which also reflects from another aspect that simply increasing the column length of the chromatography column cannot solve the problem of target separation degree, and still requires the development of various analysis parameters in a coordinated manner.

[0587] As can be seen from the comparison experiments of methods A / B in Scheme II, even if the same double-column tandem system, the same mobile phase elution system, and the same gradient elution parameters are used, the analysis results (retention time, separation degree, etc.) still have large differences, and the simultaneous complete effective separation of 26 kinds of aldehyde ketone compounds cannot be achieved. In high-performance liquid chromatography analysis methods, each analysis parameter cooperates with and influences each other. In order to complete the complete separation of multiple types of target substances with similar properties, it is necessary to simultaneously develop the three most critical technical parameters of the chromatography column, the mobile phase system, and the gradient elution program in a coordinated manner, while also coordinating the flow rate, column temperature, and other parameters to achieve the technical purpose. A slight difference will lead to a difference in results, and affect the final technical effect of the analysis method. The appropriate analysis parameters can only be obtained through a large number of experiments, and cannot be obtained by conversion or simple transformation. The development of parameters also needs to consider the stability, repeatability, analysis efficiency, and analysis cost of the method, and finally determine the most appropriate analysis parameters to achieve the desired technical effect.

[0588] In the above two schemes, the substances that cannot be separated simultaneously are the combination of the more difficult-to-separate substances among the 26 aldehyde ketone compounds, which further illustrates the influence of the parameter combination of the chromatographic column, the mobile phase system and the gradient elution program on the separation degree of the 26 aldehyde ketone compounds. Through the experiments in the present comparative example, it can be inferred that even if the double-column series system in the present application is used, if there is no suitable mobile phase system and the matching gradient elution program, the technical purpose of simultaneously and completely effectively separating and accurately quantifying the 26 aldehyde ketone compounds cannot be achieved.

[0589] It should be understood that the application of the present application is not limited to the above examples, and those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes shall belong to the protection scope of the appended claims of the present application.

Claims

1. A method for detecting aldehydes and ketones in the air, characterized in that, Includes the following steps: S1. Provide the sample to be tested, pre-treat the sample, and set it aside for later use; S2. Before starting the test, collect a background blank sample or collect a blank sample simultaneously with the sample. Use a sampling tube coated with 2,4-dinitrophenylhydrazine to collect blank samples of aldehydes and ketones to obtain a blank tube. S3. After the pretreatment of the sample to be tested is completed, it is equilibrated and then sampled using a sampling tube coated with 2,4-dinitrophenylhydrazine to collect the sample gas of aldehyde and ketone compounds to obtain the sample tube. S4. Use acetonitrile to elute the blank tube and the sample tube respectively, and then make up to volume to obtain blank solution and sample solution; S5. Prepare mixed standard working solutions of 26 aldehyde-ketone-DNPH derivatives of different concentrations and analyze them using high performance liquid chromatography with the aid of a diode array detector. Plot standard working curves and obtain the regression equations corresponding to each target analyte. The aldehyde and ketone compounds are the following 26 types: Formaldehyde, acetaldehyde, furanaldehyde, acrolein, acetone, propionaldehyde, butenaldehyde, methacrolein, 2-butanone, n-butanaldehyde, cyclopentanone, benzaldehyde, isovaleraldehyde, glutaraldehyde, cyclohexanone, pentanal, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, 4-methyl-2-pentanone, hexanal, 2,5-dimethylbenzaldehyde, heptanal, octanal, nonanal, decanal; S6. High performance liquid chromatography (HPLC) was used to analyze the blank solution and the sample solution, and a diode array detector was used for detection. The peak areas of each target compound in the blank solution and the sample solution were obtained. The peak areas of each target compound in the blank solution were subtracted from the peak areas of each target compound in the sample solution and substituted into the corresponding standard curve regression equations to calculate the actual content of 26 aldehyde and ketone compounds in the sample tube after deducting the background blank. The content of 26 aldehyde and ketone compounds in the sample to be tested was then calculated using the formula. The analytical conditions for high performance liquid chromatography are as follows: Chromatographic column: First chromatographic column: CNW Athena C18 column, 4.6 mm × 250 mm, 5 µm. Second chromatographic column: GL Sciences ODS-P C18 column, 4.6 mm × 250 mm, 5 µm. The first and second chromatographic columns are connected in series in sequence; Mobile phases: Phase A is water, and Phase B is acetonitrile; Injection volume: 12 μL; Flow rate: 1.0 mL / min; Column temperature: 30~40℃; Diode array detector, with a detection wavelength of 367nm; The gradient elution procedure is as follows: At 0 min, the proportion of mobile phase A was 40%, and the proportion of mobile phase B was 60%. After 25 minutes, the proportion of mobile phase A was 35%, and the proportion of mobile phase B was 65%. After 30 minutes, the proportion of mobile phase A was 0%, and the proportion of mobile phase B was 100%. After 40 minutes, the proportion of mobile phase A was 0%, and the proportion of mobile phase B was 100%. After 45 minutes, the proportion of mobile phase A was 40% and the proportion of mobile phase B was 60%.

2. The method for detecting aldehydes and ketones in the air according to claim 1, characterized in that, The pretreatment is carried out at a constant temperature of 20-25°C and a constant relative humidity of 40-60%, and the pretreatment time is 6 hours to 7 days.

3. The method for detecting aldehydes and ketones in the air according to claim 1, characterized in that, The balancing process employs a 1 cubic meter test chamber sampling method, in which a background blank sample is collected before the test begins. Alternatively, the balancing process employs a sampling bag method, in which blank bags are used for parallel testing, and blank samples are collected synchronously with the sample collection. Alternatively, the balancing process may employ a whole-vehicle sampling method, in which blank samples are collected simultaneously with the sample collection.

4. The method for detecting aldehydes and ketones in the air according to claim 3, characterized in that, The equilibrium processing temperature for the 1 cubic meter test chamber sampling method and the sampling bag sampling method is 60℃~65℃, and the equilibrium processing temperature for the whole vehicle sampling method is 23.0℃~25.0℃.

5. The method for detecting aldehydes and ketones in the air according to claim 1, characterized in that, The elution and volume adjustment process includes the following steps: The blank tube and sample tube were eluted with acetonitrile in the opposite direction of the sampling direction. The eluent was collected in a volumetric flask and diluted to volume with acetonitrile to obtain the blank solution and sample solution.

6. The method for detecting aldehydes and ketones in the air according to claim 5, characterized in that, The elution rate of acetonitrile in the opposite direction of the sampling direction for the blank tube and the sample tube is 2-3 mL / min.

7. The method for detecting aldehydes and ketones in the air according to claim 1, characterized in that, The mixed standard working solution of the 26 aldehyde and ketone-DNPH derivatives was prepared by mixing cyclopentanone-DNPH standard stock solution and 25 aldehyde and ketone-DNPH derivative compounds.

8. The method for detecting aldehydes and ketones in the air according to claim 7, characterized in that, The cyclopentanone-DNPH standard stock solution comprises the following preparation steps: Prepare hydrochloric acid buffer solution; Weigh 2,4-dinitrophenylhydrazine into a volumetric flask, add acetonitrile, and dissolve by ultrasonic oscillation; Add hydrochloric acid buffer solution to the above solution and mix well; Weigh out cyclopentanone and add it to the above solution to carry out a derivatization reaction, so that the molar ratio of 2,4-dinitrophenylhydrazine to cyclopentanone is greater than 2:

1. After making up to volume with acetonitrile, shake the reaction in a water bath at 25~45℃ for 10~50 minutes.

9. The method for detecting aldehydes and ketones in the air according to claim 8, characterized in that, During the derivatization reaction process for preparing the cyclopentanone-DNPH standard stock solution, the concentration of the hydrochloric acid buffer solution is 1~2 mol / L.

10. The method for detecting aldehydes and ketones in air according to claim 1, characterized in that, The concentration of the mixed standard working solution of the 26 aldehydes and ketones-DNPH derivatives is 0.006 μg / mL to 6 μg / mL.

11. The method for detecting aldehydes and ketones in the air according to claim 1, characterized in that, The actual content of 26 aldehydes and ketones in the sample tube after background blank was calculated from the standard curve regression equation. Then, the actual content of 26 aldehydes and ketones in the test sample was calculated using the following formula: In the formula: G —Volatile amount of the sample to be tested, unit: μg / m³ 3 ; W —The concentration of compounds captured in the sample tube after deducting the background blank, calculated from the standard curve regression equation, in μg / mL; e —The final volume of the acetonitrile eluent, in mL; Q —Calculate the amount of gas collected in the sample tube based on 23℃ and 101.3 kPa, in L. The specific conversion formula is as follows: In the formula: V —Actual sampling volume, unit: L; T —The absolute temperature of the sampling point at the time of sampling, in K; T x —Absolute temperature under reference conditions, 296.15 K; P —Atmospheric pressure at the sampling point during sampling, unit: kPa; P x —Atmospheric pressure under reference conditions, 101.3 kPa.

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