Method for detecting content of carrageenal in water based on gas chromatography-mass spectrometry

Abstract

The invention provides a method for detecting the content of karanal in water based on gas chromatography-mass spectrometry, which comprises the following steps: sample pretreatment, sample detection, establishment of a standard curve linear equation and result calculation, and the sample pretreatment comprises the following steps: A, transferring a water sample to a separating funnel, adding an extracting agent, oscillating for 8-12 minutes, standing for 2-4 minutes for layering, and collecting a sample; collecting extract liquor, repeatedly extracting for 2-4 times, and combining the extract liquor; and B, dehydrating the extract by using a dehydrating agent, carrying out nitrogen blowing concentration, fixing the volume to 0.5-2.0 mL by using a solvent, and detecting by using a gas chromatography-mass spectrometer. The gas chromatography-mass spectrometry for detecting the content of the carrageenan aldehyde in the water is provided by taking a water sample as a detection matrix, has the advantages of short pretreatment time, high efficiency and good method stability, and can meet the detection requirements of the carrageenan aldehyde in the water sample.

Description

Technical Field

[0001] The present invention relates to the field of detection technology, and particularly to a method for detecting the content of karanal in water quality based on gas chromatography-mass spectrometry Background Art

[0002] Karanal, also known as 2-(2,4-dimethyl-3-cyclohexyl)-5-methyl-5-(1-methylpropyl)-1,3-dioxane, is a very powerful and diffusive raw material. It has a dry ambergris woody fragrance. It is applicable to various applications from perfumes to soaps and washing powders. Due to its excellent fabric fragrance retention ability, it is commonly found in textiles and daily chemical products and is used as a fragrance. However, it has been found that this substance is not easily biodegradable and has strong bioaccumulation, and has been classified as a vPvB (very persistent and very bioaccumulative) substance. The REACH Directive of the European Union included karanal in the 13th batch of restricted substances in June 2015, requiring that the mass fraction in consumer products should not be greater than 0.1%, but no specific detection method was given

[0003] In the past half century, the chemical industry has developed vigorously, and the production and usage of the chemical industry have increased sharply. Therefore, the safety, health, and environmental problems in the use process of the chemical industry have attracted more and more extensive attention. As a material that has been widely used, karanal is very likely to appear in the environment, thus posing a great threat to people's health and the environment. Therefore, the detection of karanal in the environment is of great significance

[0004] The invention patent with the publication number of CN110095548A discloses a method for determining the total content of karanal isomers in coatings, including the following steps: (1) spiking test: according to the spiking test, obtain suitable extraction solvents, extraction methods, extraction times, and conditions for whether the sample needs to be purified by an extraction column; (2) extraction treatment of solid samples, powder coating samples, and liquid samples: use an extraction solvent to extract to obtain a test solution; (3) draw a standard working curve: select a mixture of karanal isomers as a standard product, prepare solutions with different concentrations, and determine them by gas chromatography-electron impact ionization source mass spectrometry, and then draw a standard working curve; (4) determination of the test sample: determine the test solution in step (2) by gas chromatography-electron impact ionization source mass spectrometry, and calculate the total content of karanal isomers in the coating according to the standard working curve in step (3)

[0005] However, the existing detection methods have the disadvantages of low efficiency and unstable detection results in actual use Summary of the Invention

[0006] The purpose of the present invention is to provide a method for detecting the content of kalahexal in water quality based on gas chromatography - mass spectrometry. The present invention has the advantages of short pretreatment time, high efficiency, and good method stability, and can meet the detection requirements of kalahexal in water quality samples.

[0007] To solve the above - mentioned technical problems, the technical solution adopted by the present invention is:

[0008] A method for detecting the content of kalahexal in water quality based on gas chromatography - mass spectrometry, including sample pretreatment, sample detection, establishment of a standard curve linear equation, and result calculation. The sample pretreatment includes the following steps:

[0009] A. Transfer the water sample to a separatory funnel, add the extraction agent, shake for 8 - 12 minutes, let it stand for 2 - 4 minutes to separate layers, collect the extract and repeat extraction 2 - 4 times, and combine the extracts;

[0010] B. After dehydrating the extract with a dehydrating agent, concentrate it by nitrogen blowing, and make the volume constant to 0.5 - 2.0 mL with a solvent, and detect it using a gas chromatography - mass spectrometer.

[0011] Among them, the extraction agent and the solvent are a mixed solvent of petroleum ether and chloroform, and the volume ratio of the two is 1:1.

[0012] Further, in step A, the volume of the water sample transferred is 80 - 120 mL, and the dosage of the extraction agent each time is 10 - 20 mL.

[0013] Further, the dehydrating agent is anhydrous sodium sulfate.

[0014] Further, the gas chromatography conditions include:

[0015] The chromatographic column is an SH - I - 5MS capillary column or an equivalent chromatographic column, with an inner diameter of 25 - 35 m×0.20 - 0.30 mm and a film thickness of 0.20 - 0.30 μm;

[0016] The temperature - rising program is an initial temperature of 80 - 120 °C, maintained for 0.3 - 1.0 minute, heated at 8 - 12 °C / min to 260 - 300 °C, and maintained for 3 - 7 minutes;

[0017] The inlet temperature is 250 - 290 °C, and the injection volume is 0.5 - 1.5 μL.

[0018] Further, the mass spectrometry conditions include:

[0019] The ionization mode is EI, the ion source temperature is 210 - 250 °C, and the ionization energy is 60 - 80 eV;

[0020] The solvent delay time is 3 - 5 minutes, and the scanning mode is SIM mode.

[0021] Further, the establishment of the standard curve linear equation includes:

[0022] Prepare standard working solutions of 6 isomers of furanocoumarin, with a concentration range of 0.05 - 50.0 mg / L. After detection by gas chromatography - mass spectrometry, perform linear fitting with the concentration as the abscissa and the area of the quantitative ion peak as the ordinate.

[0023] Further, the solvent of the standard working solution is a mixed solvent of petroleum ether and chloroform with a volume ratio of 1:1.

[0024] Further, the detection limit of the method is 0.3 - 0.6 μg / L, the total detection time ≤ 35 minutes / sample, and the precision RSD ≤ 1.5%.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention uses water quality samples as the detection matrix and provides a gas chromatography - mass spectrometry method for detecting the content of furanocoumarin in water quality. The present invention has the advantages of short pretreatment time, high efficiency, and good method stability, and can meet the detection requirements of furanocoumarin in water quality samples. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0028] Figure 1 It is the standard working curve plotted with the concentration of the reference substance as the abscissa and the peak area as the ordinate.

[0029] Figure 2 It is the total ion current chromatogram of furanocoumarin in the water sample. Specific Embodiments

[0030] In the following, only some exemplary embodiments are simply described. As those skilled in the art can recognize, without departing from the spirit or scope of the embodiments of the present invention, the described embodiments can be modified in various different ways. Therefore, the drawings and descriptions are considered to be exemplary in nature rather than restrictive. The embodiments of the present invention will be described in detail below with reference to the drawings.

[0031] Example 1

[0032] This embodiment discloses a method for detecting the content of karanaldehyde in water quality based on gas chromatography - mass spectrometry, which includes sample pretreatment, sample detection, establishment of the standard curve linear equation and result calculation. The sample pretreatment includes the following steps:

[0033] A. Transfer the water sample to a separatory funnel, add the extractant, shake for 8 - 12 minutes, let it stand for 2 - 4 minutes to separate layers, collect the extract and repeat extraction 2 - 4 times, then combine the extracts;

[0034] B. After dehydrating the extract with a dehydrating agent, concentrate it by nitrogen blowing, dilute it to 0.5 - 2.0 mL with a solvent, and detect it using a gas chromatography - mass spectrometer.

[0035] Among them, the extractant and the solvent are a mixed solvent of petroleum ether and chloroform, and the volume ratio of the two is 1:1.

[0036] Further, in step A, the volume of the water sample transferred is 80 - 120 mL, and the dosage of the extractant each time is 10 - 20 mL.

[0037] Further, the dehydrating agent is anhydrous sodium sulfate.

[0038] Further, the gas chromatography conditions include:

[0039] The chromatographic column is a SH - I - 5MS capillary column or an equivalent chromatographic column, with an inner diameter of 25 - 35 m×0.20 - 0.30 mm and a film thickness of 0.20 - 0.30 μm;

[0040] The temperature - rising program is: the initial temperature is 80 - 120 °C, hold for 0.3 - 1.0 minute, then rise to 260 - 300 °C at a rate of 8 - 12 °C / min and hold for 3 - 7 minutes;

[0041] The inlet temperature is 250 - 290 °C, and the injection volume is 0.5 - 1.5 μL.

[0042] Further, the mass spectrometry conditions include:

[0043] The ionization mode is EI, the ion source temperature is 210 - 250 °C, and the ionization energy is 60 - 80 eV;

[0044] The solvent delay time is 3 - 5 minutes, and the scan mode is SIM mode.

[0045] Further, the establishment of the standard curve linear equation includes:

[0046] Prepare standard working solutions of 6 isomers of karanaldehyde with a concentration range of 0.05 - 50.0 mg / L. After detecting by a gas chromatography - mass spectrometer, perform linear fitting with the concentration as the abscissa and the quantitative ion peak area as the ordinate;

[0047] Further, the solvent of the standard working solution is a mixed solvent of petroleum ether and chloroform with a volume ratio of 1:1.

[0048] Further, the detection limit of the method is 0.3 - 0.6 μg / L, the total detection time ≤ 35 minutes / sample, and the precision RSD ≤ 1.5%.

[0049] To facilitate the further understanding of the present invention by those skilled in the art, the present invention will be further elaborated below in combination with specific implementation cases.

[0050] A method for detecting the content of kala flower aldehyde in water quality based on gas chromatography - mass spectrometry includes sample pretreatment, sample detection, establishment of the standard curve linear equation, result calculation and expression. The steps of sample pretreatment and sample detection include:

[0051] A. Transfer the water sample to a separating funnel, add the extraction agent, shake for 10 min, let it stand for 3 min to separate layers, collect the extract, repeat the extraction multiple times, and combine the extracts;

[0052] B. The extract is dehydrated by a dehydrating agent, then concentrated by nitrogen blowing, fixed with a solvent, and the kala flower aldehyde in the sample is detected by a gas chromatography - mass spectrometer.

[0053] Gas chromatography conditions:

[0054] Chromatographic column: SH - I - 5MS capillary column or equivalent chromatographic column, 30 m × 0.25 mm (inner diameter), 0.25 μm;

[0055] The temperature - rising program is:

[0056] The initial temperature is 100 °C, hold for 0.5 min, increase the temperature to 280 °C at a rate of 10 °C / min, and hold for 5 min;

[0057] Injection port temperature: 270 °C;

[0058] Injection mode: splitless;

[0059] Injection volume: 1 μL;

[0060] Mass spectrometry conditions:

[0061] Ionization mode: EI;

[0062] Ion source temperature: 230 °C;

[0063] Ionization energy: 70 ev;

[0064] Solvent delay: 4 min;

[0065] Scanning mode of mass spectrometry conditions: SIM mode.

[0066] The specific extraction experiment is as follows:

[0067] Measure 100.0 mL of the water sample into a separatory funnel, add 15 mL of the extractant, shake vigorously for 10 min, and let it stand for 3 min to separate layers; repeat the extraction twice, combine the extractants and further filter and dehydrate. Place a layer of filter membrane on the funnel, add 5 g of anhydrous sodium sulfate as the dehydrating agent, and transfer the organic phase to a collecting bottle. Concentrate it to 1 mL by nitrogen blowing and then perform on-machine detection.

[0068] Ten different extractants were used to conduct extraction experiments according to the above method respectively, and the experimental results are shown in Tables 1 - 10.

[0069] Table 1 Petroleum ether extraction experiment:

[0070] Petroleum ether extraction Karahanaenal Response value 2.9578 Spiked concentration (4 mg / L) 4 Spiked recovery rate, % 73.95％

[0071] Table 2 Chloroform extraction experiment:

[0072] Chloroform extraction Karahanaenal Response value 2.8666 Spiked concentration (4 mg / L) 4 Spiked recovery rate, % 71.7％

[0073] Table 3 Ether extraction experiment:

[0074] Diethyl ether extraction Karahanaenal Response value 1.2875 Spiked concentration (4 mg / L) 4 Spiked recovery rate, % 32.2％

[0075] Table 4 Acetone extraction experiment:

[0076]

[0077]

[0078] Table 5 Cyclohexane extraction experiment:

[0079] Cyclohexane extraction Karahanaenal Response value 1.9642 Spiked concentration (4 mg / L) 4 Spiked recovery rate (%) 49.1％

[0080] Table 6 Dichloromethane extraction experiment:

[0081] Dichloromethane extraction Karahanaenal Response value 2.6643 Spiked concentration (4 mg / L) 4 Spiked recovery rate, % 66.6％

[0082] Table 7 Ethyl acetate extraction experiment:

[0083] Ethyl acetate extraction Karahanaenal Response value 1.7850 Spiked concentration (4 mg / L) 4 Spiked recovery rate, % 44.6％

[0084] Table 8 Benzene extraction experiment:

[0085] Benzene extraction Karahanaenal Response value 2.3430 Spiked concentration (4 mg / L) 4 Spiked recovery rate, % 58.6％

[0086] Table 9 Toluene extraction experiment:

[0087] Toluene extraction Karahanaenal Response value 2.4941 Spiked concentration (4 mg / L) 4 Spiked recovery rate, % 62.4％

[0088] Table 10 n - Hexane extraction experiment:

[0089] n-Hexane extraction Karahanaenal Response value 3.0578 Spiked concentration (4 mg / L) 4 Spiked recovery rate, % 76.4％

[0090] From the above experimental results, the three solvents with the highest spike recovery rates are petroleum ether at 73.9%, chloroform at 71.7%, and n-hexane at 76.4%. The three solvents with the highest recovery rates, petroleum ether, chloroform, and n-hexane, were used to conduct three groups of extraction experiments again according to the volume ratio of 1:1 using the same experimental method. The experimental results are shown in Tables 11 - 13.

[0091] Table 11 is the extraction experiment of petroleum ether:n-hexane;

[0092] Petroleum ether, n-hexane Karahanaenal Response value 2.8861 Spiked concentration (4 mg / L) 4 Spiked recovery rate, % 72.2％

[0093] Table 12 is the extraction experiment of petroleum ether:chloroform;

[0094] Petroleum ether, chloroform Karahanaenal Response value 3.6872 Spiked concentration (4 mg / L) 4 Spiked recovery rate, % 92.2％

[0095] Table 13 is the extraction experiment of n-hexane:chloroform;

[0096] n-Hexane, chloroform Karahanaenal Response value 3.2919 Spiked concentration (4 mg / L) 4 Spiked recovery rate, % 82.3％

[0097] From the above experimental results, the one with the highest spike recovery rate is petroleum ether:chloroform (1:1), with a recovery rate of 92.2%.

[0098] The present invention selected petroleum ether:chloroform (1:1) and further conducted three groups of experiments for 1, 2, and 3 extractions. The experimental results are shown in Tables 14 - 16.

[0099] Experimental results of 1 extraction in Table 14:

[0100] Extraction once Karahanaenal Response value 3.0950 Spiked concentration (4 mg / L) 4 Spiked recovery rate, % 77.4％

[0101] Experimental results of 2 extractions in Table 15:

[0102] Extraction twice Karahanaenal Response value 3.2973 Spiked concentration (4 mg / L) 4 Spiked recovery rate, % 82.4％

[0103] Experimental results of 3 extractions in Table 16:

[0104]

[0105]

[0106] When the recovery rate of petroleum ether:chloroform (1:1) for 3 extractions is the highest, which is 92.2%.

[0107] Case 1:

[0108] For the preparation of the standard working curve, petroleum ether: chloroform with a volume ratio of 1:1 was selected as the solvent. A standard stock solution with a concentration of 100 mg / L for each of the 6 isomers of karanjal was prepared. The standard stock solution was diluted with the above solvent to obtain standard working solutions with concentrations ranging from 0.1 mg / L to 30.0 mg / L.

[0109] 100 mg / L of the standard stock solution was respectively taken and diluted to standard working solutions of karanjal with concentrations of 0.1 mg / L, 0.2 mg / L, 1.0 mg / L, 2.0 mg / L, 5.0 mg / L, 10.0 mg / L, 20.0 mg / L, and 30.0 mg / L. 1 μL was accurately pipetted and injected into the gas chromatography - mass spectrometer for analysis, and the experiment was carried out according to the above chromatographic - mass spectrometric detection conditions. The standard working curve was plotted with the concentration of the standard substance as the abscissa and the peak area as the ordinate.

[0110] Figure 1 It shows that the linear range is 0.1 - 30.0 μg / L, meeting the requirement of 0.999.

[0111] Case 2:

[0112] A. 100.0 mL of the water sample was transferred to a separatory funnel, 15 mL of petroleum ether: chloroform with a volume ratio of 1:1 was added as the extractant, shaken for 10 min, allowed to stand for 3 min for layering, the extract was collected, and the extraction was repeated twice, and the extracts were combined;

[0113] B. The extract was dehydrated through a filter column of anhydrous sodium sulfate, the filtrate was collected, then concentrated by nitrogen blowing, and fixed to 1.0 mL with petroleum ether: chloroform (1:1), and then the karanjal in the sample was detected by a gas chromatography - mass spectrometer.

[0114] The experiment was carried out according to the chromatographic - mass spectrometric detection conditions in Case 1.

[0115] The sample detection results are as Figure 2 shown. The retention times of the 6 isomers of karanjal are 11.347 - 12.420 min.

[0116] According to the standard curve linear equation of karanjal obtained in Case 1, the content of karanjal in the sample was calculated, and then substituted into the following equation:

[0117] W = C × V 定 / V 取；

[0118] Among them, W: the content of karanjal in the sample, mg / kg;

[0119] C: the sum of the concentrations of the 6 isomers of karanjal obtained from the standard curve linear equation, mg / L;

[0120] V 定 : The constant volume of the sample, mL;

[0121] V 取 : The aliquot volume of the sample, mL.

[0122] Case 3:

[0123] This example is further optimized on the basis of Case 2:

[0124] Detection limit experiment: Referring to HJ168, the sample addition method was adopted, and parallel determinations were carried out 7 times to calculate the detection limit; the detection limit was 0.414 μg / L, as shown in Table 17.

[0125] Table 17 Detection limit experiment:

[0126]

[0127]

[0128] Precision and trueness experiments: Referring to HJ168, according to the low, medium, and high spike addition methods, parallel determinations were carried out 6 times to calculate the precision and trueness.

[0129] Table 18 shows that the relative standard deviations corresponding to the low, medium, and high concentrations of furaneol are 0.87%, 1.11%, and 0.82% respectively, and the truenesses are 92.8%, 95.2%, and 94.2% respectively.

[0130] Table 18 Precision and trueness experiments:

[0131] Karahanaenal 4.5 μg / L 18 μg / L 63 μg / L 1 4.1762 16.9356 60.2909 2 4.2362 17.4369 59.1841 3 4.1431 17.0410 59.2228 4 4.1808 17.1439 58.8910 5 4.1852 17.2587 59.4153 6 4.1343 16.9697 59.1752 Average value, μg / L 4.1760 17.1310 59.3632 Standard deviation, μg / L 0.0362 0.1910 0.4844 Relative standard deviation RSD % 0.87 1.11 0.82 Recovery rate, % 92.8 95.2 94.2

[0132] Case 4:

[0133] A. Pipette 100.0 mL of the water sample into a separatory funnel, add 15.0 mL of petroleum ether: chloroform with a volume ratio of 1:

[0134] 1 as the extractant, shake vigorously for 10 min, let stand for 3 min, and then repeat this operation 3 times to combine the extractants;

[0135] B. Filter through an anhydrous sodium sulfate filter column, collect the filtrate, concentrate it to 1.0 mL by nitrogen blowing, and detect furaneol in the sample using a gas chromatography - mass spectrometer.

[0136] Case 5:

[0137] This case is basically the same as Case 2, the difference is:

[0138]

[0139] ​In this case, a low-toxic solvent, ethyl acetate, was selected and mixed with n-hexane at a ratio of 1:1. At the same time, the extraction times were increased to 4 times to compensate for the difference in solvent polarity, and the chromatographic column temperature program was slightly adjusted: the initial temperature was 80°C.

[0140] Transfer 100.0 mL of the water sample to a separating funnel, and add 15 mL of the ethyl acetate:n-hexane (1:1) mixed solvent.

[0141] Oscillate for 10 minutes, let stand for 3 minutes to separate layers, and collect the extract; repeat the extraction 3 times and combine the extracts.

[0142] Filter the extract through an anhydrous sodium sulfate dehydration column and collect the filtrate.

[0143] Concentrate by nitrogen blowing to 1.0 mL (temperature 40°C, nitrogen flow rate 1.2 L / min).

[0144] Chromatographic column: equivalent SH-I-5MS capillary column (30 m × 0.25 mm, film thickness 0.25 μm).

[0145] Temperature program: initial temperature 80°C, hold for 0.5 minute, increase the temperature to 280°C at a rate of 10°C / min, and hold for 5 minutes.

[0146] Injector temperature: 270°C, injection volume 1 μL, splitless mode.

[0147] Ionization mode: EI, ion source temperature 230°C, ionization energy 70 eV. Solvent delay 4 minutes, SIM scan mode.

[0148] Six parallel tests were carried out as follows:

[0149]

[0150]

[0151] Determined by GC-MS headspace analysis, the VOC emissions were reduced by 60%; the risk of operators contacting toxic solvents was significantly reduced; in this case, on the premise that the recovery rate only decreased slightly (2.5%), the toxicity and environmental hazards were greatly reduced, and by increasing the extraction times and optimizing the temperature program, the efficiency loss caused by the difference in solvent polarity was compensated.

[0152] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0153] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. It should be noted that any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for detecting the content of karanaldehyde in water quality based on gas chromatography-mass spectrometry, comprising sample pretreatment, sample detection, establishment of a standard curve linear equation, and result calculation, characterized in that: The sample pretreatment includes the following steps: A. Transfer the water sample to a separatory funnel, add the extractant, shake for 8 - 12 minutes, let stand for 2 - 4 minutes to separate layers, collect the extract and repeat extraction 2 - 4 times, and combine the extracts; B. Dehydrate the extract with a dehydrating agent and then concentrate it by nitrogen blowing, dilute it to 0.5 - 2.0 mL with a solvent, and detect it using a gas chromatography - mass spectrometer.

2. The method for detecting the content of furanocoumarin in water quality based on gas chromatography - mass spectrometry according to claim 1, wherein: The extractant and the solvent are a mixed solvent of petroleum ether and chloroform, and the volume ratio of the two is 1:

1.

3. The method for detecting the content of furan carbaldehyde in water quality based on gas chromatography - mass spectrometry according to claim 1, wherein: In step A, the volume of the water sample transferred is 80 - 120 mL, and the amount of the extractant used each time is 10 - 20 mL.

4. The method for detecting the content of furan in water quality based on gas phase mass spectrometry according to claim 1, characterized in that: The dehydrating agent is anhydrous sodium sulfate.

5. A method for detecting the content of kalaheal in water quality based on gas chromatography - mass spectrometry according to claim 1, characterized in that, The gas chromatography conditions include: The chromatographic column is an SH - I - 5MS capillary column or an equivalent chromatographic column, with an inner diameter of 25 - 35 m×0.20 - 0.30 mm and a film thickness of 0.20 - 0.30 μm; The temperature - rising program is that the initial temperature is 80 - 120 °C, hold for 0.3 - 1.0 minute, increase the temperature to 260 - 300 °C at a rate of 8 - 12 °C / min, and hold for 3 - 7 minutes; The inlet temperature is 250 - 290 °C, and the injection volume is 0.5 - 1.5 μL.

6. The method for detecting the content of furan carbaldehyde in water quality based on gas chromatography - mass spectrometry according to claim 1, characterized in that, The mass spectrometry conditions include: The ionization mode is EI, the ion source temperature is 210 - 250 °C, and the ionization energy is 60 - 80 eV; The solvent delay time is 3 - 5 minutes, and the scanning mode is the SIM mode.

7. A method for detecting the content of kalaheal in water quality based on gas chromatography-mass spectrometry according to claim 1, characterized in that, The establishment of the standard curve linear equation includes: Prepare standard working solutions of 6 isomers of furanone, with a concentration range of 0.05 - 50.0 mg / L. After detection by a gas chromatography - mass spectrometer, perform linear fitting with the concentration as the abscissa and the quantitative ion peak area as the ordinate.

8. A method for detecting the content of kalaheal in water quality based on gas chromatography - mass spectrometry according to claim 7, characterized in that: The solvent of the standard working solution is a mixed solvent of petroleum ether and chloroform with a volume ratio of 1:

1.

9. A method for detecting the content of karanaldehyde in water quality based on gas chromatography - mass spectrometry according to claim 8, characterized in that: The detection limit of the method is 0.3 - 0.6 μg / L, the total detection time ≤ 35 minutes / sample, and the precision RSD ≤ 1.5%.

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