Amine compound content detection method

Abstract

The invention belongs to the technical field of automobile material detection, and discloses a method for detecting the content of amine compounds, which comprises the following steps: preparing a sampling tube: putting glass wool into a round-bottom flask, adding a phosphoric acid acetonitrile solution, spin-drying by a rotary evaporator, and filling the glass wool into a glass dropper to prepare the sampling tube; sample collection: sampling the pretreated whole vehicle sample and / or assembly sample by using a sampling tube; eluting a sample, namely eluting for multiple times by using a formic acid-methanol aqueous solution after sampling, and putting an eluent into a volumetric flask for constant volume for later use; and the sample is determined by LC-MS. According to the method, the sampling tube is prepared to enable the amine compounds to react with phosphoric acid, formic acid is used for elution, the sample solution is analyzed through LC-MS equipment, accurate qualitative and quantitative analysis of the common amine compounds in the automobile materials is achieved, a reliable analysis rear section is provided, the precision of the analysis method reaches 10% or below, and operation is stronger and more convenient; the recovery rate of the sampling tube reaches more than 80%.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of automobile material detection, and particularly relates to an amine compound content detection method. BACKGROUND

[0002] Amine is an organic compound containing nitrogen atoms, and its taste is usually irritating. When amine compounds volatilize, people can smell a specific odor, often described as ammonia smell, fishy smell. Amine compounds are mainly related to the problem of peculiar smell in the automobile industry, especially in non-metallic parts containing foam materials such as seats and door panels. The residue may cause annoying odors such as ammonia odor and fishy odor, directly affecting the air quality and consumer experience in the car.

[0003] At present, the reported detection methods of trimethylamine include spectrophotometry, headspace gas chromatography, headspace gas chromatography-mass spectrometry, ion chromatography, sensor method, capillary electrophoresis method, etc., but all have their own limitations. Gas chromatography is the most widely used method.

[0004] Taking trimethylamine as an example, the standard “Air Quality Determination of Trimethylamine Gas Chromatography” (GB / T 14676-1993) specifies the gas chromatography method for determining trimethylamine in environmental air, odor fixed pollution sources organized and unorganized emissions. The method uses oxalic acid-coated glass beads as an adsorbent, which is packed in a sampling tube for collecting trimethylamine in odor pollution source exhaust and plant boundary environmental air. By injecting saturated sodium hydroxide solution and nitrogen into the sampling tube, the collected trimethylamine is freed into a gaseous state, and then determined by packed column gas chromatography.

[0005] In addition, “Determination of Toxic Substances in the Workplace Air Part 136: Trimethylamine, Diethylamine and Triethylamine” (GBZ / T 300.136-2017) also introduces a gas chromatography method for determining the above amine compounds. The method first collects the vapor state trimethylamine, diethylamine and triethylamine in the air with basic silica gel, then desorbs with sulfuric acid solution, and then samples, detects by hydrogen flame ionization detector, and finally qualitatively determines by retention time and quantitatively determines by peak height or peak area.

[0006] The Chinese invention patent with the publication number CN115993414A discloses a method for determining amine compounds in automobile non-metallic materials, including two analysis methods of GCMS and LC-MS. When primary and secondary amine compounds are tested by the LC-MS method, they need to be first derivatized by methylbenzoyl chloride and sodium hydroxide solution. The derivatization process of this method is relatively complex, and the analysis of odor problems in the air quality in the vehicle has certain limitations when the GC-MS method is used. Because Tenax tube is used for sampling, some amine compounds represented by dimethylamine and trimethylamine cannot be collected, and the collection amount of other amine compounds is also low. However, amine compounds have a low odor threshold and can emit a special odor at very low concentrations, so their impact on the user's experience in the vehicle cannot be ignored. The existing amine analysis method is mainly aimed at aliphatic and aromatic amine compounds, and the analysis method for amine compounds in automobile interior materials is relatively blank, so it is necessary to develop an analysis method for amine compounds in automobile interior materials to deal with the odor impact of amine compounds during use. SUMMARY

[0007] The purpose of the present application is to provide a method for detecting the content of amine compounds. The present application prepares a sampling tube suitable for amine compounds, reacts the amine compounds with phosphoric acid, and then elutes them with formic acid without derivatization, making the test simpler. The amine compound analysis method of the present application analyzes the obtained amine compound solution in combination with existing LC-MS equipment, enabling accurate quantitative determination of several common amine compounds in automobile materials, providing a reliable analysis back-end for subsequent control of the adverse effects of amine compounds. The precision of the analysis method is within 10%, and the operability is stronger and more convenient. The recovery rate of the sampling tube is more than 80%.

[0008] The specific scheme content is as follows:

[0009] A method for detecting the content of amine compounds, comprising the following steps:

[0010] S1, preparing a sampling tube: take an appropriate amount of glass wool into a round-bottom flask, add phosphoric acid acetonitrile solution, and dry it with a rotary evaporator. Take an appropriate amount of dried glass wool and fill it into a glass dropper to make a sampling tube. Then seal the two ends of the sampling tube, and store the sealed sampling tube in a refrigerator.

[0011] S2, sample collection: use the sampling tube that is left to room temperature to sample the pretreated whole vehicle sample and / or assembly sample.

[0012] S3, sample elution: immediately elute the sampling tube with formic acid methanol water solution after sampling, and then put the eluent into a volumetric flask and finally make up to volume.

[0013] S4, determine the sample by LC-MS.

[0014] Further, in step S1, the phosphoric acid acetonitrile solution is dried by rotary evaporation at 60-100 r / min and 40-80°C; and the refrigeration temperature of the sealed sampling tube is 4°C.

[0015] Further, in step S2, the whole vehicle sample is collected, and after pretreatment, the sampling volume is 20-160 L.

[0016] Further, in step S2, the assembly sample is collected, and the sample wrapped with tin paper and PE film is pretreated first. During pretreatment, the test sample is placed on a shelf, and the samples are prevented from contacting each other and other objects outside the shelf. After pretreatment, the sample is unpacked, placed in a sampling bag, and subjected to three times of aeration. After aeration, 50% nitrogen is filled, and the assembly sample is heated at 65°C for 2 hours. Then, the sample is taken out of the sampling cabin, placed in a room temperature environment, and connected to a sampling tube for sampling. The sampling volume is 20-80 L.

[0017] Further, in step S3, the volume ratio of the formic acid methanol aqueous solution is methanol: water: formic acid = 1:1:0.2.

[0018] Further, the chromatographic analysis conditions of step S4 are as follows: the chromatographic column is InfinityLab Poroshell 120 Aq-C18, 3.0*150mm 2.7-Micron, the column temperature is 40°C, the flow rate is 0.4 mL / min, the injection volume is 1 μL, the mobile phase is 0.1% formic acid aqueous solution and methanol, the volume ratio is 0.1% formic acid water: methanol = 1:1, gradient elution or isocratic elution is used, and the mass spectrometry analysis conditions are as follows: the desolvation gas temperature is 350°C, the desolvation gas flow rate is 1000 L / h, the capillary voltage is 3kV, the cone gas flow rate is 50 L / h, and the cone voltage is the optimal cone voltage of the target amine compound.

[0019] Further, the column temperature of the chromatographic column is 30°C.

[0020] Further, THF is added to the mobile phase of 0.1% formic acid aqueous solution and methanol for gradient elution.

[0021] Further, the gradient elution scheme of the mobile phase of 0.1% formic acid aqueous solution and methanol with a volume ratio of 0.1% formic acid water: methanol = 1:1 to which THF is added is optimized as follows: the addition time of THF is advanced to 0.5 min, the proportion is increased to 5%, and the flow rate of the mobile phase is changed from 0.5 ml / min to 0.3 ml / min.

[0022] Further, the target amine compound includes: dimethylamine, trimethylamine, triethylamine, pyridine, morpholine, aniline, 2,4-diaminotoluene and the like, and the optimal orifice voltage of each amine compound is: the optimal orifice voltage of each amine compound: the optimal orifice voltage of each amine compound: the orifice voltage of dimethylamine with a mass-to-charge ratio of 46.03 is 42kV, the orifice voltage of trimethylamine with a mass-to-charge ratio of 60.08 is 40kV, the orifice voltage of triethylamine with a mass-to-charge ratio of 102.2 is 45kV, the orifice voltage of pyridine with a mass-to-charge ratio of 80.1 is 40kV, the orifice voltage of morpholine with a mass-to-charge ratio of 88.07 is 41kV, the orifice voltage of aniline with a mass-to-charge ratio of 90.1 is 43kV, and the orifice voltage of 2,4-diaminotoluene with a mass-to-charge ratio of 123.09 is 35kV.

[0023] Compared with the prior art, the present application has the following beneficial effects:

[0024] 1. The sampling tube prepared by the present application is reacted with amine compounds and phosphoric acid, and then eluted by formic acid, without derivation, so that the test is simpler;

[0025] 2. The present application provides LC-MS analysis conditions and measurable amine substances by combining with existing LCMS equipment, so as to realize accurate qualitative and quantitative analysis of several common amine substances in automobile materials;

[0026] 3. The present application can solve the separation difficulty, insufficient sensitivity and complex pretreatment of GC-MS analysis of short-chain amine, and realize the analysis of trimethylamine, dimethylamine and other substances in common amine substances, which is more operable and convenient;

[0027] 4. The precision of the analysis method of the present application is within 10%, which provides a reliable analysis back stage for subsequent control of the adverse effects of amine compounds;

[0028] 5. The recovery rate of the sampling tube of the present application is more than 80%. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 LC-MS analysis chromatogram and mass spectrum diagram of morpholine in Example 2.

[0030] Figure 2 LC-MS analysis chromatogram and mass spectrum diagram of pyridine in Example 2.

[0031] Figure 3 Trimethylamine standard curve diagram of Example 3.

[0032] Figure 4 Aniline standard curve of Example 4.

[0033] Figure 5Standard curve for dimethylamine for Example 5.

[0034] Figure 6 Peak time plot for dimethylamine standard for Example 5.

[0035] Figure 7 Analysis results and chromatogram for seat sample 1 for Example 5.

[0036] Figure 8 Analysis results and chromatogram for seat sample 2 for Example 5.

[0037] Figure 9 Standard curve plot for 2,4-diaminotoluene for Example 6.

[0038] Figure 10 Chromatogram for 2,4-diaminotoluene for Example 6.

[0039] Figure 11 Chromatogram for 0.00625 mg / L triethylamine solution with eluent volume ratio of methanol / water / formic acid = 1 / 1 / 0.2 for Example 7.

[0040] Figure 12 Chromatogram for 0.00625 mg / L triethylamine solution with eluent volume ratio of methanol / water / formic acid = 1 / 1 / 0.05 for Example 7.

[0041] Figure 13 Chromatogram for isocratic elution separation scheme with mobile phase of 0.1% formic acid in water / methanol system for Example 8.

[0042] Figure 14 Chromatogram for gradient elution separation scheme with mobile phase of 0.1% formic acid in water / methanol system with THF addition for Example 8.

[0043] Figure 15 Chromatogram for optimized gradient elution scheme with mobile phase of THF / 0.1% formic acid in water / methanol system for Example 9.

[0044] Figure 16 Separation effect plot for trimethylamine and 2,4-diaminotoluene with column temperature of 40°C for Example 10.

[0045] Figure 17 Detection content plot for 0.00625 mg / L triethylamine solution with cone voltage of 109 V and 45 V for Example 11. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0047] The present application provides a kind of amine compound content detection method, by preparing a kind of sampling tube suitable for amine compound, make amine compound and phosphoric acid reaction, again using formic acid to it is eluted, finally with LC-MS to obtain amine compound solution is analyzed, when using LC-MS method test in primary amine and secondary amine, it is not necessary to be derived first through methyl benzoyl chloride and sodium hydroxide solution, solve the problem that amine compound is not easy to sample;Again in combination with existing LC-MS equipment, the amine compound analysis method of the present application is developed, realizes the accurate nature of several common amine compounds in automobile material, quantitative, for subsequent amine compound adverse effect control provides a reliable analysis rear section.And sampling tube recovery can reach more than 80%, LC-MS analysis method precision reaches within 10%.

[0048] The amine compound content detection method of the present application, steps include:

[0049] S1, preparation sampling tube: take appropriate glass wool into round bottom flask, add phosphoric acid acetonitrile solution, use rotary evaporator to spin dry, take appropriate glass wool after spin dry to fill in glass dropper to make sampling tube, again seal the two ends of sampling tube, the sealed sampling tube is stored in cold storage;

[0050] S2, sample collection: using sampling tube at room temperature to sample the pretreated whole vehicle sample and / or assembly sample;

[0051] S3, sample elution: immediately wash the sampling tube after sampling through formic acid methanol aqueous solution for multiple times, eluent is placed in volumetric flask, finally constant volume is used.

[0052] S4, LC-MS is used to determine the sample.

[0053] In step S1, when preparing the sampling tube, appropriate glass wool is placed in a round bottom flask, phosphoric acid acetonitrile solution is added, and a rotary evaporator is used to spin dry under the condition of 60-100 r / min and 40-80 DEG C. Appropriate glass wool after spin dry is filled into a glass dropper to make a sampling tube, and the two ends of the sampling tube are sealed with a spray gun or a copper cap. The sealed sampling tube is stored in a refrigerator at 4 DEG C for cold storage, and is taken out and placed at room temperature before use. The effective period of the sampling tube is 6 months.

[0054] In step S2, for the whole vehicle sample, according to the pretreatment and sampling requirements in HJ / T 400-2007, the sampling tube conditions are in accordance with the requirements of the DNPH sampling tube, the sampling volume is 20-160 L, and the sampling volume is 20-160 L because the content of amine substances is low, and the sampling volume needs to be increased to ensure that it can be collected.

[0055] In step S2, the assembly sample is collected, the sample is packaged with tin paper and PE film, and then pretreated at constant temperature and humidity, and the pretreated sample is placed in a standard environment (23±2) ℃, (50±10) % RH) for more than 24 h according to the standard environment in GB / T 2918. The test sample should be placed on a shelf or grid, and the samples should not contact each other, and the samples should not contact other objects outside the shelf or grid. After pretreatment, the sample is taken out of the package and placed in a 2000 L PVF sampling bag, and three times of air charging and air exchange are performed, and the operation is the same as the VOC bag method assembly sampling requirement. After air exchange, 50% nitrogen is filled, and heating at 65℃±2℃ for 2 hours is performed, and after heating, the sampling tube is connected for sampling, and the sampling volume is 20-80 L.

[0056] In the sampling process, because the boiling point of amine compounds is low, in order to avoid loss during sampling, the assembly sample is heated at 65℃ for 2 hours, then taken out of the sampling cabin and placed in a room temperature environment for sample collection. The integral peak area and corresponding intensity of the sample collected at room temperature are greatly improved compared with the integral peak area and response intensity of the sample collected at high temperature.

[0057] In step S3, the volume ratio of the methanol-water-formic acid solution is methanol: water: formic acid = 1: 1: 0.2.

[0058] The amount of formic acid added has a significant effect on the elution of target substances. If the volume ratio of the methanol-water-formic acid solution does not meet the technical solution of the present application, i.e. methanol: water: formic acid = 1: 1: 0.2, the target substance cannot be completely eluted, the chromatographic peak area is greatly reduced, and the elution amount of amine compounds is below the detection limit.

[0059] In step S4, the analysis was performed using LC-MS in positive ion mode. The chromatographic conditions were as follows: InfinityLab Poroshell 120 Aq-C18 column, 3.0*150mm 2.7-Micron, column temperature 40℃, flow rate 0.4mL / min, injection volume 1μL, mobile phase 0.1% formic acid aqueous solution and methanol, volume ratio 0.1% formic acid aqueous solution: methanol = 1:1, gradient elution or isocratic elution was used. The mass spectrometry conditions were as follows: desolvation temperature 350℃, desolvation gas flow 1000L / h, capillary voltage 3kV, cone gas flow 50L / h, and the cone voltage was the optimal cone voltage for the target amine compound.

[0060] The detection and separation of amines were performed using an InfinityLab Poroshell 120 Aq-C18 column (3.0 x 150 mm, 2.7-Micron). The InfinityLab Poroshell 120 column features a very smooth core surface and uniform particle size, resulting in a highly concentrated overall particle size distribution. This contributes to improved analytical performance and reproducibility, making it suitable for the separation of small molecule compounds.

[0061] THF was added to a mobile phase consisting of 0.1% formic acid aqueous solution and methanol in a volume ratio of 0.1% formic acid aqueous solution: methanol = 1:1, and gradient elution was employed.

[0062] Since small molecule amine fragments are similar and have concentrated retention times, in order to improve the separation between small molecule amines, an innovative scheme was developed to introduce THF (tetrahydrofuran) into a 0.1% formic acid aqueous solution / methanol isocratic elution system and perform gradient elution.

[0063] The gradient elution protocol with THF added, consisting of 0.1% formic acid aqueous solution and methanol in a volume ratio of 0.1% formic acid aqueous solution: methanol = 1:1, was optimized by advancing the THF addition time to 0.5 min, increasing the THF concentration to 5%, and changing the mobile phase flow rate from 0.5 ml / min to 0.3 ml / min. By reducing the flow rate, the retention time of the substances was increased, and the sample separation was significantly improved.

[0064] The column temperature was optimized to 30℃, which improved the separation effect.

[0065] The amine compound content detection method of the present application is used to analyze amine compounds including dimethylamine, trimethylamine, triethylamine, pyridine, morpholine, aniline, 2,4-diaminotoluene and other amine compounds, but not limited to the above amine compounds; the optimal cone voltage of each amine compound is shown in Table 1 amine compound test type and key parameters:

[0066]

[0067] After each amine compound is accurately quantified, the corresponding standard sample is diluted step by step to establish a curve, and the accurate quantitative result of the amine compound can be obtained, which is used for subsequent analysis.

[0068] The technical effects of the present application are described in detail as follows: Figures 1 to 17 The technical effects of the present application are described in detail as follows:

[0069] Example 1:

[0070] According to the technical scheme of the present application, 10 mg / m 3 of trimethylamine methanol solution 250 μl is added to two 10L gas bags, respectively, and placed at 65℃ for 2 h, then collected at a flow rate of 400 mL / min for 10 min under the original high temperature environment and normal temperature environment, respectively, and the results show that:

[0071] 1. The trimethylamine integral peak area of the sample collected at normal temperature (598057.125) is about 178% higher than that of the sample collected at high temperature (214976.484);

[0072] 2. The corresponding intensity of trimethylamine of the sample collected at normal temperature (1.57e7) is about 39% higher than that of the sample collected at high temperature (1.13e7).

[0073] Example 2:

[0074] According to the technical scheme of the present application, the sampling tube prepared by step S1 is used, the refrigerated sampling tube is taken out in advance and placed at room temperature, the total sample is collected, the sample is packaged with tin paper and PE film, and the sample is pretreated in a constant temperature and humidity environment for more than 24 h according to the standard environment specified in GB / T 2918 ((23±2) ℃, (50±10)% RH). The test sample should be placed on a shelf or grid, and the samples should not contact each other, and the samples should not contact other objects outside the shelf or grid. After the pretreated sample is taken out of the package, it is placed in a 2000L PVF sampling bag, and three times of air exchange is performed, which is the same as the VOC bag method total sampling requirement. After air exchange, 50% nitrogen is filled, and heating at 65℃±2℃ for 2 h is performed. After heating, the sampling tube is connected for sampling, and the sampling volume is 24L. The sampling tube is immediately washed with formic acid methanol water solution, i.e. the volume ratio of methanol: water: formic acid = 1:1:0.2, for 3-4 times, the eluent is placed in a volumetric flask, and finally 5mL is prepared for standby. Then the type of InfinityLab Poroshell 120 Aq-C18, 3.0*150mm 2.7-Micron chromatographic column is used for detection and separation of amine compounds, positive ion mode, and the chromatographic analysis conditions are as follows: the chromatographic column is InfinityLab Poroshell 120 Aq-C18, 3.0*150mm 2.7-Micron, the column temperature is 30℃, the flow rate is 0.4mL / min, the injection volume is 1μL, the elution gradient scheme of THF / 0.1% formic acid aqueous solution / methanol mobile phase system is used for elution, and the addition time of THF is advanced to 0.5min, the proportion is increased to 5%, and the flow rate of the mobile phase is changed from 0.5ml / min to 0.3ml / min; the mass spectrometry analysis conditions are as follows: desolvation temperature (Desolvation Temperature) 350 ℃, desolvation gas flow (Desolvation Gas Flow) 1000L / h, capillary voltage (Capillary) 3kV, cone gas flow (Cone Gas Flow) 50L / h, and the cone voltage is the optimal cone voltage of the target amine compound.

[0075] The morpholine and pyridine in the sample are analyzed, the chromatogram and mass spectrum of the morpholine analyzed by LC-MS are as shown in Figure 1 The chromatogram and mass spectrum of the pyridine analyzed by LC-MS are as shown in Figure 2 It can be proved that the amine compound content detection method of the present application can correctly detect the target amine compound, and realize the accurate determination of amine compounds.

[0076] Example 3:

[0077] The amine compound content detection method according to the present application uses LC-MS equipment to analyze trimethylamine in a sample, the chromatographic analysis conditions and the mass spectrometry analysis conditions are the same as those in Example 2, after trimethylamine is accurately quantified, corresponding standard samples are gradually diluted to establish a curve, and then accurate quantitative results of trimethylamine can be obtained, which are used for subsequent analysis, and the test results are as follows:

[0078] 1. According to the instrument parameters in the scheme, trimethylamine standard samples are gradually diluted, and the target concentration and the actual test results are as shown in Table 2:

[0079]

[0080] 2. According to the test results, a trimethylamine test curve is established as shown in Figure 3 , and the correlation coefficient r2 of the curve is 0.997.

[0081] Example 4:

[0082] The amine compound content detection method according to the present application uses LC-MS equipment to analyze aniline in a sample, the chromatographic analysis conditions and the mass spectrometry analysis conditions are the same as those in Example 2, after aniline is accurately quantified, corresponding standard samples are gradually diluted to establish a curve, and then accurate quantitative results of aniline can be obtained, which are used for subsequent analysis, and the test results are as follows:

[0083] 1. According to the instrument parameters in the scheme, aniline standard samples are gradually diluted, and the target concentration and the actual test results are as shown in Table 3:

[0084]

[0085] 2. According to the test results, an aniline test curve is established as shown in Figure 4 , and the correlation coefficient r 2 of the curve is 0.999.

[0086] Example 5:

[0087] The amine compound content detection method according to the present application uses LC-MS equipment to analyze dimethylamine in a sample, the chromatographic analysis conditions and the mass spectrometry analysis conditions are the same as those in Example 2, after dimethylamine is accurately quantified, corresponding standard samples are gradually diluted to establish a curve, and then accurate quantitative results of dimethylamine can be obtained, which are used for subsequent analysis, and the test results are as follows:

[0088] 1. According to the instrument parameters in the scheme, dimethylamine standard samples are gradually diluted, and the target concentration and the actual test results are as shown in Table 4:

[0089]

[0090] 2. According to the test results, a dimethylamine test curve is established as shown in Figure 5As shown, the curve correlation coefficient r2 is 0.998.

[0091] 3. According to the method, a set of parallel samples are tested for dimethylamine content using a seat assembly sample, and the analysis results and chromatogram are as follows: dimethylamine standard sample peak time is as shown in Figure 6 As shown, seat sample 1 is as shown in Figure 7 As shown, seat sample 2 is as shown in Figure 8 As shown.

[0092] Example 6:

[0093] According to the amine compound content detection method of the present application, LC-MS equipment is used to analyze 2,4-diaminotoluene in the sample, the chromatographic analysis conditions and mass spectrometry conditions are the same as in Example 2, after the accurate quantification of 2,4-diaminotoluene, the corresponding standard sample is diluted step by step, a curve is established, and the accurate quantitative result of 2,4-diaminotoluene is obtained, which is used for subsequent analysis, and the test results are as follows:

[0094] 1. According to the instrument parameters in the scheme, 2,4-diaminotoluene standard samples are diluted step by step, and the target concentration and actual test results are as shown in Table 5:

[0095]

[0096] 2. According to the test results, the 2,4-diaminotoluene test curve is as shown in Figure 9 , and the chromatogram Figure 10 , the curve correlation coefficient r 2 is 0.998.

[0097] 3. The precision of the method for testing 2,4-diaminotoluene is calculated as follows:

[0098]

[0099] According to the above data, it is calculated that the precision of the method for testing 2,4-diaminotoluene is 7.1%.

[0100] Example 7:

[0101] The eluent with a volume ratio of methanol / water / formic acid=1 / 1 / 0.2 and the eluent with a volume ratio of methanol / water / formic acid=1 / 1 / 0.05 and the sample with a triethylamine content of 0.00625mg / L are used for elution, and the test results are shown in Figure 11 0.00625mg / L triethylamine solution detection chromatogram (eluent volume ratio is methanol / water / formic acid=1 / 1 / 0.2), Figure 120.00625mg / L triethylamine solution test chromatogram (eluent volume ratio of methanol / water / formic acid = 1 / 1 / 0.05) shows that the amount of formic acid has a significant effect on the elution of the target amine compounds in the sampling tube:

[0102] 1. When the eluent volume ratio is methanol / water / formic acid = 1 / 1 / 0.2, the detection content is 0.00436mg / L.

[0103] 2. When the eluent volume ratio is methanol / water / formic acid = 1 / 1 / 0.05, the target amine compounds cannot be completely eluted, the chromatographic peak area is reduced by 70.6%, and the triethylamine elution amount is below the detection limit.

[0104] Example 8:

[0105] The LC-MS device of the present application is used to analyze the mixed standard sample, in positive ion mode, and the mass spectrometry conditions are the same as those of Example 2. The other conditions of the chromatographic analysis conditions are the same as those of Example 2. THF (tetrahydrofuran) is introduced into the mobile phase 0.1% formic acid aqueous solution / methanol isocratic elution system for gradient elution. Two groups of mixed standard samples eluted using the mobile phase 0.1% formic acid aqueous solution / methanol isocratic elution system and using THF introduced into the mobile phase 0.1% formic acid aqueous solution / methanol for gradient elution are tested, and the results are as follows:

[0106] The test results of using the mobile phase 0.1% formic acid aqueous solution / methanol isocratic elution system without introducing THF are shown in Table 6. Figure 13

[0107] After introducing THF, the mixed standard sample is gradient eluted according to the mobile phase parameters in Table 7 THF / 0.1% formic acid aqueous solution / methanol system gradient elution scheme, and the test results are shown in Table 8. Figure 14

[0108] Compared with each other, after introducing THF, the separation degree of pyridine and trimethylamine is increased from 0.46 to 1.6, the separation degree of pyridine and triethylamine is increased from 0.29 to 1.54, the separation degree of triethylamine and 2,4-diaminotoluene is increased from 0.13 to 0.71, the separation degree of triethylamine and trimethylamine is increased from 0.2 to 0.33, and the separation degree of trimethylamine and 2,4-diaminotoluene is increased from 0.33 to 0.48.

[0109]

[0110] It can be seen that the separation effect of gradient elution by adding THF to the mobile phase 0.1% formic acid aqueous solution / methanol eluent is better than that before adding THF.

[0111] Example 9: ​​

[0112] The LC-MS device of the present application was used to analyze the mixed standard sample, in positive ion mode, with the same mass spectrometry analysis conditions as in Example 2, and other conditions of the chromatography analysis conditions being the same as in Example 2. THF was added to the 0.1% formic acid aqueous solution / methanol mobile phase system and the gradient, ratio, and flow rate were adjusted. The mixed standard sample was gradient eluted according to the mobile phase parameters in the THF / 0.1% formic acid aqueous solution / methanol system gradient elution optimization scheme in Table 8. The obtained chromatogram is shown in Figure 15 ;

[0113] The THF / 0.1% formic acid aqueous solution / methanol system gradient elution optimization scheme was used for elution, and the analysis results were compared with those of the THF / 0.1% formic acid aqueous solution / methanol system gradient elution scheme without optimization in Example 8. After optimization, the separation degree of pyridine and trimethylamine was increased from 1.6 to 2.53, the separation degree of pyridine and triethylamine was increased from 1.54 to 2.44, the separation degree of triethylamine and 2,4-diaminotoluene was increased from 0.71 to 2.1, and the separation degree of triethylamine and trimethylamine was increased from 0.33 to 0.72; the separation degree of trimethylamine and 2,4-diaminotoluene was increased from 0.48 to 2, proving that the THF / 0.1% formic acid aqueous solution / methanol system gradient elution scheme after optimization significantly improved the separation effect.

[0114]

[0115] Example 10

[0116] The LC-MS device of the present application was used to analyze the mixed standard sample, in positive ion mode, with the same mass spectrometry analysis conditions as in Example 2, and other conditions of the chromatography analysis conditions being the same as in Example 2. The column temperature of the chromatographic column was increased to 40℃, and the separation effect of trimethylamine and 2,4-diaminotoluene is shown in Figure 16 , with a separation degree of 0.45. The column temperature of the chromatographic column in Example 9 was optimized to 30℃, and other conditions were the same as in Example 10. The separation degree of trimethylamine and 2,4-diaminotoluene in the analysis results of Example 9 was 2. Compared with Example 9, the separation degree of Example 10 decreased by 77.5%, proving that the separation effect is better when the column temperature of the chromatographic column is 30℃.

[0117] Example 11

[0118] The LC-MS device of the present application was used to analyze the sample, in positive ion mode, with the same chromatography analysis conditions as in Example 2, and other conditions of the mass spectrometry analysis conditions being the same as in Example 2. A 0.00625 mg / L triethylamine solution was analyzed under the conditions of a cone voltage of 109 V and 45 V, respectively, and the detection contents are shown in Figure 17 the 1st and 2nd rows as follows:

[0119] 1. When the cone hole voltage is 109 V, the target amine compound cannot be detected;

[0120] 2. When the cone hole voltage is 45 V, the detection concentration of the target amine compound is 0.00596 mg / L.

[0121] Example 12:

[0122] The sampling tube recovery rate is calculated, and details are shown in Table 9:

[0123]

[0124] It can be seen that the sampling tube recovery rate of the present application reaches more than 80%.

[0125] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for detecting an amine compound content, characterized by the steps of The method comprises the following steps: S1, preparing a sampling tube: a proper amount of glass wool is put into a round-bottom flask, a phosphoric acid acetonitrile solution is added, and a rotary evaporator is used to spin dry, a proper amount of the glass wool after spinning dry is filled into a glass dropper to make a sampling tube, and the two ends of the sampling tube are sealed, and the sealed sampling tube is stored in a refrigerator; S2, sample collection: the sampling tube at room temperature is used to sample the pretreated whole vehicle sample and / or assembly sample; S3, sample elution: the sample is eluted multiple times by a formic acid methanol water solution immediately after the sampling tube is sampled, the eluent is put into a volumetric flask, and finally, the volume is determined for standby; S4, the sample is determined by LC-MS.

2. The method for detecting the content of amine compounds according to claim 1, characterized by, In the step S1, the phosphoric acid acetonitrile solution is spin dried at 60-100 r / min and 40-80℃ by using a rotary evaporator; and the refrigeration temperature of the sealed sampling tube is 4℃.

3. The method for detecting the content of amine compounds according to claim 1, characterized in that, In the step S2, the whole vehicle sample is collected after being pretreated, and the sampling volume is 20-160 L.

4. The method for detecting the content of amine compounds according to claim 1, characterized in that, In the step S2, the assembly sample is collected, the sample wrapped with tin paper and PE film is pretreated first, during the pretreatment, the test sample is placed on a shelf, the samples are prevented from contacting each other, and the samples are also prevented from contacting other objects outside the shelf; After the pretreated sample is taken off the wrapping, it is put into a sampling bag, and three times of aeration is performed, 50% nitrogen is filled after aeration, the assembly sample is heated at 65℃ for 2 hours, then taken out from the sampling cabin, and placed in a room temperature environment to be connected to the sampling tube for sample collection, and the collection volume is 20-80 L.

5. The method for detecting the content of amine compounds according to claim 1, characterized in that, In the step S3, the volume ratio of the formic acid methanol water solution is methanol: water: formic acid = 1: 1: 0.

2.

6. The method of claim 1, wherein the amine compound is selected from the group consisting of: ###0002### In the step S4, the chromatographic analysis conditions are as follows: the chromatographic column is InfinityLab Poroshell 120 Aq-C18, 3.0*150mm 2.7-Micron, the column temperature is 40℃, the flow rate is 0.4mL / min, the injection volume is 1μL, the mobile phase is 0.1% formic acid aqueous solution and methanol, the volume ratio is 0.1% formic acid water: methanol = 1: 1, gradient elution or isocratic elution is adopted, and the mass spectrometry analysis conditions are as follows: the desolvation gas temperature is 350℃, the desolvation gas flow rate is 1000L / h, the capillary voltage is 3kV, the cone gas flow rate is 50L / h, and the cone voltage is the optimal cone voltage of the target amine compound.

7. The method according to claim 6, wherein The column temperature of the chromatographic column is 30℃.

8. The method according to claim 6, wherein The gradient elution is performed after THF is added to the mobile phase of 0.1% formic acid aqueous solution and methanol.

9. The method for detecting the content of amine compounds according to claim 6, characterized in that, The gradient elution scheme of the mobile phase of 0.1% formic acid aqueous solution and methanol with the volume ratio of 0.1% formic acid water: methanol = 1: 1 is optimized: the addition time of THF is advanced to 0.5min, the ratio is increased to 5%, and the flow rate of the mobile phase is changed from 0.5ml / min to 0.3ml / min.

10. The method for detecting the content of amine compounds according to claim 1, characterized in that, The target amine compounds include dimethylamine, trimethylamine, triethylamine, pyridine, morpholine, aniline, 2,4-diaminotoluene and the like, and the optimal orifice voltage of each amine compound is: the optimal orifice voltage of each amine compound is: the optimal orifice voltage of each amine compound is: the orifice voltage of dimethylamine with a mass-to-charge ratio of 46.03 is 42 kV, the orifice voltage of trimethylamine with a mass-to-charge ratio of 60.08 is 40 kV, the orifice voltage of triethylamine with a mass-to-charge ratio of 102.2 is 45 kV, the orifice voltage of pyridine with a mass-to-charge ratio of 80.1 is 40 kV, the orifice voltage of morpholine with a mass-to-charge ratio of 88.07 is 41 kV, the orifice voltage of aniline with a mass-to-charge ratio of 90.1 is 43 kV, and the orifice voltage of 2,4-diaminotoluene with a mass-to-charge ratio of 123.09 is 35 kV.

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