Determination method of (methyl) acrylic acid compounds in textiles

Abstract

The invention discloses a method for determining (methyl) acrylic compounds in textiles, which comprises the following steps: (1) accurately weighing a to-be-determined textile sample, putting the to-be-determined textile sample in a reactor, and adding an extracting agent for ultrasonic extraction to obtain a to-be-determined solution; and (2) injecting the to-be-tested solution into a high performance liquid chromatography-mass spectrometer, determining the (methyl) acrylic acid compound and the peak area thereof, and calculating according to the standard curve equation to obtain the content of the (methyl) acrylic acid compound in the to-be-tested textile sample. According to the method, the acrylic acid and the methacrylic acid in the textile can be accurately detected at the same time by adopting the ultrasonic extraction pretreatment-high performance liquid chromatography-mass spectrometry, the sensitivity is high, the operation is simple, the actual requirements can be met, in the concentration range of 0.5 mg / L to 100 mg / L, the linear correlation coefficient can reach 0.993 or above, the acrylic acid detection limit is 1.80 mg / kg, and the quantification limit is 5.30 mg / kg; the detection limit of methacrylic acid is 0.77 mg / kg, and the quantification limit is 2.40 mg / kg; the adding standard recovery rate is 81.74%-99.10%, and the relative standard deviation is 1.04%-2.89%.

Description

Technical Field

[0001] The invention belongs to the field of detection technology, and in particular relates to a method for determining (meth) acrylic acid compounds in textiles. Background Art

[0002] For a long time, textiles have been one of the essential items in daily life, and their safety and environmental protection issues have received widespread attention at home and abroad. Relevant laws and regulations stipulate that in addition to the quality of textiles themselves must meet production requirements, they must also meet safety regulations for human health and the environment during processing and use. In recent years, with the continuous improvement of my country's residents' consumption level, the functional demand for textiles has also been increasing. Among the ways to achieve functional finishing of textiles, coating finishing is the most common finishing method. Common coatings include polyacrylate coatings, polyurethane coatings, etc. The residual monomers in the polymer coatings will not only cause harm to the human body during use, but also greatly reduce the quality of the product.

[0003] International Textile Environmental Certification Standards The Blue Label Certification BSSL Consumer Safety Limit Substance List (v13.0) gives the restriction requirements and corresponding safety limits of (meth) acrylic acid in textiles, as shown in Table 1 below:

[0004] Table 1 BSSL Consumer Safety Limits List of Acrylic Acid Limits

[0005]

[0006] Note: A is textile products for infants and young children; B is textile products that come into direct contact with the skin; C is textile products that do not come into direct contact with the skin.

[0007] Although restrictions and regulations have been made on the residues of (meth)acrylic acid in textiles, there are relatively few studies on the detection technology of (meth)acrylic acid residues in textiles in the field of ecological textile testing technology. Establishing a detection method for (meth)acrylic acid on ecological textiles that meets international testing standards and conducting research on the detection technology of (meth)acrylic acid residues in ecological textiles are of great significance to the further expansion of my country's textile import and export trade. Summary of the invention

[0008] In order to solve the above problems in the prior art, the present invention proposes a method for determining (meth)acrylic acid compounds in textiles, adopts ultrasonic extraction pretreatment conditions and HPLC-MS analysis conditions, and establishes an HPLC-MS analysis method for simultaneously detecting (meth)acrylic acid in textiles, so as to achieve efficient detection of (meth)acrylic acid compounds.

[0009] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0010] A method for determining (meth) acrylic acid compounds in textiles comprises the following steps:

[0011] (1) Accurately weigh the textile sample to be tested, place it in a reactor, add an extractant for ultrasonic extraction, and obtain a test solution;

[0012] (2) injecting the test liquid into a high performance liquid chromatography-mass spectrometer, determining the (meth)acrylic acid compound and its peak area, and calculating the content of the (meth)acrylic acid compound in the test textile sample according to the standard curve equation.

[0013] The present invention is further configured such that the (meth) acrylic acid compound includes acrylic acid and methacrylic acid.

[0014] The present invention is further configured such that, in step (1), the mass volume ratio of the textile sample to be tested and the extractant is 1 g: (10-20) mL.

[0015] The present invention is further configured such that, in step (1), the extractant is methanol.

[0016] The present invention is further configured such that, in step (1), the ultrasonic extraction conditions are: extraction temperature is 40-60°C; extraction time is 40-45min; extraction power is 400-500W.

[0017] The present invention is further configured such that, in step (2), the test conditions of the high performance liquid chromatography-mass spectrometry instrument are:

[0018] A ZORBAX Eclipse Plus C18 column was selected, and the mobile phase was ultrapure water and methanol in a ratio of 95:5. 0.005-0.01 mol / L of ammonium acetate and 1-2 mL / L of ammonia water were added to adjust the response value and separation degree. The carrier gas flow rate was 0.1 mL / min.

[0019] The ion source was an ion source with Jet Stream electrospray (ESI) and the fragmentation voltage was 40-70V.

[0020] The present invention is further configured that the retention time and characteristic ions of the (meth) acrylic acid compound are shown in the following table:

[0021]

[0022] The present invention is further configured such that, in step (2), the process of making the standard curve equation is:

[0023] S1: Accurately weigh an appropriate amount of the (meth)acrylic acid compound standard to be tested, dissolve it in methanol and make up the volume, then dilute it into a series of gradient mixed standard working solutions;

[0024] S2: Inject the gradient mixed standard working solution into a high performance liquid chromatography-mass spectrometer to determine the (meth)acrylic acid compound to be measured and its peak area, draw a standard working curve with concentration as the horizontal coordinate and the peak area of ​​the (meth)acrylic acid compound as the vertical coordinate, and calculate the standard curve equation.

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

[0026] The present invention adopts ultrasonic extraction pretreatment-high performance liquid chromatography-mass spectrometry to achieve simultaneous and accurate detection of acrylic acid (AA) and methacrylic acid (MA) in textiles, and in the concentration range of 0.5 mg / L to 100 mg / L, the linear correlation coefficient can reach more than 0.993, the detection limit of acrylic acid is 1.80 mg / kg, and the detection limit of methacrylic acid is 0.77 mg / kg. The quantitative limit of acrylic acid is 5.30 mg / kg, the quantitative limit of methacrylic acid is 2.40 mg / kg, the spiked recovery rate is 81.74% to 99.10%, and the relative standard deviation (RSD) is 1.04% to 2.89%. The method can effectively separate and detect (meth) acrylic acid, has high sensitivity, is simple to operate, and can meet actual needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 a-1d is a graph showing the extraction effects of different extraction reagents on (meth)acrylic acid in spiked textiles of different materials and actual positive samples.

[0028] Figure 2 a-2c is a graph showing the extraction effect of different amounts of extractants on (meth)acrylic acid in spiked textiles of different materials.

[0029] Figure 3 a-3d is a graph showing the extraction effect of different extraction temperatures on (meth)acrylic acid in spiked textiles of different materials.

[0030] Figure 4 a-4d is a graph showing the extraction effect of (meth)acrylic acid in spiked textiles of different materials at different extraction times.

[0031] Figure 5 a-5d is a graph showing the extraction effect of different extraction powers on (meth)acrylic acid in spiked textiles of different materials.

[0032] Figure 6 These are the detection chromatograms of acrylic acid and methacrylic acid using different chromatographic columns.

[0033] Figure 7 The chromatograms of acrylic acid and methacrylic acid were detected using ammonium acetate and acetonitrile as mobile phases at different mobile phase ratios.

[0034] Figure 8 The chromatograms of acrylic acid and methacrylic acid were detected using pure water and acetonitrile as mobile phases at different mobile phase ratios.

[0035] Fig. 9 The chromatograms of acrylic acid and methacrylic acid were detected using ammonium acetate and methanol as mobile phases at different mobile phase ratios.

[0036] Fig.10 The chromatograms of acrylic acid and methacrylic acid were detected using pure water and methanol as mobile phases at different mobile phase ratios.

[0037] Fig.11 It is the detection chromatogram of acrylic acid and methacrylic acid with mobile phases of different ammonium acetate contents.

[0038] Fig.12 These are the detection chromatograms of acrylic acid and methacrylic acid with different ammonia concentrations as the mobile phase.

[0039] Fig.13 This is a graph showing the effect of different flow rates on the detection of acrylic acid and methacrylic acid.

[0040] Fig.14 This is a diagram showing the effect of different fragmentation voltages on the detection of acrylic acid and methacrylic acid.

[0041] Fig.15 It is the detection chromatogram of acrylic acid and methacrylic acid by HPLC-MS. DETAILED DESCRIPTION

[0042] The technical scheme of the present invention is clearly and thoroughly described below by specific embodiments in conjunction with the accompanying drawings. It should be understood that the following embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. Other embodiments obtained by ordinary technicians in this field without paying creative work should all be included in the protection scope of the present invention.

[0043] The materials used in the following examples are all conventional commercially available products. Experimental conditions not specified were performed according to the conditions recommended by the manufacturer or conventional experimental conditions in the art.

[0044] (1) Preparation of standard stock solution and mixed standard working solution:

[0045] Accurately weigh 0.2g of acrylic acid (AA) and methacrylic acid (MA) standards, dissolve them in methanol, and then transfer them to a 10mL volumetric flask to make up to volume, which is a standard stock solution with a concentration of 2000mg / L. Store it in a brown sample bottle to avoid light. According to the experimental design requirements, take the same volume of each (meth) acrylic acid standard stock solution and put it into the same brown volumetric flask to avoid light, and make up to volume with methanol to prepare the required concentration for the experiment, which is the mixed standard working solution. The mixed standard working solution must be prepared and used immediately.

[0046] (2) Preparation of spiked textiles:

[0047] Accurately weigh 1.00 g of blank adjacent fabrics of different materials, such as cotton, wool, polyester, and nylon, cut them into pieces smaller than 0.5 cm × 0.5 cm in size, and place them in a 50 mL sealable screw-mouth sample bottle. Measure different volumes of 100 mg / L mixed standard working solution and drop them onto the cut blank adjacent fabrics. Seal the bottle mouth and let it stand for 15 minutes.

[0048] Example 1. Optimization of experimental conditions

[0049] 1.1 Selection of extraction agent

[0050] Extraction experiments were conducted using extractants with different solubility. 1.0g of 6 spiked textiles of different materials (cotton, wool, polyester) were weighed, and the content of the mixed standard working solution on each spiked fabric was 10mg / kg. They were placed in a 50mL screw-mouth sample bottle, and 10mL of extractants methanol, acetonitrile, ethyl acetate, n-hexane, methyl tert-butyl ether and N,N-dimethylformamide were added for extraction. After ultrasonication at 50℃ for 40min, 1mL of the extract was measured and filtered through a filter white head and placed in a 2mL injection bottle. HPLC-MS was used for detection, and three groups of parallel experiments were performed, and the results were calculated as the average. At the same time, 100uL of 100mg / L mixed standard stock solution was added to another screw-mouth sample bottle, and the same volume of extractant was added without adding the lining fabric, and a control experiment was carried out to calculate the extraction rate.

[0051] At the same time, polyacrylic acid waterproof coating fabric was selected as the actual positive sample for synchronous extraction experiment: 1g of the actual positive sample was weighed, cut into small pieces of 0.5cm×0.5cm, placed in a 50mL sealable screw-mouth sample bottle, added with the above-mentioned extractant and extracted under the same extraction conditions. After the extraction, the peak area was detected by HPLC-MS, and 3 groups of parallel experiments were carried out, and the average value of the results was calculated.

[0052] The extraction effects of different extractants on (meth)acrylic acid in spiked textiles of different materials and actual positive samples, such as Figure 1 a-1d, where Figure 1a is cotton fabric, Figure 1 b is wool fabric, Figure 1 c is polyester fiber, Figure 1 d is the actual positive sample.

[0053] from Figure 1 It can be seen from a-1c that the extraction rate of n-hexane is the lowest, followed by methyl tert-butyl ether and ethyl acetate. The extraction efficiency of N,N-dimethylformamide is not much different from that of acetonitrile, but after extraction with N,N-dimethylformamide, the extractant extracts more other non-target components. When the extractant is filtered through the filter white head, the filter port is easily blocked, affecting the experimental results. When methanol is used as the extractant, the extraction effect is the best.

[0054] At the same time by Figure 1 It can be seen that in the detection of actual positive samples, the peak area value of methanol is relatively still the highest, and considering the low price of methanol and its polarity similar to acrylic acid, methanol is selected as the extraction reagent.

[0055] 1.2. Confirmation of the amount of extractant

[0056] Weigh 1.0g of 4 spiked textiles of different materials (cotton, wool, polyester), the content of the mixed standard working solution on each spiked fabric is 10mg / kg, put it in a 50mL screw-mouth sample bottle, add (5, 10, 15, 20)mL of chromatographic grade methanol, ultrasonicate at 50℃ for 40min, after the end of ultrasonication, measure 1mL of the extract, filter it through a filter, put it into a 2mL injection bottle, analyze and detect it by HPLC-MS, conduct 3 groups of parallel experiments, and calculate the average value of the results. Add 100uL of 100mg / L mixed standard stock solution to another screw-mouth sample bottle, add (5, 10, 15, 20)mL of extractant without adding adjacent fabric, and conduct a control experiment to calculate the extraction rate.

[0057] The extraction effect of different extractant dosages on (meth)acrylic acid in spiked textiles of different materials, such as Figure 2 a-2c, where Figure 2 a is cotton fabric, Figure 2 b is wool fabric, Figure 2 c is polyester fiber.

[0058] from Figure 2It can be seen from a-2c that with the increase in the amount of extractant, the extraction rate shows a trend of first rising and then stabilizing or slightly decreasing. The extraction rate is lowest when the amount of extractant is 5mL. The main reason is that the amount of extractant is too small to immerse 1.0g of the fabric to be tested, that is, the (meth)acrylic acid on the fabric cannot be completely extracted. When the amount of extractant is 10mL, 15mL, and 20mL, the extraction rate of (meth)acrylic acid is close. Therefore, the amount of extractant is selected to be 10-20mL.

[0059] 1.3 Confirmation of extraction temperature

[0060] The boiling point of the extraction reagent methanol used in this experiment is 64.7°C, and the indoor temperature of the detection room is 25°C. The extraction temperature during ultrasonic extraction should be lower than the boiling point of the selected extraction reagent. Therefore, the following temperature range of 20-60°C is used to explore the effect of extraction temperature on the extraction results.

[0061] Weigh 1.0g of 5 spiked textiles of different materials (cotton, wool, polyester), the content of the mixed standard working solution on each spiked fabric is 10mg / kg, put it in a 50mL screw-mouth sample bottle, add 10mL of chromatographic grade methanol, and ultrasonicate for 40min at different extraction temperatures (20℃, 30℃, 40℃, 50℃, 60℃). After the end of the ultrasound, take 1mL of the extract and filter it through a filter white head and put it into a 2mL injection bottle. HPLC-MS analysis and detection, perform 3 groups of parallel experiments, and calculate the average value of the results. Add 100uL of 100mg / L mixed standard stock solution to another screw-mouth sample bottle, add 10mL of extractant without adding lining fabric, and perform control experiments at different extraction temperatures (20℃, 30℃, 40℃, 50℃, 60℃) to calculate the extraction rate.

[0062] At the same time, polyacrylic acid waterproof coating fabric was selected as the actual positive sample for synchronous extraction experiment: 1g of the actual positive sample was weighed, cut into pieces of 0.5cm×0.5cm, placed in a 50mL sealable screw-mouth sample bottle, and 10mL of chromatographic grade methanol was added. The same extraction method as above was used, and extraction was performed at different extraction temperatures (20℃, 30℃, 40℃, 50℃, 60℃). After the extraction, the peak area was detected by HPLC-MS. Three groups of parallel experiments were performed, and the results were calculated as the average value.

[0063] The extraction effects of different extraction temperatures on (meth)acrylic acid in spiked textiles of different materials and actual positive samples, such as Figure 3 a-3d, where Figure 3 a is cotton fabric, Figure 3 b is wool fabric, Figure 3 c is polyester fiber, Figure 3d is the actual positive sample.

[0064] from Figure 3 It can be seen from a-3d that with the increase of extraction temperature, the thermal motion between molecules intensifies. Under the action of the extractant, the (meth) acrylic acid monomer is extracted from the fabric into the extract. The extraction temperature is between 20℃ and 50℃. The extraction temperature is positively correlated with the extraction rate and peak area. When the temperature rises to 50℃, the (meth) acrylic acid on the fabric is basically completely extracted and reaches equilibrium. Therefore, the extraction temperature is selected to be 40-60℃.

[0065] 1.4 Determination of extraction time

[0066] Weigh 1.0g of 5 spiked textiles of different materials (cotton, wool, polyester), the content of the mixed standard working solution on each spiked fabric is 10mg / kg, put it in a 50mL screw-mouth sample bottle, add 10mL of chromatographic grade methanol, and ultrasonically extract at 50℃ for 25min, 30min, 35min, 40min, and 45min respectively. After the end of the ultrasound, take 1mL of the extract and filter it through a filter white head and put it into a 2mL injection bottle. HPLC-MS analysis and detection, perform 3 groups of parallel experiments, and calculate the average value of the results. At the same time, add 100uL of 100mg / L mixed standard stock solution to another screw-mouth sample bottle, add 10mL of extractant without adding lining fabric, and perform control experiments at different ultrasonic times (25min, 30min, 35min, 40min, 45min) to calculate the extraction rate.

[0067] At the same time, polyacrylic acid waterproof coating fabric was selected as the actual positive sample for synchronous extraction experiment: 1g of the actual positive sample was weighed, cut into pieces of 0.5cm×0.5cm, placed in a 50mL sealable screw-mouth sample bottle, and 10mL of chromatographic grade methanol was added. The same extraction method as above was used, and ultrasonic extraction was performed at 50℃ for 25min, 30min, 35min, 40min, and 45min. After the extraction, the peak area was detected by HPLC-MS. Three groups of parallel experiments were performed, and the results were calculated as the average value.

[0068] The extraction effects of different extraction times on (meth)acrylic acid in spiked textiles of different materials and actual positive samples, such as Figure 4 a-4d, where Figure 4 a is cotton fabric, Figure 4 b is wool fabric, Figure 4 c is polyester fiber, Figure 4 d is the actual positive sample.

[0069] As can be seen from the figure, when the extraction time is between 25 and 40 minutes, the extraction time is positively correlated with the extraction rate and peak area. When the extraction time is between 40 and 45 minutes, as time goes by, the extraction rate and peak area no longer change much and tend to balance. Therefore, the extraction time is selected to be 40 to 45 minutes.

[0070] 1.5 Determination of extraction power

[0071] Weigh 1.0g of 5 spiked textiles of different materials (cotton, wool, polyester), the content of the mixed standard working solution on each spiked fabric is 10mg / kg, put it in a 50mL screw-mouth sample bottle, add 10mL of chromatographic grade methanol, ultrasonically extract at 50℃ for 40min, and the ultrasonic extraction power is 300W, 350W, 400W, 450W, 500W respectively. After the end of the ultrasound, take 1mL of the extract and filter it through a filter white head and put it into a 2mL injection bottle. HPLC-MS analysis and detection, three groups of parallel experiments are carried out, and the results are calculated as the average. At the same time, add 100uL of 100mg / L mixed standard stock solution to another screw-mouth sample bottle, add 10mL of extractant without adding lining fabric, and carry out control experiments at different ultrasonic powers (300W, 350W, 400W, 450W, 500W) to calculate the extraction rate.

[0072] At the same time, polyacrylic acid waterproof coating fabric was selected as the actual positive sample for synchronous extraction experiment: 1g of the actual positive sample was weighed, cut into pieces of 0.5cm×0.5cm, placed in a 50mL sealable screw-mouth sample bottle, and 10mL of chromatographic grade methanol was added. The same extraction method as above was used, and ultrasonic extraction was performed at 50°C for 40min. The ultrasonic extraction powers were 300W, 350W, 400W, 450W, and 500W, respectively. After the extraction, the peak area was detected by HPLC-MS. Three groups of parallel experiments were carried out, and the results were calculated as the average value.

[0073] The extraction effects of different extraction powers on (meth)acrylic acid in spiked textiles of different materials and actual positive samples, such as Figure 5 a~5d, where Figure 5 a is cotton fabric, Figure 5 b is wool fabric, Figure 5 c is polyester fiber, Figure 5 d is the actual positive sample.

[0074] As can be seen from the figure, when the extraction power is between 300W and 450W, the extraction power is positively correlated with the extraction rate and peak area. When the extraction power is between 450W and 500W, as the extraction power increases, the extraction rate and peak area no longer change much and tend to be balanced. Therefore, the ultrasonic power is selected to be 400-500W.

[0075] 1.6 Determination of chromatographic column

[0076] The structures and polarities of the two target components to be determined are too similar, so it is particularly important to select a suitable chromatographic column for the separation of the target components. In this experiment, two chromatographic columns with large differences in stationary phase, inner diameter, column length, and film thickness were selected to detect the 100 mg / L mixed standard working solution. The specific chromatographic columns are: Proshell 120Hilic chromatographic column (stationary phase is polysaccharide derivatives); ZORBAX Eclipse Plus C18 chromatographic column (stationary phase is dimethyl silica gel). The corresponding detection chromatographic Figure 6 shown.

[0077] from Figure 6 It can be seen that the Proshell 120Hilic column cannot separate the two substances, and the peak shape obtained by the Proshell 120Hilic column is wide and the peak area is low. The ZORBAX Eclipse Plus C18 column can better separate the two substances, with sharp and symmetrical peaks, good separation and high response value, which can fully meet the detection requirements. Therefore, the ZORBAX Eclipse Plus C18 column is used for detection.

[0078] 1.7 Determination of mobile phase and ratio

[0079] When the HPLC-MS instrument chromatographic column is determined, the detection separation and peak area under different types of mobile phases and different ratios are explored according to the polarity of (meth)acrylic acid. Because the two targets have similar chemical properties, strong polarity, early peak elution time, and similar peak elution ranges, this experiment mainly selects a high-ratio aqueous phase-low-ratio organic phase as the mobile phase ratio for optimization exploration. Specifically, ammonium acetate and acetonitrile, pure water and acetonitrile, ethanolammonium and methanol, and pure water and methanol were used as mobile phases, and detection was carried out under different mobile phase ratios (100:0, 95:5, 90:10, and 85:15). The detection separation and peak area are as follows: Figures 7-10 shown.

[0080] from Figure 7-8 It can be seen that when the mobile phase is ammonium acetate and acetonitrile, pure water and acetonitrile, the two substances cannot be separated, the peak shape is too broad, and the response value is too low; Fig. 9 As shown in the figure, when ammonium acetate and methanol are used as mobile phases, when the ratio is 100:0, it has good separation, but the peak area is too low, and when the mobile phase does not contain an organic phase, the aqueous phase is very likely to breed microorganisms, slowing down the filtration speed and causing clogging of the chromatographic column over time; Fig.10As shown, when pure water and methanol are used as the mobile phase, the peak area value is ideal, but the two targets cannot be separated and the chromatographic peaks show tailing; when the ratio is 90:10, compared with the ratios of 100:0 and 95:5, the peak area separation is reduced, and there are impurities at the tail of the peak.

[0081] After comprehensive consideration, methanol was selected as the organic phase, and the ratio of the aqueous phase to the organic phase was 95:5. The aqueous phase was compounded. Specifically, pure water and ammonium acetate were selected for compounding, and a small amount of ammonia was added to adjust the pH value, improve the response value and separation, and reduce peak tailing.

[0082] The effects of different ammonium acetate contents on the separation and peak area values ​​in liquid phase detection were further investigated. Specifically, when the ratio of aqueous phase to organic phase (methanol) was 95:5, the ammonia content was 0.5 mL / L, and the addition amounts of ammonium acetate were 0, 0.005 mol / L, 0.01 mol / L, and 0.02 mol / L, respectively, acrylic acid and methacrylic acid were detected by HPLC-MS. The test results are as follows: Fig.11 .

[0083] from Fig.11 It can be seen that when the ammonium acetate content is 0.005 mol / L, the separation of the chromatographic peaks is good, the two target substances can be completely separated, and have a good peak area value.

[0084] Further study the effect of different ammonia contents on the separation and peak area in liquid phase detection. Specifically, when the ratio of aqueous phase to organic phase (methanol) was 95:5, ammonium acetate was 0.005 mol / L, and the amount of ammonia added was 0, 1 mL / L, and 2 mL / L, the HPLC-MS detection chromatograms of acrylic acid and methacrylic acid were as follows: Fig.12 shown.

[0085] The addition of ammonia can reduce the contact between sample molecules and silanol groups in the stationary phase, reduce the interaction between polar groups and silanol groups, thereby improving peak shape and reducing tailing. Fig.12 It can be seen that when no ammonia water is added, the two substances are slightly separated, but the separation degree between acrylic acid and methacrylic acid is very low, the response value is not high, and the peak of methacrylic acid has obvious tailing; when 2mL / L ammonia water is added, the pH is 10.12, and when 1mL / L ammonia water is added, the pH is 9.8. Compared with adding 2mL / L ammonia water, the peak shape of adding 1mL / L ammonia water is symmetrical and sharp, and has a better response value. Therefore, adding 1mL / L ammonia water is selected.

[0086] 1.8 Determination of flow rate

[0087] In liquid chromatography detection, flow rate is one of the most important parameters. If the flow rate is too fast, the sample will stay in the chromatographic column for too short a time, resulting in the inability to separate certain target components. If the flow rate is too slow, the separation time will be prolonged, affecting the test efficiency.

[0088] In order to select the most suitable flow rate for HPLC-MS chromatography analysis, this experiment explored the effect of flow rate in the range of 0.1-0.5 mL / min on the HPLC chromatography separation of acrylic acid and methacrylic acid. The test results are as follows: Fig.13 shown.

[0089] from Fig.13 It can be seen that when the flow rate is 0.1 mL / min, the sample stays in the chromatographic column for a longer time, which makes the ionization efficiency higher and the response value better.

[0090] 1.9 Determination of fragmentation voltage

[0091] In order to obtain the best experimental results, this experiment explored the influence of several different fragmentation voltages between 40V and 110V on the determination of 20mg / L (meth) acrylic acid mixed standard working solution. The test results are as follows: Fig.14 shown.

[0092] As can be seen from the figure, the change trends of acrylic acid and methacrylic acid are similar. As the fragmentation voltage increases, the peak area of ​​the chromatographic peak gradually increases. After reaching a peak, the peak area gradually decreases as the fragmentation voltage increases. The main reason is that increasing the voltage will increase the transmission efficiency of the parent ion, causing more parent ions to enter the collision cell, but when the voltage exceeds a certain value, the high voltage will cause the parent ion to ionize, thereby reducing the response value. Therefore, the optimal fragmentation voltage is 40V to 70V.

[0093] 1.10. Retention time and characteristic ions

[0094] The optimal instrument conditions optimized in the above Examples 1.6-1.9 were used to detect the 20 mg / L (meth)acrylic acid mixed standard working solution, and the retention times and characteristic ions of the two (meth)acrylic acid target substances, as well as the corresponding chromatograms, are shown in Tables 2 and 3, respectively. Fig.15 As shown, the optimal instrument conditions are as follows:

[0095] A ZORBAX Eclipse Plus C18 column was selected, and the mobile phase was ultrapure water and methanol in a ratio of 95:5. 0.005 mol / L of ammonium acetate and 1 mL / L of ammonia water were added. The response value and separation degree were adjusted. The carrier gas flow rate was 0.1 mL / min, the ion source was an ion source with Jet Stream electrospray (ESI), and the fragmentation voltage was set to 50 V.

[0096] Table 2 Retention times and characteristic ions of two (meth) acrylic acid compounds

[0097]

[0098] Example 2: Methodological Verification

[0099] 2.1 Linear relationship and detection limit

[0100] 1mL of the (meth) acrylic acid mixed standard working solution with a concentration gradient of 0.5mg / L, 1mg / L, 2mg / L, 5mg / L, and 10mg / L was drawn into a 2mL injection bottle, and then injected into a high performance liquid chromatography-mass spectrometer for detection to obtain a liquid chromatography-mass spectrometer, with the sample concentration as the horizontal axis and the peak area as the vertical axis to draw a standard curve. The test conditions of the liquid chromatography-mass spectrometer are: select a ZORBAX Eclipse Plus C18 chromatographic column, the mobile phase is ultrapure water and methanol, the ratio is 95:5, and add 0.005mol / L of ammonium acetate, 1mL / L of ammonia water, adjust the response value and separation, the carrier gas flow rate is 0.1mL / min, the ion source is an ion source (ESI) with Jet Stream electrospray, and the fragmentation voltage is set to 50V. The linear range, linear equation and correlation coefficient of acrylic acid and methacrylic acid obtained are shown in Table 3 below.

[0101] Table 3 Linear range, linear equation and correlation coefficient of acrylic acid and methacrylic acid

[0102]

[0103] It can be seen from Table 3 that in the concentration range of 0.005 mg / L to 0.01 mg / L, the method has a good linear relationship, and the linear correlation coefficients of acrylic acid and methacrylic acid are both above 0.9993, which can meet the actual test needs.

[0104] According to the above method, the detection limit and quantification limit of acrylic acid and methacrylic acid were measured through low concentration spike test, as shown in Table 4 below:

[0105] Table 4 Detection limit and quantification limit test results of acrylic acid and methacrylic acid

[0106]

[0107] As shown in Table 4, the detection limit of acrylic acid and methacrylic acid detected by HPLC-MS is 1.80 mg / kg and 0.77 mg / kg, respectively. The quantification limit of acrylic acid and methacrylic acid is 5.30 mg / kg and 2.40 mg / kg, respectively, which can meet the daily detection requirements.

[0108] 2.2 Recovery and precision

[0109] In order to reflect the universality of the determination method of the present invention, based on four textiles of different materials (cotton fabric, wool fabric, polyester fiber, polyamide fiber), three different spiked amounts (5 mg / kg, 500 mg / kg, 1000 mg / kg) in the range of 5 to 1000 mg / kg were selected to calculate the spiked recovery rate and relative standard deviation, and the results shown in the following Table 5 were obtained.

[0110] Table 5 Recovery and relative standard deviation of (meth)acrylic acid detected by HPLC-MS (n=6)

[0111]

[0112] From the results in Table 5, it can be seen that at the three spiking levels, the spiked recovery rates of (meth)acrylic acid in cotton fabrics are between 81.74% and 96.43%, the spiked recovery rates of (meth)acrylic acid in wool fabrics are between 82.15% and 96.35%, the spiked recovery rates of (meth)acrylic acid in polyester fibers are between 93.26% and 98.65%, and the spiked recovery rates of (meth)acrylic acid in polyamide fibers are between 93.58% and 99.10%.

[0113] The relative standard deviation of (meth)acrylic acid in different textiles detected by this method is less than 2.89%, indicating that the ultrasonic extraction-high performance liquid chromatography-mass spectrometry detection method has good reproducibility and accuracy in the detection of (meth)acrylic acid in textiles.

[0114] Application Example 1

[0115] The method for determining (meth) acrylic acid compounds in a positive sample comprises the following steps:

[0116] (1) Accurately weigh the positive sample and place it in a reactor, add the extraction solvent methanol, the mass volume ratio of the positive sample to the extraction solvent is 1g:10mL, place it in an ultrasonic generator at 40°C, the working frequency is 400W, and extract for 30 minutes to obtain a test solution;

[0117] (2) The standard curve equation and HPLC-MS test conditions were the same as those in Example “2.1. Linear relationship and detection limit”;

[0118] (3) Injecting the test solution obtained in step (1) into HPLC-MS, measuring the two (meth)acrylic acids and their peak areas, and calculating the contents of the two (meth)acrylic acids in the positive sample according to the standard curve equation.

[0119] Finally, it was determined that the positive sample contained 1.2 mg / kg of methacrylic acid and 46 mg / kg of acrylic acid.

[0120] The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any equivalent substitutions or modifications based on the inventive concept of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for determining (meth) acrylic acid compounds in textiles, characterized in that: The steps include: (1) Accurately weigh the textile sample to be tested, place it in a reactor, add an extractant for ultrasonic extraction, and obtain a test solution; (2) injecting the test liquid into a high performance liquid chromatography-mass spectrometer, determining the (meth)acrylic acid compound and its peak area, and calculating the content of the (meth)acrylic acid compound in the test textile sample according to the standard curve equation.

2. The method for determining (meth) acrylic compounds in textiles according to claim 1, characterized in that: The (meth)acrylic compound includes acrylic acid and methacrylic acid.

3. The method for determining (meth) acrylic compounds in textiles according to claim 1, characterized in that: In step (1), the mass volume ratio of the textile sample to be tested and the extractant is 1 g: (10-20) mL.

4. The method for determining (meth) acrylic acid compounds in textiles according to claim 1, characterized in that: In step (1), the extractant is methanol.

5. The method for determining (meth) acrylic acid compounds in textiles according to claim 1, characterized in that: In step (1), the ultrasonic extraction conditions are: extraction temperature is 40-60°C; extraction time is 40-45min; extraction power is 400-500W.

6. The method for determining (meth) acrylic acid compounds in textiles according to claim 1, characterized in that: In step (2), the test conditions of the high performance liquid chromatography-mass spectrometry are: A ZORBAX Eclipse Plus C18 column was selected, and the mobile phase was ultrapure water and methanol in a ratio of 95:

5. 0.005-0.01 mol / L of ammonium acetate and 1-2 mL / L of ammonia water were added to adjust the response value and separation degree. The carrier gas flow rate was 0.1 mL / min. The ion source was an ion source with Jet Stream electrospray (ESI) and the fragmentation voltage was 40-70V.

7. The method for determining (meth) acrylic acid compounds in textiles according to claim 1, characterized in that: The retention time and characteristic ions of the (meth) acrylic acid compounds are shown in the following table:

8. The method for determining (meth) acrylic acid compounds in textiles according to claim 1, characterized in that: In step (2), the process of making the standard curve equation is as follows: S1: Accurately weigh an appropriate amount of the (meth)acrylic acid compound standard to be tested, dissolve it in methanol and make up to volume, then dilute it into a series of gradient mixed standard working solutions; S2: Inject the gradient mixed standard working solution into a high performance liquid chromatography-mass spectrometer to determine the (meth)acrylic acid compound to be measured and its peak area, draw a standard working curve with concentration as the horizontal axis and the peak area of ​​the (meth)acrylic acid compound as the vertical axis, and calculate the standard curve equation.

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