A method for determining herbicide ether and fluazifop-butyl in cosmetics based on GC-MS

Abstract

The present invention discloses a method for determining herbicide ether and fluazifop-butyl in cosmetics based on GC-MS, which belongs to the field of cosmetics detection technology. The method comprises the following steps: S1, extraction: mixing the sample with an extraction solvent and performing ultrasonic extraction, centrifugation, taking the supernatant and blowing nitrogen to obtain a liquid to be purified containing the extract; S2, purification: taking the liquid to be purified in step S1 and passing it through a solid phase extraction column, collecting the filtrate, blowing it dry with nitrogen under a 45 ° C water bath, then dissolving it with an organic solvent and constant volume, mixing it evenly, filtering to obtain a purified liquid; S3, detection: using a gas chromatography-mass spectrometer to detect and analyze the purified liquid obtained in step S2. This method realizes the detection of herbicide ether and fluazifop-butyl in different matrix cosmetics for the first time, and has the advantages of good separation, sensitivity, accuracy and high precision.

Description

Technical Field

[0001] The present invention belongs to the technical field of cosmetics detection, and in particular relates to a method for determining herbicide ether and fluazifop-butyl in cosmetics based on GC-MS. Background Art

[0002] Nitrofen is an ether-based selective contact herbicide. Due to its low toxicity to aquatic animals, it quickly replaced sodium pentachlorophenol for rice paddy weed control in the 1960s and played a significant role in chemical weed control in rice paddies in my country. However, with the advancement of animal testing, it has been confirmed that nitrofen is carcinogenic, teratogenic, and mutagenic to mammals. The teratogenic and carcinogenic effects after skin absorption are far more pronounced than after oral administration. Consequently, the Ministry of Agriculture and Rural Affairs has issued a ban on the further use of nitrofen. Fluazifop-butyl, also known as vinazene, is a systemic foliar herbicide with an acute oral LD50 of 3328 mg / kg in rats and 1490 mg / kg in male and 1770 mg / kg in female mice. It is mildly irritating to the eyes and non-irritating to the skin. my country's "Technical Specifications for Safety of Cosmetics" (2015 edition) clearly stipulates that nitrofen and fluazifop-butyl must not be detected in cosmetics. In recent years, consumers have increasingly sought natural cosmetics, with functional cosmetics such as plant extracts gaining popularity. However, the use of pesticides such as herbicides during plant cultivation is unavoidable, and these pesticides can be introduced into plant extracts during the production process. Long-term use of these cosmetics can potentially lead to allergic dermatitis, carcinogenesis, and teratogenicity.

[0003] At present, there are no reports on the detection methods of herbicides and fluazifop-butyl in cosmetics, and most of them are concentrated in the field of food testing. Therefore, obtaining a method that can quickly detect herbicides and fluazifop-butyl in cosmetics is one of the research directions in the field of cosmetics testing. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a method for determining herbicide ether and fluazifop-butyl in cosmetics using a gas chromatography-mass spectrometer (GC-MS). The method realizes the detection of herbicide ether and fluazifop-butyl in cosmetics with different matrices. The method is simple and easy to operate, reduces the amount of organic solvent used, and meets the detection requirements of high recovery and high sensitivity.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] A method for determining herbicide ether and fluazifop-butyl in cosmetics by GC-MS comprises the following steps:

[0007] S1. Extraction: Mix the sample with the extraction solvent and perform ultrasonic extraction, centrifuge, and take the supernatant and blow nitrogen to obtain a solution to be purified containing the extract;

[0008] S2, purification: the liquid to be purified in step S1 is passed through a solid phase extraction column, the filtrate is collected, and dried with nitrogen in a water bath at 45°C, then dissolved in an organic solvent and fixed to volume, mixed evenly, and filtered through an organic membrane to obtain a purified liquid;

[0009] S3. Detection: The purified liquid obtained in step S2 is detected and analyzed using a gas chromatography-mass spectrometer.

[0010] Furthermore, the extraction solvent is any one of acetonitrile, acetonitrile-water solution (V / V=9:1), and acetonitrile-water solution (V / V=8:2).

[0011] Preferably, the extraction solvent is acetonitrile-water solution (V / V=9:1).

[0012] In the present invention, acetonitrile-water solution (V:V=9:1) is preferably used for extraction, and the recovery rates of herbicide ether and fluazifop-butyl in cosmetics with different matrices are 82.97-102.18% and 86.33-113.47%, respectively, with good recovery effect.

[0013] Furthermore, the solid phase extraction column is a neutral alumina solid phase extraction column (AL-N, 500 mg / 6 mL), an octadecyl silica gel solid phase extraction column (C 18 , 200 mg / 3 mL), Florisil + neutral alumina composite column (Florisil+AL-N, 1 g / 6 mL+1 g), N-propylethylenediamine solid phase extraction column (PSA, 200 mg / 3 mL), polystyrene / divinylbenzene copolymer solid phase extraction column (HLB, 500 mg / 6 mL), enhanced lipid removal solid phase extraction column (EMR-Lipid, 600 mg / 6 mL).

[0014] Preferably, the solid phase extraction column is an enhanced lipid removal solid phase extraction column (EMR-Lipid, 600 mg / 6 mL).

[0015] In the present invention, when an enhanced lipid removal solid phase extraction column (EMR-Lipid, 600 mg / 6 mL) is preferably used for purification, the recovery rates of herbicide ether and fluazifop-butyl in cosmetics with different matrices are 85.74% and 82.39%, respectively, and the recovery effect is good.

[0016] Furthermore, the specific extraction steps of step S1 are: adding an extraction solvent to the sample, oscillating for 2-2.5 minutes to fully mix the sample and the extraction solvent, extracting under ultrasound for 10-20 minutes, centrifuging at 9000-11000 r / min for 5-10 minutes, taking all the supernatant and blowing it with nitrogen to 5 mL to obtain the liquid to be purified.

[0017] Furthermore, the sample in step S1 is specifically an essential oil or cream cosmetic, and the specific extraction steps of step S1 are: weighing 0.50 g (accurate to 0.001 g) of the cosmetic sample into a 50 mL centrifuge tube, adding 10 mL of acetonitrile-water solution (V:V=9:1), vortexing for 2 minutes to fully mix the sample and the extraction solvent, ultrasonic extraction for 15 minutes, centrifuging at 10000 r / min for 5 minutes, transferring all the supernatant to a 15 mL test tube, blowing nitrogen to 5 mL in a 45°C water bath, and waiting for purification.

[0018] Furthermore, the specific purification steps in step S2 are as follows: the entire liquid to be purified is loaded onto an EMR-Lipid solid-phase extraction column, the filtrate is collected, and the filtrate is blown to near dryness in a 45°C water bath with nitrogen. Then, 2 mL of ethyl acetate is added to redissolve the residue, and the filtrate is blown to near dryness in a 45°C water bath with nitrogen, and this process is repeated once. Finally, the volume is adjusted to 1 mL with ethyl acetate, filtered through a 0.22 μm microporous membrane, and loaded onto the instrument for testing.

[0019] Furthermore, the detection conditions of the gas chromatography-mass spectrometry are as follows: chromatographic column: HP-5MS capillary column, column length 30.0m, inner diameter 0.25mm, film thickness 0.25μm; programmed temperature: initial temperature 100°C, hold for 2min, heat to 230°C at a rate of 50°C / min, continue to heat to 250°C at a rate of 2°C / min, and then heat to 310°C at a rate of 30°C / min, and hold for 5min; inlet temperature: 270°C; mass spectrometry interface temperature: 280°C; ion source temperature: 230°C; carrier gas: He, purity ≥99.999%, constant flow 1.0mL / min; injection volume: 1μL; injection mode: pulsed non-divided flow; ionization mode: EI; solvent delay: 5min; mass spectrometry scanning mode: selected ion mode.

[0020] Compared with the prior art, the present invention has achieved beneficial technical effects:

[0021] The present invention establishes for the first time a GC-MS method for determining herbicide ether and fluazifop-butyl in cosmetics with different matrices. The samples are extracted with an extraction solvent, purified by a solid phase extraction column, and then tested on a machine. Statistical results show that the average recovery rate of this method is between 81.47% and 109.87%, and the relative standard deviation (RSD) is between 0.50% and 10.97%, both of which meet the requirements of SN / T0001-2016. The detection limit of herbicide ether is 0.020 mg / kg, and the limit of quantification is 0.050 mg / kg; the detection limit of fluazifop-butyl is 0.004 mg / kg, and the limit of quantification is 0.010 mg / kg.

[0022] The method provided by the present invention has good separation of herbicide ether and fluazifop-butyl, high sensitivity, accuracy and precision, and the pretreatment method is simple and rapid. The method can be used for risk assessment and screening monitoring of herbicide ether and fluazifop-butyl in cosmetics, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1-Figure 2 The effect of the chromatographic column on the separation and response of compounds ( Figure 1 It is DB-1701; Figure 2 for HP-5MS);

[0024] Figure 3-Figure 4 The influence of programmed temperature conditions ( Figure 3 For method 1; Figure 4 for method 2);

[0025] Figure 5-Figure 6 The effect of extraction solvent on compound recovery ( Figure 5 For face cream; Figure 6 for essential oils);

[0026] Figure 7 is the effect of solid phase extraction column on compound recovery;

[0027] Figure 8-Figure 9 The effect of matrix on the purification effect of solid phase extraction column ( Figure 8 For face cream; Figure 9 for essential oils). DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the examples. However, the scope of protection claimed in the present invention is not limited to the following specific examples, and the reagents or instruments used in the detection method of the present invention can be purchased from the market.

[0029] Example 1

[0030] This embodiment provides a method for determining herbicide ether and fluazifop-butyl in cosmetics (the cosmetics in this embodiment are essential oils) by GC-MS, the method comprising the following steps:

[0031] S1. Extraction: Weigh 0.50 g (accurate to 0.001 g) of the cosmetic sample into a 50 mL centrifuge tube, add 10 mL of acetonitrile-water solution (V / V = 9:1), vortex for 2 min to fully mix the sample and the extraction solvent, perform ultrasonic extraction for 15 min, centrifuge at 10,000 rpm for 5 min, transfer all the supernatant to a 15 mL test tube, blow nitrogen to 5 mL in a 45 °C water bath, and wait for purification.

[0032] S2. Cleanup: Load the entire volume of the solution to be purified onto an EMR-Lipid solid-phase extraction column, collect the filtrate, and purge it with nitrogen in a 45°C water bath until nearly dry. Then, add 2 mL of ethyl acetate to redissolve the residue, and repeat the process once more by purging it with nitrogen in a 45°C water bath until nearly dry. Finally, dilute the volume to 1 mL with ethyl acetate, filter through a 0.22 μm microporous membrane, and load the column for analysis.

[0033] S3. Detection: The purified liquid obtained in step S2 is detected and analyzed using a gas chromatography-mass spectrometer.

[0034] The gas chromatography-mass spectrometry conditions of this example are as follows: chromatographic column: HP-5MS capillary column, column length: 30.0 m, inner diameter: 0.25 mm, film thickness: 0.25 μm; programmed temperature: initial temperature: 100° C., hold for 2 min, then heat to 230° C. at a rate of 50° C. / min, continue to heat to 250° C. at a rate of 2° C. / min, then heat to 310° C. at a rate of 30° C. / min, and hold for 5 min; inlet temperature: 270° C.; mass spectrometry interface temperature: 280° C.; ion source temperature: 230° C.; carrier gas: He, purity >99.999%, constant flow: 1.0 mL / min; injection volume: 1 μL; injection mode: pulsed splitless; ionization mode: EI; solvent delay: 5 min; mass spectrometry scanning mode: selected ion mode.

[0035] Examples 2-5

[0036] With reference to Example 1, the difference from Example 1 is that the cosmetics in Examples 2-5 are toner, cream, gel, lipstick, and loose powder, in that order.

[0037] The gas chromatography-mass spectrometry conditions in this example are the same as those in Example 1.

[0038] The following examples investigate the effects of various factors on the detection of herbicide ether and fluazifop-butyl in cosmetics with different bases.

[0039] The preparation of the standard working solutions of herbicide ether and fluazifop-butyl is as follows:

[0040] (1) Preparation of standard stock solution of herbicide ether: Accurately weigh 10 mg (accurate to 0.01 mg) of herbicide ether standard and place it in a 10 mL volumetric flask. Dissolve it with n-hexane and dilute to the mark. Shake well to a concentration equivalent to 1000 mg / L. Store at -18°C in the dark. The shelf life is 12 months.

[0041] (2) Preparation of fluazifop-butyl standard stock solution: Accurately weigh 10 mg (accurate to 0.01 mg) of fluazifop-butyl standard solution and place it in a 10 mL volumetric flask. Dissolve it in methanol and dilute to the mark. Shake well. The concentration is equivalent to 1000 mg / L. Store at -18°C away from light. The shelf life is 12 months.

[0042] (3) Preparation of mixed standard intermediate solution: Accurately measure 0.25 mL and 0.05 mL of herbicide ether and fluazifop-butyl standard stock solutions respectively and place them in a 25 mL volumetric flask. Dilute with ethyl acetate and make up to the mark. Shake well. The herbicide ether concentration is equivalent to 10 mg / L and the fluazifop-butyl concentration is equivalent to 2 mg / L. Store at -18°C away from light. The shelf life is 1 month.

[0043] (4) Mixed Standard Working Solution: Accurately measure the mixed standard intermediate solution and dilute it with a blank matrix solution (the liquid obtained by treating the cosmetic sample without herbicide ether and fluazifop-butyl with S1 and S2 as described in Example 1) to form a series of standard working solutions. The herbicide concentrations are 0.02, 0.05, 0.1, 0.2, and 0.5 mg / L, and the fluazifop-butyl concentrations are 0.004, 0.01, 0.02, 0.04, and 0.1 mg / L, respectively. Prepare and use immediately.

[0044] Example 6 Optimization of gas chromatography and mass spectrometry conditions

[0045] (1) Optimization of mass spectrometry conditions

[0046] Full scan analysis of herbicide ether and fluazifop-butyl was performed in EI ionization mode. The ion with the largest intensity was selected as the quantitative ion, and 2 to 3 ions with the second largest intensity were selected as the qualitative ions, as shown in Table 1.

[0047] Table 1 Quantitative and qualitative ions of compounds

[0048] Compound Quantitative ion (m / z) Qualifier ion (m / z) Herbicide 202 283,285 fluazifop-butyl 282 383,254

[0049] (2) Optimization of gas chromatography conditions

[0050] a. Selection of chromatographic columns

[0051] This example compares the responses of two chromatographic columns, DB-1701 (column length 30.0m, inner diameter 0.32mm, film thickness 0.25μm) and HP-5MS capillary column (column length 30.0m, inner diameter 0.25mm, film thickness 0.25μm), to herbicide ether and fluazifop-butyl. Figure 1-Figure 2 .

[0052] DB-1701 contains 50% benzene rings and 50% oxide rings. This type of column is often used in the analysis of pesticides. HP-5MS is a 5% phenyl-methyl polysiloxane non-polar column and is also a column with a wide range of applications. Figure 1-Figure 2It can be seen that when the two capillary columns are used to analyze herbicide ether and fluazifop-butyl, DB-1701 has better separation, but the peak shape of the collected compounds is slightly tailing, and when the standard solution of the same concentration is loaded on the machine, the response is not as good as HP-5MS. In addition, considering that HP-5MS is more applicable and more universal in the laboratory, the HP-5MS capillary column (column length 30.0m, inner diameter 0.25mm, film thickness 0.25μm) is selected as the chromatographic column of the present invention.

[0053] b. Optimization of programmed temperature conditions

[0054] This example refers to the literature and standards of relevant herbicides and fluazifop-butyl, and the programmed temperature method compares method 1 (initial temperature 100°C, hold for 2 min, heat to 230°C at a rate of 50°C / min, continue to heat to 250°C at a rate of 2°C / min, then heat to 280°C at a rate of 30°C / min, hold for 5 min) and method 2: (initial temperature 100°C, hold for 2 min, heat to 230°C at a rate of 50°C / min, continue to heat to 250°C at a rate of 2°C / min, then heat to 310°C at a rate of 30°C / min, hold for 5 min). The results are shown in Table 1. Figure 3-Figure 4 .

[0055] Depend on Figure 3-4 It can be seen that when the matrix was added to collect the spectrum, a bulge was found at 7-10 minutes. Because the peaks of herbicide ether and fluazifop-butyl are between 9 and 9.5 minutes, this bulge seriously affects the baseline and the response of herbicide ether and fluazifop-butyl. The reason for this analysis may be that the cosmetic matrix is ​​complex, and 280°C cannot make the impurities flow out, but are retained on the capillary column. Therefore, the temperature program was adjusted to 310°C and maintained for 5 minutes. The bulge phenomenon disappeared when the machine was tested. Therefore, method 2 was selected as the temperature program condition of the present invention.

[0056] Example 7 Effect of Different Extraction Solvents on the Recovery of Herbicides and Fluazifop-P-ethyl in Cosmetics

[0057] 0.1 mL of a 1000 ng / mL mixed standard solution of herbicide ether and fluazifop-butyl was added to a blank cosmetic sample (cream, essential oil cosmetics), and three extraction solvents were selected: acetonitrile, acetonitrile-water solution (V / V=9:1), and acetonitrile-water solution (V / V=8:2). The acetonitrile extraction method was to blow nitrogen to 4.8 mL after extraction, and then add 1.2 mL of water to make the liquid to be purified contain 20% water. The extraction methods of acetonitrile-water solution (V / V=9:1) and acetonitrile-water solution (V / V=8:2) were treated with reference to steps S1 and S2 in Example 1 to obtain a purified solution, which was then detected and analyzed by GC-MS, and the recoveries of herbicide ether and fluazifop-butyl were calculated, respectively. The results are shown in FIG. Figure 5、 Figure 6 shown.

[0058] Figure 5 The results showed that when the cream was extracted with acetonitrile, the recoveries of herbicide ether and fluazifop-butyl were 77.52% and 73.37%, respectively; when extracted with acetonitrile-water solution (V / V=9:1), the recoveries of the two were 102.18% and 113.47%, respectively; when extracted with acetonitrile-water solution (V / V=8:2), the recoveries of the two were 131.11% and 75.29%, respectively. Both acetonitrile and acetonitrile-water solution (V / V=9:1) were acceptable for extraction. Figure 6 The results showed that the essential oil was extracted with acetonitrile or an acetonitrile-water solution (V / V = 9:1), with recoveries ranging from 80.75% to 87.85%. The recovery of fluazifop-butyl was lower, at 63.94%, when extracted with an acetonitrile-water solution (V / V = 8:2). However, during the acetonitrile extraction experiment, the clear liquid became turbid and flocculent matter was observed to precipitate. The acetonitrile-water solution (V / V = 8:2) also had a high water content and prolonged nitrogen purge time. Therefore, the acetonitrile-water solution (V / V = 9:1) was used for extraction.

[0059] Example 8 Investigating the Effects of Different Solid Phase Extraction Columns on the Recovery of Herbicide-Ether and Fluazifop-Phthiophene

[0060] 0.1 mL of a 1000 ng / mL mixed standard solution of herbicide ether and fluazifop-butyl was prepared by mixing with different AL-N, C 18 , Florisil + AL-N composite column, PSA, HLB and EMR-Lipid six solid phase extraction columns (due to the different performances of the six solid phase extraction columns, different purification methods are required. The five solid phase extraction columns of AL-N, C18, Florisil + AL-N composite column, PSA, and HLB are activated with 5 mL of n-hexane, 1 mL of a mixed standard solution of 100 μg / L is loaded, eluted with 8 mL of acetone + n-hexane (V:V, 4:6), and the eluate is collected. It is blown to near dryness with nitrogen in a 45°C water bath, and the volume is made up to 1 mL with ethyl acetate, and analyzed by GC-MS. EMR-Lipid is purified by referring to step S2 in Example), and then detected and analyzed by GC-MS, and the recoveries of herbicide ether and fluazifop-butyl are calculated respectively, as shown in FIG. Figure 7 As shown in the results, AL-N, HLB and EMR-Lipid had no obvious adsorption on herbicide ether and fluazifop-butyl, and the recovery rates were between 84.54% and 103.21%. 18 The recovery of Florisil+AL-N composite column was relatively low, ranging from 13.94% to 51.41%. Therefore, the next step was to investigate the purification effect of AL-N, HLB and EMR after adding matrix.

[0061] Example 9 Investigating the Effect of Screened Solid Phase Extraction Columns on the Recovery of Herbicide-Ether and Fluazifop-Phthiophene

[0062] 0.1 mL of a 1000 ng / mL mixed standard solution of herbicide ether and fluazifop-butyl was added to a blank cosmetic sample (cream, essential oil cosmetics), and the purified solution was obtained by processing in step S2 of reference example 1. The purified solution was processed using the screened AL-N, HLB and EMR-Lipid solid phase extraction columns, and the purification method was carried out according to reference example 8. The sample was then detected and analyzed by GC-MS, and the recoveries of herbicide ether and fluazifop-butyl were calculated, as shown in FIG. Figure 8 、 9 The results showed that for cream samples, the recovery rates of herbicide ether and fluazifop-butyl were 0% and 91.81% respectively when cleaned up using an AL-N solid-phase extraction cartridge. When cleaned up using an HLB solid-phase extraction cartridge, the recoveries of both herbicide ether and fluazifop-butyl were 0% and 105.03% and 82.39% respectively when cleaned up using EMR-Lipid. Therefore, EMR-Lipid can be selected as the cleanup column for cream samples. For essential oil samples, the recovery rates of herbicide ether and fluazifop-butyl were 0% and 71.46% when cleaned up using an AL-N cartridge. When cleaned up using an HLB cartridge, the recoveries of herbicide ether and fluazifop-butyl were 118.36% and 119.73% respectively. When cleaned up using EMR-Lipid, the recoveries of herbicide ether and fluazifop-butyl were 85.74% and 82.39% respectively. Therefore, EMR-Lipid can also be selected as the cleanup column for essential oil samples. Therefore, the EMR-Lipid solid phase extraction column is selected as the solid phase extraction column of the present invention.

[0063] Example 10 Influence of Matrix Effect on the Recovery of Herbicides and Fluazifop-P-ethyl in Cosmetics

[0064] The matrix effect (ME) refers to the interference of the matrix in the analytical process and its influence on the analytical results. It is calculated as ME (%) = (slope of the linear equation of the matrix standard curve / slope of the linear equation of the solvent standard curve - 1) × 100%. When the ME value is between ±5%, the matrix effect is generally considered to be absent; when the ME value is between ±20%, the matrix effect is considered to be minimal, and the pure solvent curve can be used for quantitative analysis of the target compound; when the ME value is outside ±20%, the blank matrix curve should be used for quantitative analysis. In this study, standard curves were prepared using blank matrix solution and ethyl acetate as solvents for comparison. The results are shown in Table 2. The matrix effect of all six blank matrices was inhibitory, with the inhibitory effect ranging from 19.21% to 74.23%. Therefore, to reduce the influence of matrix effects, the standard curves established in this standard are prepared using blank matrix.

[0065] Table 2 Matrix effects of six matrices

[0066]

[0067] Examples 11 and 12 are used to verify the accuracy, sensitivity and repeatability of the detection method of the present invention.

[0068] Example 11

[0069] The mixed standard solution was diluted into different gradient concentrations using blank matrix extraction solvent, and the sample was analyzed according to the optimized instrument method. The standard curve was drawn with the quantitative ion peak area as the ordinate (y) and the corresponding concentration as the abscissa (x). See Table 3 for details.

[0070] Table 3 Detection limit, quantification limit, linear range, linear equation and correlation coefficient of nitrofen and fluazifop-butyl

[0071]

[0072] The linearity was excellent within the specified range, with the correlation coefficient of herbicide butyl greater than 0.9936 and the correlation coefficient of fluazifop-butyl greater than 0.9925. The detection limit (LOD) of herbicide butyl was 0.020 mg / kg, and the limit of quantification (LOQ) was 0.050 mg / kg; the detection limit of fluazifop-butyl was 0.004 mg / kg, and the limit of quantification was 0.010 mg / kg.

[0073] Example 12

[0074] The blank matrices of six cosmetic categories, including essential oils (essential oils), creams and lotions (face creams), water-based products (toners), wax-based products (lipsticks), powders (loose powders), and gels (gels), were spiked at three concentration levels (LOQ, 2LOQ, and 10LOQ). Six parallel experiments were performed simultaneously at each concentration level. The average recoveries and coefficients of variation (RSD, %) are shown in Table 4.

[0075] Table 4 Average recoveries and relative standard deviations of herbicide ether and fluazifop-butyl in cosmetics with different matrices (n=6)

[0076]

[0077]

[0078] As can be seen from Table 4, the average recoveries of herbicide ether and fluazifop-butyl ranged from 81.47% to 109.87%, and the relative standard deviations (RSDs) were from 0.50% to 10.97%, both meeting the requirements of SN / T 0001-2016.

[0079] Application Examples

[0080] The detection methods of Examples 1-5 were used to test 30 cosmetic samples on the market, including toner, face cream, hand cream, shampoo, essential oil, gel, eye shadow, loose powder, and lipstick. No trace of the substance was detected in any of the samples.

[0081] Based on the disclosure and teachings of the above description, those skilled in the art may also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and any modifications and variations of the invention should also fall within the scope of protection of the claims of the present invention. In addition, although certain specific terms are used in this description, these terms are for convenience of description only and do not constitute any limitation to the invention.

Claims

1. A method for determining herbicide ether and fluazifop-butyl in cosmetics based on GC-MS, characterized in that: The following steps are involved: S1. Extraction: Mix the sample with an extraction solvent and perform ultrasonic extraction, centrifuge, and take the supernatant and perform nitrogen blowing to obtain a liquid to be purified containing the extract; the sample is an essential oil or cream cosmetic; the extraction solvent is an acetonitrile-water solution with a volume ratio of 9:1; S2, purification: the liquid to be purified in step S1 is passed through a solid phase extraction column, eluted with a mixed solution of acetone and n-hexane in a volume ratio of 4:6, the filtrate is collected, dried with nitrogen in a 45°C water bath, then dissolved with an organic solvent and fixed to volume, mixed evenly, and filtered through an organic membrane to obtain a purified liquid; the solid phase extraction column is an EMR-Lipid solid phase extraction column; S3. Detection: The purified liquid obtained in step S2 is detected and analyzed using a gas chromatography-mass spectrometer.

2. The method according to claim 1, wherein: The specific extraction steps in step S1 are: adding extraction solvent to the sample, shaking for 2-2.5 minutes to fully mix the sample and extraction solvent, extracting under ultrasound for 10-20 minutes, centrifuging at 9000-11000 r / min for 5-10 minutes, taking all the supernatant and blowing it with nitrogen to 5 mL to obtain the liquid to be purified.

3. The method according to claim 1, wherein: The specific purification steps of step S2 are as follows: all the liquid to be purified is loaded onto a solid phase extraction column, the filtrate is collected, and nitrogen is blown to near dryness in a 45°C water bath, 2 mL of ethyl acetate is added to redissolve the residue, and nitrogen is blown to near dryness in a 45°C water bath, and repeated once; finally, the volume is adjusted to 1 mL with ethyl acetate, and filtered through a 0.22 μm microporous filter membrane.

4. The method according to claim 1, wherein: The detection conditions of the gas chromatography-mass spectrometer are as follows: chromatographic column: HP-5MS capillary column, column length: 30.0 m, inner diameter: 0.25 mm, film thickness: 0.25 μm; programmed temperature: initial temperature: 100°C, hold for 2 min, increase to 230°C at a rate of 50°C / min, continue to increase to 250°C at a rate of 2°C / min, and then increase to 310°C at a rate of 30°C / min, and hold for 5 min; injection port temperature: 270°C; mass spectrometer interface temperature: 280°C; ion source temperature: 230°C; carrier gas: He, purity >99.999%, constant flow: 1.0 mL / min; injection volume: 1 μL; injection mode: pulsed splitless; ionization mode: EI; solvent delay: 5 min; mass spectrometer scanning mode: selected ion mode.

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