Method for detecting perfluorinated and polyfluoroalkyl substances in cosmetics

Abstract

The invention belongs to the technical field of analysis and detection, and discloses a method for detecting perfluorinated and polyfluoroalkyl substances in cosmetics, which comprises the following steps: (1) mixing a perfluorinated and polyfluoroalkyl substance standard solution and an isotope internal standard solution to obtain a mixed standard solution; detecting the mixed standard solution by adopting a liquid chromatograph-mass spectrometer, drawing a standard curve, and calculating to obtain a linear equation; (2) mixing a cosmetic sample with the isotope internal standard solution, adding an extracting solution, extracting, and filtering to obtain a mixed solution to be detected; detecting the mixed to-be-detected solution by adopting the liquid chromatograph-mass spectrometer to obtain a detection result, and substituting the detection result into the linear equation to obtain the content of the perfluoro and polyfluoroalkyl substances in the mixed to-be-detected solution, the perfluoro and polyfluoroalkyl substances comprise perfluorocarboxylic acid, perfluorosulfonic acid, a fluorine polymer, perfluoroalkyl ether sulfonic acid, saturated fluorine telomere acid and perfluoroether carboxylic acid.

Description

Technical Field

[0001] The present invention relates to the technical field of analytical detection, and particularly relates to a method for detecting per- and polyfluoroalkyl substances in cosmetics. Background Art

[0002] Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic organic chemicals with properties such as chemical stability, water resistance, oil and grease resistance, and heat resistance, showing extensive application potential in multiple fields. According to the EU Cosmetic Ingredients Database, PFAS has various uses in cosmetics and can be used as emulsifiers, antistatic agents, stabilizers, surfactants, film formers, viscosity regulators, etc. to enhance the performance of cosmetics.

[0003] In addition to the above as direct raw materials, PFAS may also appear in cosmetics as by-products during the processing and manufacturing of raw materials. At the same time, a large number of studies in recent years have shown that the content of PFAS in cosmetics and personal care products is relatively high. PFAS has bioaccumulative and potential toxic effects, and long-term exposure may have a negative impact on human health. For example, it may cause major diseases such as cancer, thyroid diseases, liver damage, decreased fertility, and hormone disruption. PFAS may also accumulate and amplify in the environment through the food chain, further increasing the risk of the ecosystem. In view of the potential toxicity of PFAS, governments and relevant agencies around the world are strengthening the supervision of PFAS in cosmetics and have developed a variety of detection methods. For example, multiple countries have implemented measures to restrict or ban the use of some PFAS. These regulatory measures aim to protect the safety and health of consumers while promoting the cosmetics industry to develop in a more environmentally friendly and sustainable direction.

[0004] However, most of the existing PFAS detection methods in cosmetics work well for aqueous liquid and semi-solid cosmetics, but cannot ensure the detection efficiency of PFAS in oily cosmetics and solid cosmetics with high molecular polymers as the main components. Moreover, the types of PFAS detected are relatively single, mainly targeting two traditional PFAS, namely perfluorocarboxylic acids and perfluorosulfonic acids, while novel structural types of PFAS are often overlooked. At the same time, the existing methods for detecting PFAS generally have the following disadvantages: (1) Complex operation: Traditional PFAS detection methods usually require cumbersome sample pretreatment, such as collection, extraction, concentration, washing, etc., and then testing on the instrument. The operation is relatively complex and can lead to the loss or degradation of PFAS, thus affecting the accuracy of the detection results. (2) High cost: Traditional PFAS detection methods rely on expensive instrument equipment and require professional operators to perform the operation, which increases the difficulty and cost of detection and also limits the popularization and application of the detection method. (3) Low sensitivity: Traditional PFAS detection methods cannot detect low concentrations of PFAS, restricting their effectiveness in practical applications. (4) Poor specificity: Traditional PFAS detection methods cannot accurately distinguish target PFAS from other similar compounds and are easily interfered by other substances, resulting in the accuracy of the detection results being affected. (5) Environmental pollution: Traditional PFAS detection methods are prone to generating harmful waste during the detection process, thus causing a certain degree of pollution to the environment. Therefore, there is an urgent need to develop a more efficient, accurate, reliable, environmentally friendly and easy-to-operate detection method for PFAS in cosmetics, which is of great significance for comprehensively evaluating the pollution situation of PFAS in cosmetics. Summary of the Invention

[0005] The object of the present invention is to overcome the deficiencies of the prior art and provide a method for detecting per- and polyfluoroalkyl substances in cosmetics.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] The present invention provides a method for detecting per- and polyfluoroalkyl substances in cosmetics, comprising the following steps:

[0008] (1) Mix a per- and polyfluoroalkyl substance standard solution and an isotope internal standard solution to obtain a mixed standard solution; detect the mixed standard solution using a liquid chromatography-mass spectrometry instrument, draw a standard curve and calculate to obtain a linear equation;

[0009] (2) Mix the cosmetic sample and the isotope internal standard solution, add the extraction solution, extract and filter to obtain a mixed solution to be measured; use the liquid chromatography-mass spectrometry instrument to detect the mixed solution to be measured, obtain the detection result and substitute it into the linear equation to obtain the content of perfluoro- and polyfluoroalkyl substances in the mixed solution to be measured; the perfluoro- and polyfluoroalkyl substances include perfluorocarboxylic acids, perfluorosulfonic acids, fluorinated polymers, perfluoroalkyl ether sulfonic acids, saturated fluorotelomeric acids and perfluoroether carboxylic acids; the extraction solution includes ammonia water, methanol and acetonitrile; the volume of the ammonia water is 0.05%-0.15% of the volume of the extraction solution.

[0010] As a preferred embodiment of the method for detecting perfluoro- and polyfluoroalkyl substances in the cosmetic of the present invention, the perfluorocarboxylic acids include perfluoropropionic acid, perfluorobutyric acid, perfluorovaleric acid, perfluorohexanoic acid, perfluoroheptanoic acid, perfluorooctanoic acid, perfluorononanoic acid, perfluorodecanoic acid, perfluoroundecanoic acid, perfluorododecanoic acid, perfluorotridecanoic acid, perfluorotetradecanoic acid, perfluorohexadecanoic acid, perfluoro-3-methoxypropionic acid, perfluoro-3-methoxypropionic acid; the perfluorosulfonic acids include perfluorobutane sulfonic acid, perfluoropentane sulfonic acid, perfluorohexane sulfonic acid, perfluoroheptane sulfonic acid, perfluorooctane sulfonic acid, perfluoro(2-ethoxyethane) sulfonic acid; the fluorinated polymers include 2H,2H-perfluorooctanoic acid, 2H,2H-perfluorodecanoic acid, 1H,1H,2H,2H-perfluorooctane sulfonic acid, 1H,1H,2H,2H-perfluorodecane sulfonic acid, mono[2-(perfluoroethane)ethyl] phosphate, bis[2-(perfluorohexyl)ethyl] phosphate, bis(2-(perfluoroethyl)) phosphate; the perfluoroalkyl ether sulfonic acids include perfluorooctyl sulfonamide, N-methyl perfluorooctane sulfonamide, N-methyl perfluorooctane sulfonamide acetate, N-ethyl perfluorooctane sulfonamide, N-ethyl perfluorooctane sulfonamide acetate; the saturated fluorotelomeric acids include 2H,2H,3H,3H-perfluorooctanoic acid, 2H,2H,3H,3H-perfluorohexanoic acid, 1H,1H,2H,2H-perfluorohexane sulfonic acid; the perfluoroether carboxylic acids include perfluoro(2-methyl-3-oxahexanoic acid).

[0011] The 37 PFASs in the per- and polyfluoroalkyl substances of the present invention are divided into 6 categories according to their molecular structural characteristics, including 15 perfluorocarboxylic acids (PFCAs): perfluoropropionic acid (PFPrA), perfluorobutyric acid (PFBA), perfluorovaleric acid (PFPeA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), perfluorotridecanoic acid (PFTriDA), perfluorotetradecanoic acid (PFTeDA), perfluorohexadecanoic acid (PFHxDA), perfluoro-3-methoxypropionic acid (PFMPA), perfluoro-3-methoxybutyric acid (PFMBA); 6 perfluorosulfonic acids (PFSAs): perfluorobutanesulfonic acid (PFBS), perfluoropentanesulfonic acid (PFPeS), perfluorohexanesulfonic acid (PFHxS), perfluoroheptanesulfonic acid (PFHpS), perfluorooctanesulfonic acid (PFOS), perfluoro(2-ethoxyethane)sulfonic acid (PFEESA); 7 fluorotelomer-based compounds with 6:2 and 8:2 (n:2FTs): 2H,2H-perfluorooctanoic acid (6:2FTCA), 2H,2H-perfluorodecanoic acid (8:2FTCA), 1H,1H,2H,2H-perfluorooctanesulfonic acid (6:2FTSA), 1H,1H,2H,2H-perfluorodecanesulfonic acid (8:2FTSA), mono[2-(perfluoroethyl)ethyl] phosphate (6:2PAP), bis[2-(perfluorohexyl)ethyl] phosphate (6:2diPAP), bis(2-(perfluoroethyl)) phosphate (8:2diPAP); 5 perfluoroalkylether sulfonic acids (PFESAs): perfluorooctanesulfonamide (FOSA), N-methylperfluorooctanesulfonamide (MeFOSA), N-methylperfluorooctanesulfonamide acetic acid (N-MeFOSAA), N-ethylperfluorooctanesulfonamide (EtFOSA), N-ethylperfluorooctanesulfonamide acetic acid (N-EtFOSAA); 3 saturated fluorotelomer acids (FTASs): 2H,2H,3H,3H-perfluorooctanoic acid (5:3FTCA), 2H,2H,3H,3H-perfluorohexanoic acid (3:3FTCA), 1H,1H,2H,2H-perfluorohexanesulfonic acid (4:2FTCA); 1 perfluoroether carboxylic acid (PFECAs): perfluoro(2-methyl-3-oxahexanoic acid) (HFPO-DA).

[0012] As a preferred embodiment of the method for detecting perfluoro and polyfluoroalkyl substances in the cosmetics of the present invention, the mass of the cosmetic sample is 0.05 g - 0.5 g.

[0013] Preferably, the mass of the cosmetic sample is 0.1 g - 0.2 g.

[0014] As a preferred embodiment of the method for detecting perfluoro and polyfluoroalkyl substances in the cosmetics of the present invention, the volume of the ammonia water is a range value between one or both of 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15% of the volume of the extract.

[0015] The 0.1% ammonia water - methanol / acetonitrile solution used in the present invention is the optimal test condition. The ammonia water, methanol, and acetonitrile in the extract of the present invention synergistically and significantly improve the solubility of perfluoro and polyfluorinated compounds (PFAS), making the extraction process more efficient. Especially for PFAS with stronger polarity, such as perfluorocarboxylic acid and perfluorosulfonic acid, it also shows good extraction effects on hydrophobic and medium-polarity PFAS, having wide applicability. At the same time, due to the synergistic effect of the solvent combination, the extraction efficiency can be significantly improved, and PFAS in cosmetics can be extracted more quickly and accurately.

[0016] As a preferred embodiment of the method for detecting perfluoro and polyfluoroalkyl substances in the cosmetics of the present invention, the volume ratio of the methanol to the acetonitrile is (0.5 - 1.5):1.

[0017] Preferably, the volume ratio of the methanol to the acetonitrile is 1:1.

[0018] As a preferred embodiment of the method for detecting perfluoro and polyfluoroalkyl substances in the cosmetics of the present invention, the cosmetics include at least one of aqueous liquid cosmetics, aqueous semi-solid cosmetics, and oily solid cosmetics.

[0019] As a preferred embodiment of the method for detecting perfluoro and polyfluoroalkyl substances in the cosmetics of the present invention, the cosmetics include at least one of toner, lotion, sunscreen, liquid foundation, liquid eyeliner pen, lipstick, mascara, eyebrow pencil, and eyeshadow.

[0020] As a preferred embodiment of the method for detecting perfluoro and polyfluoroalkyl substances in the cosmetics of the present invention, the extraction includes ultrasonic extraction and solid-phase extraction column extraction.

[0021] In the method for detecting perfluoro and polyfluoroalkyl substances in the cosmetics of the present invention, the combination of ultrasonic extraction and solid-phase extraction column extraction significantly improves the extraction efficiency and accuracy.

[0022] Preferably, the temperature of the ultrasonic extraction is 30°C - 50°C, and the time is 20 min - 30 min.

[0023] More preferably, the temperature of the ultrasonic extraction is one or a range value between any two of 30°C, 35°C, 40°C, 45°C, and 50°C; the time of the ultrasonic extraction is one or a range value between any two of 20 min, 25 min, and 30 min.

[0024] Preferably, the extraction column used for the solid-phase extraction column extraction is a CNWBOND Carbon-GCB SPE column.

[0025] The CNWBOND Carbon-GCB SPE solid-phase extraction cartridge used in the present invention is the optimal test condition. The packing material of the CNWBOND Carbon-GCB solid-phase extraction cartridge selected in the present invention is graphitized carbon black, which has a large specific surface area and a porous structure, and can remove impurities such as pigments, inorganic compounds, and metal ions in cosmetics. In addition, the carbon atoms on the surface of graphitized carbon black are sp 2 hybridized, and can have a strong affinity with impurities with weak hydrophobicity, strong polarity or hydrogen bond donors in cosmetics through van der Waals forces, hydrogen bonds, etc., effectively removing impurities in cosmetics and reducing the matrix effect. Compared with ion-exchange solid-phase extraction cartridges such as HLB solid-phase extraction columns, WAX solid-phase extraction columns, and WCX solid-phase extraction columns, it is more suitable for purifying excipients such as inorganic substances, fragrances, pigments, surfactants, and polymers in cosmetic matrices, reducing the matrix effect, and improving the detection efficiency.

[0026] Preferably, the activation solution for the solid-phase extraction column extraction includes ammonia water, methanol, and acetonitrile; the volume of the ammonia water is 0.05% - 0.15% of the volume of the activation solution.

[0027] More preferably, the volume of the ammonia water is one or a range value between any two of 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, and 0.15% of the volume of the activation solution.

[0028] Preferably, the volume ratio of the methanol to the acetonitrile is 1:1.

[0029] Preferably, the eluent for the solid-phase extraction column extraction includes ammonia water, methanol, and acetonitrile; the volume of the ammonia water is 0.05% - 0.15% of the volume of the eluent.

[0030] Further preferably, the volume of the ammonia water is in the range of one or both values among 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15% of the volume of the eluent.

[0031] Preferably, the volume ratio of the methanol to the acetonitrile is 1:1.

[0032] As a preferred embodiment of the method for detecting perfluoro and polyfluoroalkyl substances in the cosmetic of the present invention, the concentration of the isotope internal standard solution is 20 μg / L - 30 μg / L.

[0033] Preferably, the concentration of the isotope internal standard solution is 25 μg / L.

[0034] As a preferred embodiment of the method for detecting perfluoro and polyfluoroalkyl substances in the cosmetic of the present invention, the concentration of the perfluoro and polyfluoroalkyl substances in the mixed standard solution is 1 μg / L - 100 μg / L.

[0035] As a preferred embodiment of the method for detecting perfluoro and polyfluoroalkyl substances in the cosmetic of the present invention, the isotope internal standard solution includes perfluorobutyric acid- 13 C4, perfluorohexanoic acid- 13 C2, perfluorooctanoic acid- 13 C4, perfluorononanoic acid- 13 C5, perfluorodecanoic acid- 13 C2, perfluoroundecanoic acid- 13 C2, perfluorododecanoic acid- 13 C2, sodium perfluorohexanesulfonate- 18 O2, sodium perfluorooctanesulfonate- 13 C4, perfluoro(2-methyl-3-oxahexanoic acid)- 13 C3, bis[2-(perfluorohexyl)ethyl] phosphate- 13 C4.

[0036] As a preferred embodiment of the method for detecting perfluoro and polyfluoroalkyl substances in the cosmetic of the present invention, the filtration is carried out using a polypropylene filter membrane with a pore size of 0.22 μm.

[0037] As a preferred embodiment of the method for detecting perfluoro and polyfluoroalkyl substances in the cosmetic of the present invention, the detection conditions of the liquid chromatography - mass spectrometry instrument are as follows:

[0038] The chromatographic conditions are as follows:

[0039] Chromatographic column: ZORBAX RRHD Eclipse C18; Mobile phase A: Ammonium acetate; Mobile phase B: Acetonitrile; Flow rate: 0.2 mL / min - 0.5 mL / min; Column temperature: 30 °C - 45 °C; Elution mode: Gradient elution;

[0040] The mass spectrometry conditions are as follows:

[0041] Ion source: Electrospray ionization source (ESI); Monitoring mode: Multiple reaction monitoring mode; Drying gas flow rate: 6 L / min - 10 L / min, Drying gas temperature: 280 °C - 320 °C.

[0042] Preferably, the detection conditions of the liquid chromatography - mass spectrometry instrument are:

[0043] The chromatographic conditions are as follows:

[0044] Chromatographic column: ZORBAX RRHD Eclipse C18; Mobile phase A: Ammonium acetate; Mobile phase B: Acetonitrile; Flow rate: 0.35 mL / min; Column temperature: 40 °C; Elution mode: Gradient elution;

[0045] The mass spectrometry conditions are as follows:

[0046] Ion source: Electrospray ionization source (ESI); Monitoring mode: Multiple reaction monitoring mode; Drying gas flow rate: 8 L / min, Drying gas temperature: 300 °C.

[0047] Preferably, the concentration of the ammonium acetate is 3 mmol / L - 8 mmol / L.

[0048] More preferably, the concentration of the ammonium acetate is one of 3 mmol / L, 4 mmol / L, 5 mmol / L, 6 mmol / L, 7 mmol / L, 8 mmol / L or a range value between any two of them.

[0049] As a preferred embodiment of the method for detecting perfluoro and polyfluoroalkyl substances in the cosmetic of the present invention, the gradient elution program is: Taking the elution time as T, 0 ≤ T < 1 min, the volume fraction of mobile phase B is 10%; 1 ≤ T < 3 min, the volume fraction of mobile phase B is 10% - 30%; 3 ≤ T < 5 min, the volume fraction of mobile phase B is 30% - 45%; 5 ≤ T < 10 min, the volume fraction of mobile phase B is 45% - 70%; 10 ≤ T < 15 min, the volume fraction of mobile phase B is 70% - 95%; 15 ≤ T < 17 min, the volume fraction of mobile phase B is 95%; 17.01 ≤ T < 19.5 min, the volume fraction of mobile phase B is 95% - 10%; 19.5 min, the volume fraction of mobile phase B is 10%.

[0050] Compared with the prior art, the beneficial effects of the present invention are as follows: First, the detection method of per- and polyfluoroalkyl substances in the cosmetics of the present invention establishes a pretreatment method for extracting per- and polyfluoroalkyl substances in cosmetics, which can effectively extract cosmetics with different properties, and realizes the rapid qualitative and quantitative determination of 6 molecular structure types (37 kinds) of per- and polyfluoroalkyl substances, both traditional and emerging, in cosmetics. The detection method has good linearity within the detection range (linear correlation coefficient is greater than 0.99), which means that the method of the present invention can accurately determine the content of per- and polyfluoroalkyl substances within a wide concentration range and is applicable to the detection of per- and polyfluoroalkyl substances in cosmetics with different properties. At the same time, the method of the present invention has good stability, and the detection limit is 0.2 pg / g - 953.0 pg / g; this means that the method of the present invention can detect per- and polyfluoroalkyl substances at very low concentrations and also has high sensitivity to trace per- and polyfluoroalkyl substance pollution in the environment. In addition, the method of the present invention can reduce interference during the detection process and improve the accuracy and reliability of the detection. This is crucial for ensuring the accuracy and reliability of the detection results. Therefore, the method for detecting per- and polyfluoroalkyl substances of the present invention is an efficient, accurate, and reliable method for detecting per- and polyfluoroalkyl substances, and has broad application prospects in the fields of environmental monitoring, cosmetics safety, etc. Description of the Drawings

[0051] Figure 1 It is the total ion current (TIC) diagram for the detection of isotope internal standards in the cosmetic matrix of the present invention;

[0052] Figure 2 It is the chromatogram of per- and polyfluoroalkyl substances detected in different types of cosmetic samples of the present invention. Detailed Embodiments

[0053] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0054] The following is elaborated in conjunction with specific embodiments to illustrate the actual effects of the solution of the present invention.

[0055] Unless otherwise specified, the test methods used in the embodiments are all conventional methods; the materials, reagents, equipment, etc. used, unless otherwise specified, can all be obtained from commercial channels.

[0056] The instruments and reagents used in the examples and comparative examples of the present invention are as follows:

[0057] Instruments: Agilent 1290 Infinity II ultra-high performance liquid chromatography (UHPLC) tandem 6470 triple quadrupole mass spectrometry (QQQ-MS / MS), equipped with an AJS electrospray ionization source (AJS-ESI) and an atmospheric pressure chemical ionization source (APCI); analytical balance (Mettler, USA); nitrogen evaporator (LabTech MV5); vortex oscillator (Vortex-Genie 2), solid phase extraction device (SUPELCO VISIPREP 24 TM DL); ultrasonic cleaner (Elma, Germany); high-speed refrigerated centrifuge (Thermo Fisher, Germany).

[0058] Reagents: methanol (LC / MS grade), acetonitrile (LC / MS grade), acetone (LC / MS grade), 25% ammonia water (LC / MS grade), formic acid (LC / MS grade), Milli-Q water.

[0059] Ammonia-methanol / acetonitrile solution: Take 1 mL of ammonia water (LC / MS grade) and dilute it to 1 L with a methanol / acetonitrile mixed solution with a volume ratio of 1:1 to obtain a 0.1% (v:v) ammonia-methanol / acetonitrile solution.

[0060] Steroid hormone standards: including PFCAs, PFSAs, n:2FTs, PFESAs, FTASs, PFECAs in Table 1, and isotope internal standards, with a purity greater than 95%. The isotope internal standards were purchased from Wellington Laboratories and ANPEL, and the PFAS analysis standards were purchased from DR. Ehrenstorfer GmbH, First Standard, Beijing Tanmo Quality Inspection Technology Co., Ltd., and Guangzhou Jiantu Technology Co., Ltd.

[0061] Table 1: Mass spectrometry parameters of PFAS and isotope internal standards

[0062]

[0063]

[0064]

[0065] Example 1: Detection method for PFAS concentration in cosmetics

[0066] 1. Preparation of standard solutions

[0067] (1) Weigh accurately 11 isotope internal standards respectively and prepare a mixed internal standard solution with a concentration of 25 μg / L for each isotope internal standard using a solvent.

[0068] (2) Accurately weigh 37 target PFAS standards respectively, and prepare a mixed standard solution with a concentration of 10 mg / L for each PFAS standard using a solvent.

[0069] (3) Pipette different volumes of the mixed standard solution, add 100 μL of the mixed internal standard solution respectively, and dilute with a solvent to obtain a series of mixed standard solutions with concentrations of 1 μg / L, 5 μg / L, 20 μg / L, 50 μg / L, and 100 μg / L for each target PFAS.

[0070] 2. Sample treatment (pretreatment)

[0071] (1) Treat water-based liquid and semi-solid cosmetics: Weigh 0.2 g of sunscreen, liquid foundation, liquid eyeliner pen, shaving foam, lipstick, and mascara samples respectively into 15 mL polypropylene centrifuge tubes, add 100 μL of 25 μg / L isotope internal standards (11 kinds), add 5 mL of 0.1% ammonia-methanol / acetonitrile (1:1) mixed extraction solution, place it on a vortex mixer and vortex at 2000 rpm for 5 min, ultrasonically extract at 40 °C for 20 min, then centrifuge at 10000 r / min for 15 min, and extract the supernatant. Repeat the above operations, combine the supernatants, and collect a total of 10 mL of supernatant. Adjust the pH value to 6 - 7 with 2% formic acid. Activate the CNWBOND Carbon-GCB SPE (100 mg, 1 mL) solid-phase extraction cartridge with 3 mL of 0.1% ammonia-methanol / acetonitrile (1:1), pass the extract through the cartridge and collect it, then wash the cartridge with 2 mL of 0.1% ammonia-methanol / acetonitrile (1:1) solution and collect it. Combine the purified solutions to a total of 12 mL. Control the flow rate at 1 drop / s during the purification process. Keep the solid-phase extraction cartridge moist during activation and passing the column. When collecting the eluate, fully drain it. Place the purified solution in a nitrogen evaporator and evaporate it to nearly dryness, redissolve it in methanol to 100 μL, filter it through a 0.22 μm polypropylene syringe filter to obtain the sample solution to be measured, collect it in a 0.3 mL polypropylene injection vial, and store it at -20 °C for further measurement. Set 3 process blanks for each group of experiments, and use the same treatment method as the samples to identify and quantify the possible contamination introduced during sample treatment and analysis, and ensure the accuracy and reliability of the analysis results.

[0072] (2) Treatment of oily cosmetics and solid cosmetics with high molecular polymers as the main components: Weigh 0.2 g of lipstick, mascara, eyebrow pencil, and eyeshadow samples into 15 mL polypropylene centrifuge tubes respectively, add 100 μL of 25 μg / L isotope internal standards (11 kinds), add 1 mL of acetone, and shake the resulting mixture on a horizontal shaker at 350 rpm and 40 °C for 20 min. Then add 5 mL of 0.1% ammonia-methanol / acetonitrile (1:1) mixed extraction solution, vortex at 2000 rpm for 5 min on a vortex mixer, and perform ultrasonic extraction at 40 °C for 25 min. The subsequent treatment steps are the same as those in sample treatment step (1).

[0073] 3. Use an ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS / MS) instrument for detection

[0074] (1) Mass spectrometry analysis conditions: For 6 types of PFAS, an electrospray ionization source (ESI) is used, the detection mode is negative ion mode (ESI-), the mass spectrometry detection uses multiple reaction monitoring mode (MRM), the dryer flow rate is 8 L / min, the dryer temperature is 300 °C, the nebulizer pressure is 45 Psi, the sheath gas temperature is 325 °C, the flow rate is 12 L / min, and the nozzle voltage is 1000 V. The main mass spectrometry parameters are shown in Table 1.

[0075] (2) UPLC liquid phase conditions: Select a ZORBAX RRHD Eclipse C18 column (3 mm × 10 mm × 1.8 μm), and the mobile phase uses 5 mmol / L ammonium acetate (A) and acetonitrile (B); Mobile phase gradient: 0 - 1 min, 10% B phase; 1 - 3 min, B phase increases to 30%; 3 - 5 min, B phase increases to 45%; 5 - 10 min, B phase increases to 70%; 10 - 15 min, B phase increases to 95%; 15 - 17 min, 95% B is maintained for 2 min; 17 - 17.01 min, B phase drops to 10%; 19.5 min, 10% B. The flow rate is 0.35 mL / min, the column temperature is set at 40 °C, and the injection volume is 5 μL; During each experiment, a process blank and an instrument blank are set to monitor the blank interference caused during the experimental operation and the instrument detection process. The injection vials and caps selected do not contain fluorides.

[0076] (3) Use the test conditions of the above ultra-high performance liquid chromatography-tandem mass spectrometry instrument to perform UPLC-MS analysis on the series of mixed standard solutions obtained in step 1. Perform linear regression analysis using the ratio (x) of the peak area of each target compound to the peak area of the internal standard and the concentration ratio (y) of each target compound to the internal standard to obtain the standard curve and linear equation.

[0077] (4) Performing UPLC-MS analysis on the sample solution obtained in step 2 using the test conditions of the above-mentioned ultra-high performance liquid chromatography-tandem mass spectrometry instrument, and then calculating the content of the target substance in the sample solution according to the peak area ratios of the 37 target substances in the sample solution to the internal standard substance according to their respective standard working curves.

[0078] 4. Assessment parameters and results of the method

[0079] The present invention adopts a high performance liquid chromatography-mass spectrometry method. In the ion detection mode (MRM), for each PFAS, two MRM ion pairs with high intensity and strong stability are selected, and the declustering voltage and collision energy are optimized; the two pairs of MRM ion pairs are used for qualitative analysis at the same time, and the ion pairs with higher signal response are used for quantitative analysis, thereby establishing a negative ion mode acquisition method.

[0080] (1) Qualitative analysis: Each PFAS is confirmed by retention time and two pairs of ion pairs (see Table 1) to determine the presence of the target compound in the sample.

[0081] (2) Quantitative analysis: The present invention adopts the internal standard method to calculate the content of the target substance in the test sample according to the peak area ratio of the 37 target substances in the test sample solution to the internal standard substance according to the respective standard working curves.

[0082] (3) Use the corresponding isotope internal standard to correct the loss of the target substance during sample preparation and instrument analysis, and to compensate for the difference between needles during the injection process.

[0083] The specific parameters are as follows:

[0084] (i) Determination of absolute recovery and matrix effect: Since PFAS is widely detected in cosmetics, blank matrices of cosmetics with different properties cannot be obtained. Therefore, PFAS isotope internal standards are added to various types of cosmetics to replace PFAS with corresponding structures to evaluate their recovery and matrix effect in various types of cosmetics. 2.5 ng of PFAS isotope standard was added before and after extraction of 0.2 g of blank cosmetic samples. The absolute recovery was calculated by the peak area ratio, and the matrix effect was calculated by the ratio of the peak area after extraction to the peak area of ​​the standard pure solution. The results showed that in various types of cosmetic matrices, the absolute recovery of PFAS isotope internal standards was 70%-117%, and the matrix effect was 82%-105%.

[0085] (ii) Determination of standard curve and minimum method quantitation limit: Prepare the mixed standard solution according to the method in step (1) and perform UPLC-MS analysis, and perform quantitative calculation using the internal standard method. Perform linear regression analysis with the ratio (x) of the peak area of each target compound to the peak area of the internal standard and the concentration ratio (y) of each target compound to the internal standard to obtain the standard curve and linear equation. The results show that there is a good linear relationship between the concentration ratio of the substance to the corresponding internal standard and the peak area ratio, and the correlation coefficient (R 2 ) is greater than 0.99. The ranges of the minimum method detection limit (MDL) and quantitation limit (MQL) of each PFAS are calculated based on the signal-to-noise ratio (S / N) and concentration factor to be 0.2 pg / g - 953.0 pg / g and 0.7 pg / g - 3177.0 pg / g, respectively.

[0086] Table 2: PFAS-related method parameters

[0087]

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for detecting per- and polyfluoroalkyl substances in cosmetics, characterized in that, It includes the following steps: (1) Mix the perfluoro and polyfluoroalkyl substance standard solution and the isotope internal standard solution to obtain a mixed standard solution; use a liquid chromatography-mass spectrometry (LC-MS) instrument to detect the mixed standard solution, draw a standard curve and calculate to obtain a linear equation; (2) Mix the cosmetic sample and the isotope internal standard solution, add an extraction solution, extract and filter to obtain a mixed test solution; use the LC-MS instrument to detect the mixed test solution, obtain the detection result and substitute it into the linear equation to obtain the content of perfluoro and polyfluoroalkyl substances in the mixed test solution; the perfluoro and polyfluoroalkyl substances include perfluorocarboxylic acids, perfluorosulfonic acids, fluorinated polymers, perfluoroalkyl ether sulfonic acids, saturated fluorotelomeric acids and perfluoroether carboxylic acids; the extraction solution includes ammonia water, methanol and acetonitrile; the volume of the ammonia water is 0.05%-0.15% of the volume of the extraction solution.

2. The detection method of perfluorinated and polyfluorinated alkyl substances in cosmetics according to claim 1, characterized in that, The perfluorocarboxylic acids include perfluoropropionic acid, perfluorobutyric acid, perfluorovaleric acid, perfluorohexanoic acid, perfluoroheptanoic acid, perfluorooctanoic acid, perfluorononanoic acid, perfluorodecanoic acid, perfluoroundecanoic acid, perfluorododecanoic acid, perfluorotridecanoic acid, perfluorotetradecanoic acid, perfluorohexadecanoic acid, perfluoro-3-methoxypropionic acid, perfluoro-3-methoxypropionic acid; the perfluorosulfonic acids include perfluorobutane sulfonic acid, perfluoropentane sulfonic acid, perfluorohexane sulfonic acid, perfluoroheptane sulfonic acid, perfluorooctane sulfonic acid, perfluoro(2-ethoxyethane) sulfonic acid; the fluorinated polymers include 2H,2H-perfluorooctanoic acid, 2H,2H-perfluorodecanoic acid, 1H,1H,2H,2H-perfluorooctane sulfonic acid, 1H,1H,2H,2H-perfluorodecane sulfonic acid, mono[2-(perfluoroethane)ethyl] phosphate, bis[2-(perfluorohexyl)ethyl] phosphate, bis(2-(perfluoroethyl)) phosphate; the perfluoroalkyl ether sulfonic acids include perfluorooctyl sulfonamide, N-methyl perfluorooctane sulfonamide, N-methyl perfluorooctane sulfonamide acetic acid, N-ethyl perfluorooctane sulfonamide, N-ethyl perfluorooctane sulfonamide acetic acid; the saturated fluorotelomeric acids include 2H,2H,3H,3H-perfluorooctanoic acid, 2H,2H,3H,3H-perfluorohexanoic acid, 1H,1H,2H,2H-perfluorohexane sulfonic acid; the perfluoroether carboxylic acids include perfluoro(2-methyl-3-oxahexanoic acid).

3. The detection method of perfluorinated and polyfluorinated alkyl substances in cosmetics according to claim 1, characterized in that, The volume of the ammonia water is 0.1% of the volume of the extraction solution.

4. The method for detecting perfluoro and polyfluoroalkyl substances in cosmetics according to claim 1, wherein The extraction includes ultrasonic extraction and solid-phase extraction column extraction.

5. The method for detecting perfluoro and polyfluoroalkyl substances in cosmetics according to claim 4, characterized in that, The temperature of the ultrasonic extraction is 30°C - 50°C, and the time is 20 min - 30 min.

6. The detection method of perfluorinated and polyfluorinated alkyl substances in cosmetics according to claim 1, characterized in that, The extraction column used for the solid-phase extraction column extraction is the CNWBOND Carbon-GCB SPE column.

7. The detection method of perfluoro and polyfluoroalkyl substances in cosmetics according to claim 1, characterized in that, The concentration of the isotope internal standard solution is 20 μg / L - 30 μg / L.

8. The detection method of perfluorinated and polyfluorinated alkyl substances in cosmetics according to claim 1, characterized in that, The detection conditions of the liquid chromatography-mass spectrometry (LC-MS) instrument are as follows: The chromatographic conditions are as follows: Chromatographic column: ZORBAX RRHD Eclipse C18; Mobile phase A: Ammonium acetate; Mobile phase B: Acetonitrile; Flow rate: 0.2 mL / min - 0.5 mL / min; Column temperature: 30°C - 45°C; Elution method: Gradient elution; The mass spectrometry conditions are as follows: Ion source: Electrospray ionization source (ESI); Monitoring mode: Multiple reaction monitoring mode; Drier flow rate: 6 L / min - 10 L / min, drier temperature: 280 °C - 320 °C.

9. The method for detecting per- and polyfluoroalkyl substances in cosmetics according to claim 8, wherein, The concentration of the ammonium acetate is 3 mmol / L - 8 mmol / L.

10. The method for detecting perfluoro and polyfluoroalkyl substances in cosmetics according to claim 8, characterized in that, The program of the gradient elution is as follows: Taking the elution time as T, when 0 ≤ T < 1 min, the volume fraction of mobile phase B is 10%; when 1 ≤ T < 3 min, the volume fraction of mobile phase B is 10% - 30%; when 3 ≤ T < 5 min, the volume fraction of mobile phase B is 30% - 45%; when 5 ≤ T < 10 min, the volume fraction of mobile phase B is 45% - 70%; when 10 ≤ T < 15 min, the volume fraction of mobile phase B is 70% - 95%; when 15 ≤ T < 17 min, the volume fraction of mobile phase B is 95%; when 17.01 ≤ T < 19.5 min, the volume fraction of mobile phase B is 95% - 10%; At 19.5 min, the volume fraction of mobile phase B is 10%.

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