Method for detecting forbidden colorants in cosmetic products

Abstract

The application provides a method for simultaneously detecting multiple forbidden colorants in cosmetics, comprising: sample preparation, dissolving the cosmetic to be detected in an extraction agent, centrifuging to obtain supernatant, filtering through a microporous filter to obtain the sample to be detected; using the extraction agent as a blank control solution; sample detection, detecting the sample to be detected by using a liquid chromatograph, and quantitatively analyzing the colorants in the sample by using a standard curve method; and calculating the content of the colorants in the cosmetic. The application can simultaneously detect the contents of multiple forbidden colorants in cosmetics, and the detection method is simple and easy to operate.

Description

Technical Field

[0001] This invention relates to the field of analytical chemistry, and more specifically to a method for detecting prohibited colorants in cosmetics. Background Technology

[0002] Colorants in cosmetics are substances added to cosmetics to give them color by utilizing the principle of absorbing or reflecting visible light. Colorants are divided into natural and synthetic colorants. However, natural colorants are expensive, have poor stability, and produce uneven coloring, while synthetic colorants are widely used due to their strong coloring power, bright colors, resistance to fading, stability, easy solubility, and low cost. However, most synthetic colorants pose certain safety risks to human health; some are sensitizing, have reproductive and developmental toxicity, and a few have carcinogenic risks. Currently, China's "Cosmetic Safety Technical Specifications" (2015 edition) explicitly prohibits the use of 47 colorants in cosmetics in its 2021 revised "List of Prohibited Raw Materials in Cosmetics"; the European Union (EC) Regulation 1223 / 2009, "Cosmetics Regulation of the European Parliament and the Council of the European Union," also stipulates 42 prohibited colorants in cosmetics.

[0003] According to literature reports, 10% of lipsticks on the market contain prohibited colorants, and nearly 10% of hair dye cosmetics have problems with the illegal use of prohibited dyes and colorants. Therefore, the use of colorants in cosmetics in my country needs further regulation, and the supervision of prohibited colorants urgently needs to be strengthened. However, currently, my country's testing standards for prohibited colorants in cosmetics are incomplete; existing standards cannot cover the testing of all prohibited colorants, undoubtedly placing enormous pressure on cosmetic supervision. Domestic testing standards for prohibited colorants in cosmetics mainly include GB / T 30927-2014, GB / T 34806-2017, and SN / T 4575-2016, covering a total of 14 prohibited colorants in cosmetics, less than one-third of the total number of prohibited colorants. There is still a situation where many prohibited colorants lack testing standards, posing a significant challenge to the current supervision of prohibited colorants in cosmetics. Therefore, further improving and supplementing the testing standards for prohibited colorants in cosmetics is imperative.

[0004] Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 are colorants that have gained attention in recent years, attracting considerable interest from the market and research teams. They are mainly used in the plastics, textiles, and ink industries, and are all prohibited substances in cosmetics under the regulations of my country and the European Union. Currently, there are no corresponding detection methods for Solvent Yellow 44 and Solvent Black 5, while research on detection methods for Disperse Orange 3 mainly focuses on textiles, toys, and related fields. Furthermore, there are currently no detection standards for Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 in cosmetics, both domestically and internationally. Therefore, it is urgent to conduct research and standardization work on detection methods for Disperse Orange 3, Solvent Yellow 44, and Solvent Black 5 in different types of cosmetics. Establishing industry standards for Disperse Orange 3, Solvent Yellow 44, and Solvent Black 5 in cosmetics will fill the gap in detection standards, improve and enhance the customs laboratory's detection capabilities for prohibited colorants in imported and exported cosmetics, and provide strong technical support for strengthening customs laboratory supervision of imported and exported cosmetics.

[0005] Currently, there are three main standards for the detection of Disperse Orange 3, primarily focusing on its determination in the food and textile industries. Most of the retrieved literature addresses the detection of Disperse Orange 3 in textiles, toys, and food. A small number of studies focus on the detection of Disperse Orange 3 in nail polish, but their sample matrix coverage is insufficient. Due to the complexity and variety of cosmetic matrices, the methods described in the above standards and literature cannot be directly applied to the detection of Disperse Orange 3 in cosmetics. Therefore, the existing standards and literature are irrelevant to this invention. Currently, there are no standard detection methods, either domestically or internationally, for the content of Disperse Orange 3, Solvent Yellow 44, and Solvent Black 5 in cosmetics. Summary of the Invention

[0006] To address the shortcomings of the prior art, this invention provides a method for detecting prohibited colorants such as Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 in cosmetics, thereby solving the problems in the prior art.

[0007] To achieve the above and other related objectives, the present invention provides a method for detecting colorants in cosmetics.

[0008] The first aspect of this invention provides a method for detecting prohibited colorants in cosmetics, the method comprising:

[0009] 1) Sample preparation: Weigh the cosmetic sample to be tested into a centrifuge tube, add the extractant, vortex to mix, sonicate, and centrifuge; take the supernatant, dilute to volume with the extractant, and filter through a microporous membrane to obtain the sample solution to be tested; or directly use the extractant, vortex to mix, sonicate, and centrifuge; take the supernatant, dilute to volume with the extractant, and filter through a microporous membrane to obtain the blank solution.

[0010] 2) Sample detection: The sample to be tested was detected using a liquid chromatograph, and the colorant in the sample was quantitatively analyzed using the standard curve method;

[0011] 3) Calculation of the content of prohibited colorants in cosmetics.

[0012] Preferably, the colorant is one or more of Solvent Yellow 44, Disperse Orange 3, or Solvent Black 5.

[0013] Preferably, the cosmetic is selected from one or more of nail polish, eyeshadow, shampoo, hair dye, or lipstick.

[0014] Preferably, the extractant is selected from one or more of methanol, acetonitrile, or tetrahydrofuran.

[0015] More preferably, when extracting from nail polish, hair dye, eyeshadow, or shampoo, the extractant is selected from one or both of methanol and acetonitrile; when extracting from lipstick, the extractant is a mixture of tetrahydrofuran and methanol; the volume ratio of tetrahydrofuran to methanol is 1:(3~5), such as 1:3, 1:4, or 1:5; more preferably, the volume ratio is 1:4. The extractant needs to have good solubility for the target colorant while also not affecting the peak elution of the target colorant during detection. The colorant stock solution prepared using the extractant in this invention showed no significant degradation after being stored at -20°C in the dark for one month.

[0016] Preferably, in step 1), based on 0.1g of the cosmetic sample to be tested, the amount of extractant added is 1~5mL, such as 1mL, 2mL, 3mL, 4mL or 5mL. More preferably, the amount of extractant added is 5mL.

[0017] Preferably, in step 1), based on 0.1g of the cosmetic sample to be tested, the volume for final determination is 5-10mL, such as 5mL, 6mL, 7mL, 8mL, 9mL, or 10mL. More preferably, the volume for final determination is 5mL.

[0018] Preferably, if a paste-like sample cannot be dispersed by vortexing, it can be heated appropriately in a water bath at 70-80℃ for 1-2 minutes.

[0019] Preferably, the ultrasonic temperature is 20~60℃, such as 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃ or 60℃.

[0020] Preferably, the ultrasound time is 20-40 minutes, such as 20 minutes, 25 minutes, 30 minutes, 35 minutes or 40 minutes.

[0021] Preferably, the centrifugation speed is 6000 r / min to 8000 r / min, such as 6000 r / min, 6500 r / min, 7000 r / min, 7500 r / min or 8000 r / min. More preferably, the centrifugation speed is 6000 r / min.

[0022] Preferably, the centrifugation time is 10-15 min, such as 10 min, 11 min, 12 min, 13 min, 14 min, or 15 min. More preferably, the centrifugation time is 10 min.

[0023] Preferably, the pore size of the microporous filter membrane is 0.20~0.50μm, such as 0.20μm, 0.22μm, 0.25μm, 0.30μm, 0.35μm, 0.40μm, 0.45μm, or 0.50μm. More preferably, the pore size of the filter membrane is 0.45μm.

[0024] Preferably, the detection conditions of the liquid chromatograph include:

[0025] 1) The chromatographic column is a C18 column;

[0026] 2) The column temperature is 30~40℃, such as 30℃, 32℃, 34℃, 36℃, 38℃ or 40℃; more preferably, the column temperature is 30℃;

[0027] 3) The injection volume is 10~20μL, such as 10μL, 12μL, 14μL, 16μL, 18μL or 20μL; more preferably, the injection volume is 10μL;

[0028] 4) The flow rate is 0.7~1.2 mL / min, such as 0.7 L / min, 0.8 mL / min, 0.9 mL / min, 1.0 mL / min, 1.1 mL / min or 1.2 mL / min, more preferably, the flow rate is 1.0 mL / min;

[0029] 5) Mobile phase: Phase A: 15~20 mmol / L ammonium acetate aqueous solution, Phase B: methanol; more preferably, Phase A is 20 mmol / L ammonium acetate aqueous solution;

[0030] 6) Detection wavelengths are 435nm and 567nm;

[0031] 7) Elution method: Gradient elution, including: Initial solvent composition: 65%~70% A phase and 30%~35% B phase, 0~4 min maintain 65%~70% A phase, 4~5 min the proportion of A phase decreases linearly to 15~20%, 5~9 min maintain 15~20% A phase, 9~10 min the proportion of A phase decreases linearly to 5%~8%, 10~16 min maintain 5%~8% A phase, 16 min~16.1 min the proportion of A phase increases linearly to 65%~70%, 16.1 min~21 min maintain 65%~70% A phase.

[0032] More preferably, the gradient elution procedure is as follows:

[0033]

[0034] Preferably, the C18 column has a packing particle size of 5 μm and a column size of 4.6 mm × 150 mm, or a chromatographic column with equivalent performance.

[0035] Preferably, the detection employs a diode array detector, performing simultaneous dual-wavelength detection at wavelengths of 435 nm and 567 nm.

[0036] The absorption wavelengths of Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 were investigated using a full-scan mode (190-900 nm). The maximum absorption wavelength of Disperse Orange 3 was found to be around 435 nm; the maximum absorption wavelength of Solvent Yellow 44 was around 204 nm, followed by 434 nm. Due to significant solvent interference and baseline fluctuations near the 204 nm absorption wavelength, this wavelength was discarded. Since the maximum absorption wavelength of Disperse Orange 3 (435 nm) is similar to that of Solvent Yellow 44 (434 nm), and measurements showed little difference in peak shape and area at 434 nm and 435 nm, 435 nm was chosen as the detection wavelength for both Solvent Yellow 44 and Disperse Orange 3, considering the convenience of the testing method. For Solvent Black 5 standard solution, the peak area at 292 nm and 567 nm was similar, but more impurity peaks were observed at 292 nm. Therefore, 567 nm was chosen as the detection wavelength for Solvent Black 5.

[0037] Preferably, the concentration of the standard solution selected in the establishment of the standard curve in the standard curve method is 0.2~100 μg / mL.

[0038] Furthermore, the standard solution concentration for the standard curve of Solvent Yellow 44 or Disperse Orange 3 can be 0.2~100.0 μg / mL, such as 0.2 μg / mL, 0.5 μg / mL, 1.0 μg / mL, 2.0 μg / mL, 5.0 μg / mL, 10.0 μg / mL, 20.0 μg / mL, 40.0 μg / mL, 60.0 μg / mL, 80.0 μg / mL or 100.0 μg / mL.

[0039] Furthermore, the standard solution concentration selected in the establishment of the standard curve for Solvent Black 5 is 1~100 μg / mL, such as 1 μg / mL, 2.5 μg / mL, 5.0 μg / mL, 10.0 μg / mL, 25.0 μg / mL, 50.0 μg / mL, 75.0 μg / mL or 100.0 μg / mL.

[0040] Preferably, in step 3), the content of colorant in the cosmetic sample is calculated according to the following formula:

[0041] .

[0042] X i The content of the target substance in the sample, expressed in milligrams per kilogram (mg / kg);

[0043] c i : The concentration of the target analyte in the sample solution obtained from the standard curve, in micrograms per milliliter (μg / mL).

[0044] c i0 : The concentration of the target substance in the blank solution obtained from the standard curve, in micrograms per milliliter (μg / mL);

[0045] V: Sample detection volume, in milliliters (mL);

[0046] S: Dilution factor. When the concentration of colorant in the sample solution exceeds the detection range of the standard curve, the sample solution is diluted. When it is not diluted, S is 1.

[0047] m: Mass of the sample corresponding to the detection volume, in grams (g).

[0048] A blank solution is introduced to calculate the colorant content in cosmetic samples to prevent detection errors caused by reagents or operations during sample preparation, thus making the detection results more accurate.

[0049] Preferably, when the detection method is used for quantitative detection, the absolute value of the matrix effect of the cosmetic is <5%, which is a weak matrix effect.

[0050] Preferably, the detection method detects a spiked recovery rate of 80% to 110% for colorants in cosmetic matrix, such as 80%, 85%, 90%, 95%, 100%, 105%, or 110%.

[0051] Preferably, the detection method has a precision of 0.1% to 5.5% for detecting colorants in a cosmetic matrix, such as 0.1%, 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, or 5.5%. More preferably, the precision is 0.11% to 5.2%.

[0052] A second aspect of this invention discloses the use of the above method for detecting prohibited colorants in cosmetics.

[0053] As described above, the beneficial effects of the present invention are as follows:

[0054] A high-performance liquid chromatography (HPLC) method was established for the simultaneous detection of Disperse Orange 3, Solvent Yellow 44, and Solvent Black 5 in cosmetics. Under the condition that the limits of quantitation (LOQ) for Disperse Orange 3 and Solvent Yellow 44 meet the requirement of 10 mg / kg, and the LQ for Solvent Black 5 meets the requirement of 50 mg / kg, the test method of this application showed the following results: a spiked recovery rate of 80%–110% and a precision of 0.11%–5.2% for Solvent Yellow 44; a spiked recovery rate of 80%–110% and a precision of 0.41%–3.8% for Disperse Orange 3; and a spiked recovery rate of 84%–107% and a precision of 1.2%–4.1% for Solvent Black 5. The target analytes in the standard solution did not show significant degradation within one month of storage at -20℃ in the dark, and all indicators met the requirements of SN / T 0001. This invention provides a simple and easy-to-operate detection method with good accuracy, improving the detection method for prohibited colorants in cosmetics and providing strong technical support for the regulation of cosmetics. Attached Figure Description

[0055] Figure 1 The liquid chromatograms are for the standards Solvent Yellow 44 and Disperse Orange 3.

[0056] Figure 2 This is the liquid chromatogram of the standard solvent black.

[0057] Figure 3 The chromatogram of Solvent Black 5 spiked to the limit of quantitation in a nail polish blank matrix.

[0058] Figure 4 The chromatogram is a result of Solvent Yellow 44 and Disperse Orange 3 spiked to the limit of quantitation in a nail polish blank matrix.

[0059] Figure 5 The chromatogram of Solvent Black 5 spiked to the limit of quantitation in the eyeshadow blank matrix.

[0060] Figure 6 Chromatograms of Solvent Yellow 44 and Disperse Orange 3 spiked to the limit of quantitation in an eyeshadow blank matrix.

[0061] Figure 7 The chromatogram is of Solvent Black 5 spiked to the limit of quantitation in a shampoo blank matrix.

[0062] Figure 8 The chromatogram of Solvent Yellow 44 and Disperse Orange 3 spiked to the limit of quantitation in a shampoo blank matrix.

[0063] Figure 9 The chromatogram is of Solvent Black 5 spiked to the limit of quantitation in a blank base of hair dye.

[0064] Figure 10 The chromatograms of Solvent Yellow 44 and Disperse Orange 3 spiked to the limit of quantitation in a blank matrix of hair dye.

[0065] Figure 11 The chromatogram of Solvent Black 5 spiked to the limit of quantitation in a lipstick blank matrix.

[0066] Figure 12 The chromatogram of Solvent Yellow 44 and Disperse Orange 3 spiked to the limit of quantitation in a lipstick blank matrix.

[0067] Figure 13 Chromatogram of solvent black 5 in nail polish matrix detected by using an acetonitrile solution saturated with n-hexane as the extractant.

[0068] Figure 14 Chromatograms of three colorants were obtained for detecting unpurified, MCX-purified, and PA SPE-purified nail polish bases.

[0069] Figure 15 To determine the spiked recovery rates of three colorants in nail polish bases that were not purified, were MCX purified, and were PA SPE purified. Detailed Implementation

[0070] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0071] It should be noted that the process equipment or apparatus not specifically mentioned in the following embodiments are all conventional equipment or apparatus in the art.

[0072] Furthermore, it should be understood that the one or more method steps mentioned in this invention do not preclude the existence of other method steps before or after the combined steps, or the insertion of other method steps between these explicitly mentioned steps. Unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and is not intended to limit the order of the method steps or limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0073] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, this invention can be implemented using any prior art methods, apparatus, and materials similar to or equivalent to those described in the embodiments of this invention, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention.

[0074] The instrument and equipment information used in the embodiments of this invention is as follows:

[0075] 1260-Infinity III high-performance liquid chromatograph, Agilent Technologies; C18 column (5μm, 4.6 mm × 150 mm), Shimadzu Corporation; XS-205 electronic balance, Mettler AG, Switzerland.

[0076] Unless otherwise specified, all reagents used in this method are of chromatographic grade, and the water is Grade I water as specified in GB / T 6682.

[0077] Standards: Solvent Yellow 44 (CAS: 2478-20-8), purity ≥ 95%. Disperse Orange 3 (CAS: 730-40-5), purity ≥ 95%. Solvent Black 5 (CAS: 11099-03-9), moisture content ≤ 5%.

[0078] In the following specific embodiments, the sample to be tested is prepared using the following methods.

[0079] Sample preparation: Weigh the cosmetic sample to be tested into a centrifuge tube, add the extractant, vortex to mix, sonicate, and centrifuge; take the supernatant, dilute to volume with the extractant, and filter through a microporous membrane to obtain the sample solution to be tested; or directly use the extractant, vortex to mix, sonicate, and centrifuge; take the supernatant, dilute to volume with the extractant, and filter through a microporous membrane to obtain the blank solution.

[0080] Example 1: Detection of Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 in Nail Polish

[0081] (1) Sample preparation

[0082] Test sample: Weigh approximately 0.2 g (accurate to 1 mg) of the nail polish sample into a centrifuge tube, add 10 mL of methanol, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, dilute to 10 mL with methanol, filter through a 0.45 μm microporous membrane, and then test.

[0083] Blank solution: Add 10 mL of methanol to a centrifuge tube, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, dilute to 10 mL with methanol, filter through a 0.45 μm microporous membrane, and then test.

[0084] Blank matrix solution: Weigh approximately 0.2 g (accurate to 1 mg) of nail polish sample free of Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 into a centrifuge tube, add 10 mL of methanol, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, dilute to 10 mL with methanol, filter through a 0.45 μm microporous membrane, and then proceed with the analysis.

[0085] (2) Preparation of standard working solution

[0086] Solvent Yellow 44 stock solution (1000 mg / L): Accurately weigh 0.1 g (accurate to 0.0001 g) of Solvent Yellow 44 standard into a 100 mL volumetric flask, dissolve in methanol and dilute to the mark.

[0087] Disperse Orange 3 stock solution (1000 mg / L): Accurately weigh 0.1 g (accurate to 0.0001 g) of Disperse Orange 3 standard into a 100 mL volumetric flask, dissolve in methanol and dilute to the mark.

[0088] Solvent Black 5 stock solution (1000 mg / L): Accurately weigh 0.1 g (accurate to 0.0001 g) of Solvent Black 5 standard into a 100 mL volumetric flask, dissolve in methanol and dilute to the mark.

[0089] Mixed standard stock solutions: Take 5 mL of Solvent Yellow 44 stock solution, 5 mL of Dispersible Orange 3 stock solution, and 25 mL of Solvent Black 5 stock solution into a 100 mL volumetric flask, dilute to the mark with methanol, and shake well to obtain mixed standard stock solutions with concentrations of 50 mg / L, 50 mg / L, and 250 mg / L for Dispersible Orange 3, Solvent Yellow 44, and Solvent Black 5, respectively.

[0090] Standard working solutions: Pipette 0.2 mL, 0.5 mL, 1.0 mL, 2.0 mL, 5.0 mL, and 10.0 mL of the mixed standard stock solution into 50 mL volumetric flasks, dilute to the mark with methanol, and mix well to obtain the standard working solutions. The concentrations of Disperse Orange 3 and Solvent Yellow 44 are 0.2 μg / mL, 0.5 μg / mL, 1.0 μg / mL, 2.0 μg / mL, 5.0 μg / mL, and 10.0 μg / mL, respectively. The concentrations of Solvent Black 5 are 1 μg / mL, 2.5 μg / mL, 5.0 μg / mL, 10.0 μg / mL, 25.0 μg / mL, and 50.0 μg / mL, respectively.

[0091] (3) Liquid phase detection of the sample to be tested

[0092] ①The testing conditions are as follows:

[0093] Column: C18 (5 μm, 4.6 mm × 150 mm);

[0094] Column temperature: 30℃;

[0095] Injection volume: 10 μL;

[0096] Mobile phase: Phase A is a 20 mmol / L aqueous solution of ammonium acetate, and Phase B is methanol;

[0097] Flow rate: 1 mL / min;

[0098] Detection wavelengths: 435nm (solvent yellow 44, disperse orange 3), 567nm (solvent black 5);

[0099] Washing procedure:

[0100]

[0101] ②Plotting the standard curve

[0102] The standard working solutions were injected into the liquid chromatograph, and the peak area of ​​the corresponding substances was measured. A standard curve was plotted with the concentration of the substance in the standard working solutions as the abscissa (x) and the response value of the peak area as the ordinate (y). The linear equations and correlation coefficients of each component are shown in Table 1.

[0103] Table 1. Linear equations and correlation coefficients for Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5.

[0104]

[0105] Figure 1 The liquid chromatograms of the standards Solvent Yellow 44 and Disperse Orange 3.

[0106] Figure 2 The liquid chromatogram of solvent black as a standard

[0107] ③ Sample testing

[0108] The prepared test sample was injected into the liquid chromatograph for detection. No peak was observed at the corresponding retention time. The nail polish sample used in this embodiment does not contain Solvent Yellow 44, Disperse Orange 3, Solvent Black 5, or other prohibited colorants.

[0109] (4) Calculation of pigment content in nail polish

[0110] The peak area obtained from the test sample is determined using a multi-point calibration method. This embodiment employs a multi-point calibration method. The concentration of each substance in the test solution is calculated based on the standard curve using the multi-point calibration method.

[0111] The colorant content in cosmetics is expressed in milligrams per kilogram (mg / kg), calculated using formula (1).

[0112] (1)

[0113] X i —The content of the target substance in the sample, in milligrams per kilogram (mg / kg);

[0114] c i —The concentration of the colorant in the sample solution obtained from the standard curve, in micrograms per milliliter (μg / mL).

[0115] c i0 —The concentration of the colorant in the blank solution obtained from the standard curve, in micrograms per milliliter (μg / mL).

[0116] V — Sample detection volume, in milliliters (mL);

[0117] S — Dilution factor. When the concentration of colorant in the sample solution exceeds the detection range of the standard curve, the sample solution is diluted. When it is not diluted, S is 1.

[0118] m — the mass of the sample corresponding to the detection volume, in grams (g).

[0119] (5) Investigation of matrix effect

[0120] The slope of the standard curve prepared with methanol (Slope A) was compared with the slope of the standard curve prepared with the same concentration using a blank matrix (Slope B). The matrix effect (ME) was calculated using the formula (Slope B - Slope A) / Slope A × 100%, and the results were determined using the external standard method. The results are shown in Table 2.

[0121] (6) Limit of Quantitation of Detection Method

[0122] The standard solution was added to a nail polish blank matrix without the analyte, and the mixture was serially diluted and analyzed to find the lowest concentration level with a signal-to-noise ratio (S / N) ≥ 10. The S / N of the chromatograms for Disperse Orange 3 and Solvent Yellow 44 at a concentration level of 10 mg / kg, and Solvent Black 5 at a concentration level of 50 mg / kg, were all found to be between 11 and 125. Therefore, the limits of quantitation (LOQ) for Disperse Orange 3 and Solvent Yellow 44 meet the requirement of 10 mg / kg, and the LQ for Solvent Black 5 meets the requirement of 50 mg / kg. The chromatograms of the nail polish blank matrix spiked at the LQ are shown below. Figures 3-4 .

[0123] Figure 3 Chromatogram of Solvent Black 5 spiked to the limit of quantitation in a nail polish blank matrix.

[0124] Figure 4 Chromatogram of Solvent Yellow 44 and Disperse Orange 3 spiked to the limit of quantitation in a nail polish blank matrix.

[0125] (7) Method recovery and precision

[0126] Nail polish samples without the analyte were selected, and recovery tests were conducted by adding Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 at 1, 2, and 10 times the limit of quantitation levels. Each level was repeated 6 times.

[0127] The spiked recoveries and precision of Solvent Yellow 44 are shown in Table 3;

[0128] The spiked recoveries and precision of Disperse Orange 3 are shown in Table 4;

[0129] The spiked recovery and precision of Solvent Black 5 are shown in Table 5.

[0130] Example 2: Detection of Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 in Eyeshadow

[0131] (1) Preparation of the test sample

[0132] Weigh approximately 0.2 g (accurate to 1 mg) of the eyeshadow sample to be tested into a centrifuge tube, add 10 mL of methanol, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, make up to 10 mL with methanol, filter through a 0.45 μm microporous membrane, and then test.

[0133] Blank solution: Add 10 mL of methanol to a centrifuge tube, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, dilute to 10 mL with methanol, filter through a 0.45 μm microporous membrane, and then test.

[0134] Blank matrix solution: Weigh approximately 0.2 g (accurate to 1 mg) of eyeshadow sample (excluding Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5) into a centrifuge tube, add 10 mL of methanol, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, dilute to 10 mL with methanol, filter through a 0.45 μm microporous membrane, and then proceed with the analysis.

[0135] (2) Preparation of standard working solution

[0136] Same as Example 1

[0137] (3) Liquid phase detection of the sample to be tested

[0138] ① The detection conditions are the same as in Example 1.

[0139] ② The standard curve is plotted in the same way as in Example 1.

[0140] ③ Sample testing

[0141] The prepared test sample was injected into the liquid chromatograph for detection. No peak was observed at the corresponding retention time. The eyeshadow sample used in this embodiment does not contain the prohibited colorants Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5.

[0142] (4) Calculation of pigment content in eyeshadow

[0143] The peak area obtained from the test sample was used to determine the pigment content in the eyeshadow using a multi-point calibration method. The multi-point calibration method calculated the concentration of each substance in the test solution based on the standard curve.

[0144] The pigment content in the eyeshadow is expressed in milligrams per kilogram (mg / kg), and is calculated using formula (1) with multi-point correction. The calculation formula is the same as in Example 1.

[0145] (5) Investigation of matrix effect

[0146] The slope of the standard curve prepared with methanol (Slope A) was compared with the slope of the standard curve of the same concentration prepared with a blank matrix (a matrix containing eyeshadow without the analyte) (Slope B). The matrix effect (ME) was calculated using the formula (ME) = (Slope B - Slope A) / Slope A × 100%, and the results were determined using the external standard method. The results are shown in Table 2.

[0147] (6) Limit of Quantitation of Detection Method

[0148] The standard solution was added to the eyeshadow blank matrix without the analyte, and the mixture was serially diluted and analyzed to find the lowest concentration level with a signal-to-noise ratio (S / N) ≥ 10. The S / N of the chromatograms for Disperse Orange 3 and Solvent Yellow 44 at a concentration level of 10 mg / kg, and Solvent Black 5 at a concentration level of 50 mg / kg, were all found to be between 11 and 125. Therefore, the limits of quantitation (LOQ) for Disperse Orange 3 and Solvent Yellow 44 meet the requirement of 10 mg / kg, and the LQ for Solvent Black 5 meets the requirement of 50 mg / kg. The chromatogram of the eyeshadow blank matrix spiked at the LQ is shown below. Figures 5-6 .

[0149] Figure 5 Chromatogram of Solvent Black 5 spiked to the limit of quantitation in eyeshadow blank matrix.

[0150] Figure 6 Chromatogram of Solvent Yellow 44 and Disperse Orange 3 spiked to the limit of quantitation in an eyeshadow blank matrix.

[0151] (7) Method recovery and precision

[0152] Eyeshadow samples without the analyte were selected, and recovery tests were conducted by adding Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 at 1, 2, and 10 times the limit of quantitation levels. Each level was repeated 6 times.

[0153] The spiked recoveries and precision of Solvent Yellow 44 are shown in Table 3;

[0154] The spiked recoveries and precision of Disperse Orange 3 are shown in Table 4;

[0155] The spiked recovery and precision of Solvent Black 5 are shown in Table 5.

[0156] Example 3: Detection of Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 in Shampoo

[0157] (1) Preparation of the test sample

[0158] Weigh approximately 0.2 g (accurate to 1 mg) of the shampoo sample to be tested into a centrifuge tube, add 10 mL of methanol, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, dilute to 10 mL with methanol, filter through a 0.45 μm microporous membrane, and then test.

[0159] Blank solution: Add 10 mL of methanol to a centrifuge tube, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, dilute to 10 mL with methanol, filter through a 0.45 μm microporous membrane, and then test.

[0160] Blank matrix solution: Weigh approximately 0.2 g (accurate to 1 mg) of shampoo sample free of Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 into a centrifuge tube, add 10 mL of methanol, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, dilute to 10 mL with methanol, filter through a 0.45 μm microporous membrane, and then proceed with the analysis.

[0161] (2) Preparation of standard working solution

[0162] Same as Example 1.

[0163] (3) Liquid phase detection of the sample to be tested

[0164] ① The testing conditions are the same as in Example 1.

[0165] ②The standard curve is plotted in the same way as in Example 1.

[0166] ③ Sample testing

[0167] The prepared test sample was injected into the liquid chromatograph for detection. No peak was observed at the corresponding retention time. The shampoo sample used in this embodiment does not contain Solvent Yellow 44, Disperse Orange 3, Solvent Black 5, or other prohibited colorants.

[0168] (4) Calculation of pigment content in shampoo

[0169] The peak area obtained from the test sample was used to determine the pigment content in the shampoo using a multi-point calibration method. The concentration of each substance in the test solution was calculated based on the standard curve using the multi-point calibration method.

[0170] The pigment content in the shampoo is expressed in milligrams per kilogram (mg / kg) and is calculated using formula (1) with multi-point correction. The calculation formula is the same as in Example 1.

[0171] (5) Investigation of matrix effect

[0172] The slope of the standard curve prepared with methanol (Slope A) was compared with the slope of the standard curve of the same concentration prepared with a blank matrix (a matrix prepared with shampoo without the analyte) (Slope B). The matrix effect (ME) was calculated using the formula (ME) = (Slope B - Slope A) / Slope A × 100%, and the results were determined using the external standard method. The results are shown in Table 2.

[0173] (6) Limit of Quantitation of Detection Method

[0174] The standard solution was added to a blank shampoo matrix containing no analyte, and the solution was serially diluted and analyzed to find the lowest concentration level with a signal-to-noise ratio (S / N) ≥ 10. The S / N of the chromatograms for Disperse Orange 3 and Solvent Yellow 44 at a concentration level of 10 mg / kg, and Solvent Black 5 at a concentration level of 50 mg / kg, were all found to be between 11 and 125. Therefore, the limits of quantitation (LOQ) for Disperse Orange 3 and Solvent Yellow 44 meet the requirement of 10 mg / kg, and the LQ for Solvent Black 5 meets the requirement of 50 mg / kg. The chromatograms of the shampoo blank matrix spiked at the LQ are shown below. Figures 7-8 .

[0175] Figure 7 The chromatogram is of Solvent Black 5 spiked to the limit of quantitation in a shampoo blank matrix.

[0176] Figure 8 The chromatogram of Solvent Yellow 44 and Disperse Orange 3 spiked to the limit of quantitation in a shampoo blank matrix.

[0177] (7) Method recovery and precision

[0178] Shampoo samples without the analyte were selected, and recovery tests were conducted by adding Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 at 1, 2, and 10 times the limit of quantitation levels. Each level was repeated 6 times.

[0179] The spiked recoveries and precision of Solvent Yellow 44 are shown in Table 3;

[0180] The spiked recoveries and precision of Disperse Orange 3 are shown in Table 4;

[0181] The spiked recovery and precision of Solvent Black 5 are shown in Table 5.

[0182] Example 4: Detection of Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 in Hair Dye

[0183] (1) Preparation of the test sample

[0184] Weigh approximately 0.2 g (accurate to 1 mg) of the hair dye sample to be tested into a centrifuge tube, add 10 mL of methanol, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, dilute to 10 mL with methanol, filter through a 0.45 μm microporous membrane, and then test.

[0185] Blank solution: Add 10 mL of methanol to a centrifuge tube, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, dilute to 10 mL with methanol, filter through a 0.45 μm microporous membrane, and then test.

[0186] Blank matrix solution: Weigh approximately 0.2 g (accurate to 1 mg) of hair dye sample excluding Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 into a centrifuge tube, add 10 mL of methanol, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, dilute to 10 mL with methanol, filter through a 0.45 μm microporous membrane, and then test.

[0187] (2) Preparation of standard working solution

[0188] Same as Example 1.

[0189] (3) Liquid phase detection of the sample to be tested

[0190] ① The testing conditions are the same as in Example 1.

[0191] ②The standard curve is plotted in the same way as in Example 1.

[0192] ③ Sample testing

[0193] The prepared test sample was injected into the liquid chromatograph for detection. No peak was observed at the corresponding retention time. The hair dye sample used in this embodiment does not contain the prohibited colorants Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5.

[0194] (4) Calculation of pigment content in hair dye

[0195] The peak area obtained from the test sample was used to determine the pigment content in the hair dye using a multi-point calibration method. The concentration of each substance in the test solution was calculated based on the standard curve using the multi-point calibration method.

[0196] The pigment content in the hair dye is expressed in milligrams per kilogram (mg / kg), and is calculated using formula (2) with multi-point correction. The calculation formula is the same as in Example 1.

[0197] (5) Investigation of matrix effect

[0198] The slope of the standard curve prepared with methanol (Slope A) was compared with the slope of the standard curve of the same concentration prepared with a blank matrix (a matrix prepared with hair dye without the analyte) (Slope B). The matrix effect (ME) was calculated using the formula (ME) = (Slope B - Slope A) / Slope A × 100%, and the results were determined using the external standard method. The results are shown in Table 2.

[0199] (6) Limit of Quantitation of Detection Method

[0200] The standard solution was added to a blank hair dye matrix without the analyte, and the mixture was serially diluted and analyzed to find the lowest concentration level with a signal-to-noise ratio (S / N) ≥ 10. The S / N of the chromatograms for Disperse Orange 3 and Solvent Yellow 44 at a concentration level of 10 mg / kg, and Solvent Black 5 at a concentration level of 50 mg / kg, were all found to be between 11 and 125. Therefore, the limits of quantitation (LOQ) for Disperse Orange 3 and Solvent Yellow 44 meet the requirement of 10 mg / kg, and the LQ for Solvent Black 5 meets the requirement of 50 mg / kg. The chromatogram of the blank hair dye matrix spiked at the LQ is shown below. Figures 7-8 .

[0201] Figure 9 The chromatogram is of Solvent Black 5 spiked to the limit of quantitation in a blank base of hair dye.

[0202] Figure 10 The chromatograms of Solvent Yellow 44 and Disperse Orange 3 spiked to the limit of quantitation in a blank matrix of hair dye.

[0203] (7) Method recovery and precision

[0204] Hair dye samples without the analyte were selected, and recovery tests were conducted by adding Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 at 1, 2, and 10 times the limit of quantitation levels. Each level was repeated 6 times.

[0205] The spiked recoveries and precision of Solvent Yellow 44 are shown in Table 3;

[0206] The spiked recoveries and precision of Disperse Orange 3 are shown in Table 4;

[0207] The spiked recovery and precision of Solvent Black 5 are shown in Table 5.

[0208] Example 5: Detection of Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 in Lipstick

[0209] (1) Preparation of the test sample

[0210] Weigh approximately 0.2 g (accurate to 1 mg) of the lipstick sample to be tested into a centrifuge tube, add 2 mL of tetrahydrofuran, vortex to mix and disperse the sample (if the lipstick sample cannot be dispersed, it can be heated appropriately in an 80℃ water bath for 2 min), continue to add 8 mL of methanol to the centrifuge tube, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, make up to 10 mL with methanol, filter through a 0.45 μm microporous membrane, and then test.

[0211] Blank solution: Add 10 mL of methanol to a centrifuge tube, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, dilute to 10 mL with methanol, filter through a 0.45 μm microporous membrane, and then test.

[0212] Blank matrix solution: Weigh approximately 0.2 g (accurate to 1 mg) of lipstick sample free of Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 into a centrifuge tube, add 10 mL of methanol, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, dilute to 10 mL with methanol, filter through a 0.45 μm microporous membrane, and then proceed with the analysis.

[0213] (2) Preparation of standard working solution

[0214] Same as Example 1.

[0215] (3) Liquid phase detection of the sample to be tested

[0216] ① The testing conditions are the same as in Example 1.

[0217] ②The standard curve is plotted in the same way as in Example 1.

[0218] ③ Sample testing

[0219] The prepared test sample was injected into the liquid chromatograph for detection. No peak was observed at the corresponding retention time. The lipstick sample used in this embodiment does not contain Solvent Yellow 44, Disperse Orange 3, Solvent Black 5, or other prohibited colorants.

[0220] (4) Calculation of pigment content in lipstick

[0221] The peak area obtained from the test sample was used to determine the pigment content in the hair dye using a multi-point calibration method. The concentration of each substance in the test solution was calculated based on the standard curve using the multi-point calibration method.

[0222] The pigment content in the lipstick is expressed in milligrams per kilogram (mg / kg) and is calculated using formula (2) with multi-point correction. The calculation formula is the same as in Example 1.

[0223] (5) Investigation of matrix effect

[0224] The slope of the standard curve prepared with methanol (Slope A) was compared with the slope of the standard curve of the same concentration prepared with a blank matrix (a matrix prepared with lipstick without the analyte) (Slope B). The matrix effect (ME) was calculated using the formula (ME) = (Slope B - Slope A) / Slope A × 100%, and the results were determined using the external standard method. The results are shown in Table 2.

[0225] (6) Limit of Quantitation of Detection Method

[0226] The standard solution was added to a blank lipstick matrix without the analyte, and the mixture was serially diluted and analyzed to find the lowest concentration level with a signal-to-noise ratio (S / N) ≥ 10. The S / N of the chromatograms for Disperse Orange 3 and Solvent Yellow 44 at a concentration level of 10 mg / kg, and Solvent Black 5 at a concentration level of 50 mg / kg, were all found to be between 11 and 125. Therefore, the limits of quantitation (LOQ) for Disperse Orange 3 and Solvent Yellow 44 meet the requirement of 10 mg / kg, and the LQ for Solvent Black 5 meets the requirement of 50 mg / kg. The chromatograms of the lipstick blank matrix spiked at the LQ are shown below. Figures 7-8 .

[0227] Figure 11 The chromatogram of Solvent Black 5 spiked to the limit of quantitation in a lipstick blank matrix.

[0228] Figure 12 The chromatogram of Solvent Yellow 44 and Disperse Orange 3 spiked to the limit of quantitation in a lipstick blank matrix.

[0229] (7) Method recovery and precision

[0230] Lipstick samples without the analyte were selected, and recovery tests were conducted by adding Solvent Yellow 44, Disperse Orange 3, and Solvent Black 5 at 1, 2, and 10 times the limit of quantitation levels. Each level was repeated 6 times.

[0231] The spiked recoveries and precision of Solvent Yellow 44 are shown in Table 3;

[0232] The spiked recoveries and precision of Disperse Orange 3 are shown in Table 4;

[0233] The spiked recovery and precision of Solvent Black 5 are shown in Table 5.

[0234] Table 2. Matrix effect of different cosmetic samples

[0235]

[0236] According to the criteria for determining matrix effects, a matrix effect is defined as follows: |ME| < 20% indicates a weak matrix effect; 20% < |ME| < 50% indicates a moderate matrix effect; and |ME| > 50% indicates a strong matrix effect. Table 2 shows that all matrix effects were classified as weak matrix effects when using the external standard method for quantification.

[0237] Table 3. Spike recovery and precision of Solvent Yellow 44

[0238]

[0239] Table 4. Spike recovery and precision of Disperse Orange 3

[0240]

[0241] Table 5. Spiking recovery and precision of Solvent Black 5

[0242]

[0243] The spiked recovery test results in Tables 3-5 show that the spiked recoveries of the three pigments in various matrices are between 80% and 110%, and the precision is between 0.11% and 5.2%, which meets the requirements of SN / T 0001-2016 for recovery rate and precision.

[0244] Example 6 Stability testing of standard solutions

[0245] Following the method for stability testing of standard solutions in SN / T 0001-2016, the stability of stock solutions of three colorants (Solvator Yellow 44, Disperse Orange 3 at 10.0 mg / L, and Solvator Black 5 at 50 mg / L) was investigated. A total of 25 stock solutions were prepared and stored at -20℃ in the dark, 4℃ in the dark, 4℃ under light, 20℃ in the dark, and 20℃ under light, respectively. Starting from July 19, 2025, tests were conducted every week (1 week), with the testing interval gradually increasing. Each time a test was conducted, the standard solution was diluted and compared with a freshly prepared standard solution using the following formula. The content of the remaining analyte is shown in Table 6.

[0246] Remaining analyte (%) = C i ×100 / C 新配

[0247] C i Indicates the concentration of the standard solution at the corresponding time point; C 新配 This indicates the concentration of the newly prepared standard solution.

[0248] Table 6. Results of the stability study of the standard solutions

[0249]

[0250] As shown in Table 6, the standard solution stored at -20℃ and protected from light is the most stable, and no significant degradation was found within 1 month. Therefore, -20℃ protected from light and 1 month are taken as the storage conditions and shelf life of the standard stock solution.

[0251] Comparative Example 1

[0252] This comparative example is a comparative example of Example 1, except that the extractant used is an acetonitrile solution saturated with n-hexane.

[0253] (1) Sample preparation

[0254] Weigh approximately 0.2 g (accurate to 1 mg) of the nail polish sample to be tested into a centrifuge tube, add 10 mL of hexane-saturated acetonitrile solution, vortex to mix, sonicate for 20 min, and then centrifuge at 6000 r / min for 10 min. Take the clear extract, dilute to 10 mL with hexane-saturated acetonitrile solution, filter through a 0.45 μm microporous membrane, and then test.

[0255] (2) Liquid phase detection of the sample to be tested

[0256] ① Detection conditions are the same as in Example 1.

[0257] ② When the sample was tested, and hexane-saturated acetonitrile was used as the extraction solvent, a shoulder peak appeared at the elution position of solvent black 5, making separation difficult and resulting in an uneven baseline. The liquid chromatography spectrum is shown below. Figure 13 As shown.

[0258] Figure 13 Chromatogram of solvent black 5 in nail polish matrix detected by using an acetonitrile solution saturated with n-hexane as the extractant.

[0259] Comparative Example 2

[0260] Comparative Example 2 is a comparative example of Example 1, except that it uses an MCX (60 mg / 3 mL) cation exchange column to purify the sample solution.

[0261] (1) Preparation of spiked sample: Add colorant standard to nail polish without prohibited colorant, add 2 mL tetrahydrofuran and 1 mL dimethyl sulfoxide to spiked sample, vortex mix, add 5 mL methanol, extract by ultrasonication for 10 min, centrifuge at 4500 r / min for 10 min to obtain supernatant.

[0262] (2) A Waters oasis MCX (60 mg / 3 mL) cation exchange column was used (activated sequentially with 3 mL of methanol and 3 mL of water before use). The supernatant of the spiked sample was passed through the oasis MCX cation exchange column and rinsed sequentially with 3 mL of water and 20% methanol aqueous solution. The rinsing solution was discarded, and the sample was eluted with 10 mL of 1% ammonia-methanol solution. The eluent was collected and purged with nitrogen at 45 °C until nearly dry. The volume was adjusted to 1 mL with the mobile phase, vortexed, filtered through a filter membrane, and then analyzed.

[0263] (3) The liquid chromatography detection method for the sample to be tested is the same as in Example 1.

[0264] The chromatograms of unpurified and purified samples are shown below. Figure 14 As shown in the bar chart, the recovery rate is calculated as follows: Figure 15 As shown in SPE1.

[0265] Depend on Figure 14It can be seen that, in terms of interference with the peak positions of the colorants, after the sample was purified by the MCX (60mg / 3mL) cation exchange column, there was no significant interference with the peak positions of the three colorants.

[0266] Depend on Figure 15 It can be seen that the recovery rates of the three colorants can all reach a high level without purification. After purification by MCX (60mg / 3mL) cation exchange column (SPE1), the recovery rates of the three colorants all decreased to varying degrees. Among them, Disperse Orange 3 and Solvent Black 5 decreased by about 10%, and Solvent Yellow 44 decreased significantly. The recovery rate after purification was less than 20%, which is difficult to meet the requirements.

[0267] Comparative Example 3

[0268] Comparative Example 3 is a comparative example of Example 1, except that it uses a PA SPE (500 mg / 3 mL) polyamide solid phase extraction column to purify the sample solution.

[0269] (1) Preparation of spiked sample: Add colorant standard to nail polish without prohibited colorant, add 2 mL tetrahydrofuran and 1 mL dimethyl sulfoxide to spiked sample, vortex mix, add 5 mL methanol, extract by ultrasonication for 10 min, centrifuge at 4500 r / min for 10 min to obtain supernatant.

[0270] (2) Anpelclean PA SPE (500 mg / 3 mL) polyamide solid-phase extraction column was selected (activated with 3 mL methanol and 3 mL water before use). The supernatant of the spiked sample was passed through the PA SPE polyamide solid-phase extraction column, rinsed with 3 mL water, discarded, and eluted with 10 mL of 10% ammonia-methanol solution. The eluent was collected and purged with nitrogen at 45 °C until nearly dry. The volume was adjusted to 1 mL with the mobile phase, vortexed, filtered through a filter membrane, and then analyzed.

[0271] (3) The liquid chromatography detection method for the sample to be tested is the same as in Example 1.

[0272] The chromatograms of unpurified and purified samples are shown below. Figure 14 As shown in the bar chart, the recovery rate is calculated as follows: Figure 15 As shown in SPE2.

[0273] Depend on Figure 14 It can be seen that, in terms of interference with the peak positions of the colorants, after the sample was purified by PA SPE (500mg / 3mL) polyamide solid phase extraction column, there was no obvious interference with the peak positions of the three colorants.

[0274] Depend on Figure 15It can be seen that the recovery rates of the three colorants can reach a high level without purification. However, after purification using a PA SPE (500mg / 3mL) polyamide solid-phase extraction column (SPE2), the recovery rates of the three colorants decreased significantly, and the recovery rates of the three colorants after purification were all less than 20%, which is difficult to meet the detection requirements.

[0275] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any form or substance. It should be noted that those skilled in the art can make various improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of the present invention are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for simultaneous detection of multiple prohibited colorants in cosmetics, characterized in that, The method includes: 1) Sample preparation, including: dissolving the cosmetic to be tested in the extractant, centrifuging to obtain the supernatant, filtering through a microporous membrane to obtain the sample to be tested; using the extractant as a blank control solution; 2) Sample testing, including: using a liquid chromatograph to test the sample, and using a standard curve method to quantitatively analyze the colorant in the sample; 3) Calculation of the content of prohibited colorants in cosmetics.

2. The detection method according to claim 1, characterized in that, The colorant is one or more of Solvent Yellow 44, Disperse Orange 3, or Solvent Black 5; And / or, the cosmetic is selected from one or more of nail polish, eyeshadow, shampoo, hair dye or lipstick; And / or, the extractant is selected from one or more of methanol, acetonitrile, or tetrahydrofuran.

3. The detection method according to claim 1, characterized in that, In step 1), based on 0.1g of the cosmetic sample to be tested, the amount of extractant added is 1~5mL; And / or, in step 1), the volume of the final volume is 5 to 10 mL, based on 0.1 g of the cosmetic sample to be tested.

4. The detection method according to claim 1, characterized in that, The extraction process is accompanied by ultrasonic treatment at a temperature of 20-60°C. And / or, the pore size of the microporous filter membrane is 0.20~0.50μm.

5. The detection method according to claim 1, characterized in that, In step 2), the chromatographic detection conditions include: 1) The chromatographic column is a C18 column; 2) Column temperature is 30~40℃; 3) The injection volume is 10~20μL; 4) The flow rate is 0.7~1.2 mL / min; 5) The mobile phase is phase A: 15~20 mmol / L ammonium acetate aqueous solution, and phase B: methanol; 6) Detection wavelengths: 435nm, 567nm; 7) Elution method: gradient elution.

6. The detection method according to claim 5, characterized in that, The gradient elution includes: initial solvent composition: 65%~70% phase A and 30%~35% phase B; 65%~70% phase A is maintained for 0~4 min; the proportion of phase A decreases linearly to 15%~20% for 4~5 min; 15%~20% phase A is maintained for 5~9 min; the proportion of phase A decreases linearly to 5%~8% for 9~10 min; 5%~8% phase A is maintained for 10~16 min; the proportion of phase A increases linearly to 65%~70% for 16 min~16.1 min; and 65%~70% phase A is maintained for 16.1 min~21 min.

7. The detection method according to claim 5, characterized in that, The C18 column has a packing particle size of 5μm and a column size of 4.6 mm × 150 mm. And / or, the detection employs a diode array detector, performing dual-wavelength synchronous detection at wavelengths of 435nm and 567nm.

8. The detection method according to claim 1, characterized in that, The concentrations of the colorant standard solutions selected in the establishment of the standard curve range from 0.2 to 100 μg / mL.

9. The detection method according to claim 1, characterized in that, In step 3), the content of colorant in the cosmetic sample is calculated according to the following formula; The content of colorant in the sample (mg / kg) = ; In the formula, C i The concentration of the colorant in the sample solution, calculated from the standard curve, is expressed in μg / mL. C i0 The concentration of the colorant in the blank solution, calculated from the standard curve, is expressed in μg / mL. V represents the detection volume, in mL; S is the dilution factor. When the concentration of colorant in the sample solution exceeds the detection range of the standard curve, the sample solution is diluted. When it is not diluted, S is 1. m represents the mass of the sample corresponding to the detection volume, in grams.

10. The use of the detection method as described in any one of claims 1 to 9 to detect prohibited colorants in cosmetics.

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