CN114200036B

CN114200036B - Method for detecting additive in cosmetics or raw materials thereof

Info

Publication number: CN114200036B
Application number: CN202111323469.5A
Authority: CN
Inventors: 周智明; 周桓; 肖树雄; 李静; 陆土柳
Original assignee: Guangdong Institute For Drug Control (guangdong Institute For Drug Quality
Current assignee: Guangdong Institute For Drug Control (guangdong Institute For Drug Quality
Priority date: 2021-11-09
Filing date: 2021-11-09
Publication date: 2023-11-28
Anticipated expiration: 2041-11-09
Also published as: CN114200036A

Abstract

A detection method of cosmetics or additives in raw materials thereof comprises the following steps: and detecting the liquid to be detected by adopting a high performance liquid chromatography, wherein the additive comprises at least one of retinoic acid, isotretinoin, hydroxy pinacolone retinoate, retinaldehyde, retinol acetate, retinol palmitate, retinol propionate and retinol retinoic acid ester. The detection method of the invention firstly establishes a high performance liquid chromatography detection method of 9 retinol substances such as retinoic acid, isotretinoin, retinol, retinaldehyde, retinol acetate, hydroxy pinacolone retinol, retinol propionate, retinol palmitate and the like in cosmetics or raw materials thereof, and the detection range covers 7 retinol substances and two degradation products thereof in cosmetics and raw material catalogues thereof, and the detection method is accurate and has high stability.

Description

Method for detecting additive in cosmetics or raw materials thereof

Technical Field

The invention belongs to the technical field of detection, and particularly relates to a detection method of an additive in cosmetics or raw materials thereof.

Background

Along with the development of cosmetic formulations and the continuous progress of processes, various functional cosmetics and raw materials are commonly applied, and compatibility degradation products, introduction of residual substances and the like in the products are factors influencing the safety of the products. Retinol substances are new acne-removing and anti-wrinkle raw materials in recent years, and comprise retinol, retinoic acid, retinaldehyde, retinyl ester and the like, and the retinol substances can improve abnormal keratinization and sebum excretion of epithelial cells and are clinically used as acne-removing and anti-wrinkle medicines. Although retinol is an essential active substance for the human body and is converted into retinoic acid in the body, excessive intake has the disadvantages of hepatomegaly, calcium loss, teratogenesis, etc. Retinoic acid and isotretinoin are highly irritating, have teratogenicity and embryotoxicity, and can only be used as prescription drugs, and are forbidden components in cosmetics. Studies have shown that these derivatives only act to improve aging after in vivo conversion to retinoic acid, and that interaction of retinol with other cosmetic base materials under foreseeable use conditions can result in conversion to retinoic acid or other unknown compounds, and risk assessment of such materials will focus on the effect of the conversion products on toxicity results.

Retinol, retinaldehyde and retinyl esters are common ingredients for removing wrinkles and resisting aging in cosmetics, and 8 retinol substances are recorded in the catalogue of the names of used cosmetic raw materials. The detection method of the vitamin A derivatives reported in the literature mainly aims at food, and the detection method in cosmetics only comprises the detection method of very specific derivatives such as retinoic acid, retinol and the like.

Disclosure of Invention

In order to overcome the problems of the prior art, the invention aims to provide a detection method of additives in cosmetics or raw materials thereof.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a detection method of cosmetics or additives in raw materials thereof comprises the following steps: and detecting the to-be-detected liquid of the cosmetics or the cosmetic raw materials by adopting a high performance liquid chromatography, wherein the additive comprises at least one of retinoic acid, isotretinoin, hydroxy pinacolone retinoic acid ester, retinaldehyde, retinol acetate, retinol palmitate, retinol propionate and retinol ester.

Preferably, the additive comprises retinoic acid, isotretinoin, hydroxy pinacolone retinoate, retinaldehyde, retinol acetate, retinol palmitate, retinol propionate, retinol retinoate.

Preferably, the chromatographic conditions are: the chromatographic column is as follows: a C18 chromatographic column; the sample injection amount is as follows: 4-6 mu L; the flow rate is: 0.8-1.2 mL/min; the mobile phase is: mobile phase a is acetonitrile; mobile phase B is tetrahydrofuran; the mobile phase C is ammonium acetate solution, and elution is carried out by adopting a gradient elution mode.

Preferably, the sample injection amount is: 4.5 to 5.5 mu L; further preferably, the sample injection amount is: 5. Mu.L.

Preferably, the flow rate is: 1 to 1.2mL/min; further preferably, the flow rate is: 1mL/min;

preferably, the gradient elution procedure is:

0min, 35% by volume of mobile phase A, 35% by volume of mobile phase B and 30% by volume of mobile phase C;

4-20 min, wherein the volume percentage of the mobile phase A is 38%, the volume percentage of the mobile phase B is 38%, and the volume percentage of the mobile phase C is 24%;

21-41 min, the volume percentage of the mobile phase A is 45%, the volume percentage of the mobile phase B is 45%, and the volume percentage of the mobile phase C is 10%;

41.01-46 min, the volume percentage of the mobile phase A is 35%, the volume percentage of the mobile phase B is 35%, and the volume percentage of the mobile phase C is 30%.

Preferably, the concentration of the mobile phase C is 4-6 mmol/L; further preferably, the concentration of mobile phase C is 5mmol/L.

Preferably, the pH value of the mobile phase is 6-7; further preferably, the pH of the mobile phase is 6.5 to 7; still further preferably, the mobile phase has a pH of 6.5.

Preferably, the diameter of the C18 chromatographic column is 4-5 mm, the length is 200-300 mm, and the particle size of the packing is 4-6 mu m.

Preferably, the C18 chromatographic column is: titank C18 (250X 4.6mm,5 μm) or ZORBAX Eclispse Plus C (250X 4.6mm,5 μm).

Preferably, the column temperature of the C18 chromatographic column is: 24-36 ℃; further preferably, the column temperature of the C18 chromatographic column is: 25-30 ℃; still further preferably, the column temperature of the C18 chromatographic column is: 30 ℃.

Preferably, the liquid to be measured of the cosmetic or cosmetic raw material includes a sample solution; the sample solution is obtained by mixing and extracting a sample of cosmetics or cosmetic raw materials with an extraction solvent; the extraction solvent is at least one of methanol, acetonitrile, isopropanol and tetrahydrofuran.

Preferably, the mixing extraction is by vortex mixing and ultrasonic extraction.

Preferably, the vortex mixing time is 24-36 s; further preferably, the vortex mixing time is 25 to 30 seconds.

Preferably, the ultrasonic extraction time is 12-18 min; further preferably, the ultrasonic extraction time is 15 to 18 minutes.

Preferably, the sample solution is filtered prior to detection.

Preferably, the filtration is carried out by adopting a filter membrane with the diameter of 0.30-0.65 mu m; further preferably, the filtration is carried out with a 0.45 μm filter.

Preferably, the extracting solvent is a mixed solution of acetonitrile and tetrahydrofuran, and the volume ratio of acetonitrile to tetrahydrofuran in the mixed solution is (3-5) 1; further preferably, the extraction solvent is a mixed solution of acetonitrile and tetrahydrofuran, and the volume ratio of acetonitrile to tetrahydrofuran in the mixed solution is (3.5-4.5): 1; still further preferably, the extraction solvent is a mixed solution of acetonitrile and tetrahydrofuran, and the volume ratio of acetonitrile to tetrahydrofuran in the mixed solution is 4:1.

Preferably, the detector of the chromatograph is a PDA detector, and the detection wavelength is: 325nm.

Preferably, the liquid to be measured further comprises a standard working liquid.

Preferably, the standard working solution is prepared by the following method: preparing a standard stock solution with the mass concentration of 1000mg/L from a standard product by using methanol, and then diluting the standard stock solution into more than 3 standard working solutions with different mass concentrations; further preferably, the standard working fluid is prepared by the following method: preparing a standard stock solution with the mass concentration of 1000mg/L from a standard product by using methanol, and then diluting the standard stock solution into more than 5 standard working solutions with different mass concentrations; still further preferably, the standard working fluid is formulated by the following method: the standard substance is prepared into a standard stock solution with the mass concentration of 1000mg/L by using methanol, and then diluted into 6 standard working solutions with different mass concentrations of 0.5mg/L, 5mg/L, 10mg/L, 20mg/L, 50mg/L and 100 mg/L. The standard substance is retinoic acid, isotretinoin, hydroxy pinacolone retinoate, retinaldehyde, retinol acetate, retinol palmitate, retinol propionate, retinol retinoate.

The beneficial effects of the invention are as follows: the detection method of the invention firstly establishes a high performance liquid chromatography detection method of 9 retinol substances such as retinoic acid, isotretinoin, retinol, retinaldehyde, retinol acetate, hydroxy pinacolone retinoate, retinol propionate, retinol palmitate and the like in cosmetics or raw materials thereof, and the detection range covers 7 retinol substances (retinol, retinaldehyde, retinol acetate, hydroxy pinacol retinol, retinol propionate, retinol palmitate and two degradation products (retinoic acid and isotretinoin) in the raw material catalogue, and the detection method is accurate and has high stability.

The detection method has good linearity in the range of 0.5-100mg/L when detecting 9 retinol related components, the correlation coefficient is more than 0.99, and the detection concentration is 0.4mg/kg (S/N=3). The recovery rate of the blank matrix is 85.3-116.1%, and the relative standard deviation is 0.7-9.8%, so that technical support can be provided for monitoring the degradation condition of retinol raw materials, the stability research and risk evaluation of the raw materials.

Drawings

FIG. 1 is a liquid chromatogram of a mixed standard working solution of 9 retinoids;

FIG. 2 is a liquid chromatogram of 9 retinoids in an isopropanol system;

FIG. 3 is a liquid chromatogram of 9 retinoids in tetrahydrofuran system;

FIG. 4 is a liquid chromatogram of 9 retinoids at different pH conditions;

FIG. 5 is a liquid chromatogram of 9 retinoids at different column temperatures;

fig. 6 is a liquid chromatogram of a labeled sample of 9 retinoids.

Detailed Description

Specific embodiments of the present invention will be described in further detail below with reference to the drawings and examples, but the practice and protection of the present invention are not limited thereto. It should be noted that the following processes, unless otherwise specified, are all realized or understood by those skilled in the art with reference to the prior art. The reagents or apparatus used were not manufacturer-specific and were considered conventional products commercially available.

Example 1

Instrument and reagent

The adopted instrument is as follows: an Agilent 1260 affinity high performance liquid chromatograph equipped with a G1329B autosampler, a G1316A column oven, a G1315C diode array detector; elma S300H ultrasonic cleaner; ikaLabDancer vortex mixer; millipore Milli Q Reference type ultrapure water generator, METTER MSDU electronic balance (1/100000).

The adopted reagents are as follows: retinoic acid (99.90%, national institute of pharmaceutical and biological products); iso-retinoic acid (99.80%, national institute of pharmaceutical and biological products); hydroxy pinacolone retinoate (99.00%, microphone); retinaldehyde (98.17%, aladin); retinol acetate (98.80%, bePure); retinol palmitate (97.60%, bePure); retinol (99.30%, altar ink quality inspection); retinol propionate (90.00%, TRC); retinol retinoic acid ester (98.46%, microphone); ammonium acetate (analytically pure); acetonitrile, tetrahydrofuran (both chromatographically pure); the experimental water is first-grade purified water.

The method for testing the additive in the cosmetics or the raw materials thereof in the example comprises the following steps:

(1) Preparing standard working solution

The standard substances of 9 retinol substances (retinoic acid, isotretinoin, hydroxy pinacolato retinoic acid ester, retinaldehyde, retinol acetate, retinol palmitate, retinol propionate and retinol retinoic acid ester) are respectively weighed 10mg (accurate to 0.1 mg) in a 10mL volumetric flask, dissolved by methanol and fixed in volume (wherein, a proper amount of isopropanol is required to be added to dissolve the standard substances, and then methanol is added to fix the volume) to prepare a standard stock solution with the mass volume of 1000 mg/L. And (3) diluting a proper amount of standard stock solution with methanol to obtain 5 standard working solutions with mass concentrations of 5mg/L, 10mg/L, 20mg/L, 50mg/L and 100mg/L, and storing in a dark place at 4 ℃.

(2) Sample pretreatment

1g of a pasty sample (accurate to 0.001 g) was taken in a 10ml cuvette with plug, acetonitrile was added: tetrahydrofuran (volume ratio 80:20) to scale, vortexing for 30s, fully mixing the sample with the extraction solvent, ultrasonically extracting for 15min, standing to room temperature, and filtering with 0.45 μm filter membrane to obtain filtrate as the solution to be detected. The pretreatment steps of the emulsion sample and the frost sample are the same as those of the paste sample. The aqueous sample can be directly extracted with methanol.

(3) Testing using high performance liquid chromatograph

The chromatographic test conditions are as follows: chromatographic column: c18 250mm 4.6mm 5 μm; column temperature: 30 ℃; sample injection amount: 5. Mu.L; flow rate: 1.0ml/min; detection wavelength: 325nm; mobile phase a: acetonitrile; mobile phase B: tetrahydrofuran; mobile phase C:5mmol/L ammonium acetate solution, the elution mode is gradient elution, and the specific elution program is shown in Table 1:

TABLE 1 gradient elution procedure

Time (min)	Mobile phase a (%)	Mobile phase B (%)	Mobile phase C (%)
				0	35	35	30
4	38	38	24
				20	38	38	24
21	45	45	10
				41	45	45	10
41.01	35	35	30
				46	35	35	30

The elution is carried out according to the gradient elution program to obtain a liquid chromatogram of the mixed standard working solution of 9 retinol substances, specifically shown in fig. 1, and can be seen from fig. 1: chromatographic peak a1 is retinoic acid (5.240 min); chromatographic peak a2 is isotretinoin (5.981 min); chromatographic peak a7 is retinol (8.145 min); chromatographic peak a5 is retinol acetate (14.425 min); chromatographic peak a4 is retinaldehyde (15.105 min); chromatographic peak a3 is hydroxy pinacolone retinoate (16.209 min); chromatographic peak a8 is retinol propionate (17.659 min); chromatographic peak a9 is retinol retinoic acid ester (32.545 min); the chromatographic peak a6 is retinol palmitate (35.452 min).

And (3) optimizing detection conditions:

1. selection of chromatographic conditions

Selection of chromatographic columns:

the C18 column is suitable for non-polar, weak polar and medium polar compound analysis, and for analysis of lower molecular weight compounds. Therefore, the invention selects the conventional C18 chromatographic column for separation, and respectively inspects the C18 chromatographic column of two brands of Titank C18 (250 multiplied by 4.6mm,5 mu m, phenanthrene) and ZORBAX Eclispse Plus C (250 multiplied by 4.6mm,5 mu m, agilent), and the result shows that under the same chromatographic condition, 9 retinol substances can obtain good separation effect and chromatographic peak shape on the two C18 chromatographic columns, and can meet the requirement of system adaptability, and ZORBAX Eclispse Plus C18 is selected as the analysis chromatographic column in the embodiment of the invention.

Selection of mobile phase:

in the reversed-phase high-efficiency chromatography, water is used as a mobile phase main body, and methanol, acetonitrile, tetrahydrofuran and isopropanol are used as modifiers. The acetonitrile has strong eluting capability and low viscosity, the back pressure of the column is lower than that of methanol under the same condition, and the absorption and interference of the acetonitrile are lower than those of the methanol at a short wavelength. Thus, the present invention employs acetonitrile as one of the components of the ternary mobile phase.

The invention respectively examines the influences of the total 7 mobile phase systems on the chromatographic behaviors of 9 retinol substances, namely, acetonitrile-isopropanol-water, acetonitrile-tetrahydrofuran-water, acetonitrile-isopropanol-ammonium acetate, acetonitrile-tetrahydrofuran-ammonium formate, acetonitrile-tetrahydrofuran-potassium dihydrogen phosphate and acetonitrile-tetrahydrofuran-sodium dihydrogen phosphate, wherein the specific results are shown in fig. 2 and 3, and fig. 2 is a liquid chromatogram of 9 retinol substances in an isopropanol system, and fig. 2 (a) is a liquid chromatogram of 9 retinol substances in the acetonitrile-isopropanol-water system; FIG. 2 (b) is a liquid chromatogram of 9 retinoids in an acetonitrile-isopropanol-ammonium acetate system. As can be seen from fig. 2 (a) and 2 (b): in the isopropanol system, retinaldehyde and retinyl acetate, hydroxy pinacolone retinoate, were not effectively separated and the chromatographic peak was poor. FIG. 3 is a liquid chromatogram of 9 retinoids in tetrahydrofuran system; wherein, figure 3 (a) is a liquid chromatogram of 9 retinol substances in an acetonitrile-tetrahydrofuran-water system; FIG. 3 (b) is a liquid chromatogram of 9 retinoids in acetonitrile-tetrahydrofuran-ammonium acetate system; FIG. 3 (c) is a liquid chromatogram of 9 retinoids in acetonitrile-tetrahydrofuran-sodium dihydrogen phosphate system; FIG. 3 (d) is a liquid chromatogram of 9 retinoids in acetonitrile-tetrahydrofuran-potassium dihydrogen phosphate system; FIG. 3 (e) is a liquid chromatogram of 9 retinoids in acetonitrile-tetrahydrofuran-ammonium formate system. As can be seen from FIG. 3, in the tetrahydrofuran system, when potassium dihydrogen phosphate or sodium dihydrogen phosphate is used as a buffer solution, retinoic acid and isotretinoin are not effectively separated. When the ammonium acetate is a buffer solution, the separation effect and peak shape of each component are better than those of ammonium formate and water. Finally acetonitrile-tetrahydrofuran-ammonium acetate is selected as a mobile phase system, and elution is carried out by adopting a gradient elution program.

Selection of buffer pH:

in the reversed-phase high-performance liquid chromatography, the pH value of the mobile phase is adjusted, so that the dissociation of the compound can be inhibited, the tailing is reduced, the peak shape is improved, and the separation selectivity is improved. The invention examines the influence of buffer solution pH values of 4.5, 5.5, 6.5, 7.5 and 8.5 on the chromatographic behavior of each component, and the specific result is shown in figure 4, wherein: FIG. 4 (a) is a liquid chromatogram of 9 retinoids at pH 4.5; FIG. 4 (b) is a liquid chromatogram of 9 retinoids at pH 5.5; FIG. 4 (c) is a liquid chromatogram of 9 retinoids at pH 6.5; FIG. 4 (d) is a liquid chromatogram of 9 retinoids at pH 7.5; FIG. 4 (e) is a liquid chromatogram of 9 retinoids at pH 8.5. As can be seen from fig. 4, at pH 4.5, three substances, retinoic acid, isotretinoin and retinol, were not effectively separated. And under other pH values, no obvious difference exists among the 9 retinol substances. The pH of the buffer solution is finally selected to be 6.5 by comprehensively considering the applicable conditions of the chromatographic column, the performance of retinol substances and the pka value of the buffer salt.

Column temperature selection:

in general, during chromatography, column temperature can affect the binding and separation of compounds in the mobile phase from the stationary phase. The activity of the column packing is enhanced with the increase of the column temperature within the allowable range of the column, the elution capacity of the compound is enhanced, and the retention time of the compound is shortened. Therefore, the invention respectively examines the influence of different column temperatures (25 ℃, 30 ℃, 35 ℃ and 40 ℃) on the chromatographic behavior of 9 retinol substances, and the specific results are shown in a figure 5, wherein, the figure 5 (a) is a liquid chromatogram of 9 retinol substances under the condition that the column temperature is 25 ℃; FIG. 5 (b) is a liquid chromatogram of 9 retinoids at a column temperature of 30deg.C; FIG. 5 (c) is a liquid chromatogram of 9 retinoids at a column temperature of 35 ℃; FIG. 5 (d) is a liquid chromatogram of 9 retinoids at a column temperature of 40 ℃. As can be seen in FIG. 5, the relative retention times of retinoic acid and isotretinoin at 25, 35, and 40℃are both advanced over 30 ℃; the relative retention times of the remaining 7 components all advanced with increasing column temperature, so the present invention finally selects a column temperature of 30 ℃.

2. Selection of sample extraction solutions

The invention selects cream and water samples, and respectively examines methanol, acetonitrile and methanol: tetrahydrofuran (80:20), acetonitrile: four extraction solvents of tetrahydrofuran (80:20). The test results show that: the extract effect of the cream sample in methanol or acetonitrile is poor; in acetonitrile: the tetrahydrofuran (80:20) has good dispersing effect and good extraction effect. The aqueous sample has good extraction effect on all the four extraction solvents.

3. Linear equation, method detection limit and quantitative limit

Taking standard working solutions of 9 retinol substances (retinoic acid, isotretinoin, hydroxy pinacolato retinoic acid ester, retinaldehyde, retinol acetate, retinol palmitate, retinol propionate and retinol retinoic acid ester) with different concentration gradients, wherein the specific concentration gradients are as follows: 0.5mg/L, 5mg/L, 10mg/L, 20mg/L, 50mg/L, 100mg/L, tested according to the test conditions in the examples of the present invention, the mass concentration thereof was linearly regressed with the peak area, the detection Limit (LOD) was calculated with a 3-fold signal-to-noise ratio (S/N), and the quantitative Limit (LOQ) was calculated with a 10-fold signal-to-noise ratio (S/N). The detection limit of the method for 9 retinol substances is 0.4mg/kg, the quantitative limit of the method is 1mg/kg, and the correlation coefficient is more than 0.99 within the linear range of 0.5 mg/L-100 mg/L, which indicates that the 9 retinol substances have good linear relation. The linear regression equation, correlation coefficient and method detection concentration of 9 retinol substances are shown in table 2.

Table 29 Linear regression equation, correlation coefficient and method for retinol-like substances to determine the concentration

4. Method precision and recovery

And selecting negative samples of two common cosmetic formulations of cream and water to carry out recovery rate and precision tests. The sample is pretreated with the addition concentration of 500mg/kg and 100mg/kg respectively, 6 parts of each matrix type is prepared in parallel, the test is carried out according to the test conditions in the examples, the chromatograms are recorded, the recovery rate and the precision of 9 retinol substances are calculated, the specific test results are shown in fig. 6 and table 3, and the result shows that the precision result is 0.1% -1.4%; the recovery rate of the method is 85.3-116.1%, the relative standard deviation is 0.7-9.8%, and the detection requirement can be met.

TABLE 3 recovery and precision determination results

6. Stability test:

standard working solutions with the mass concentration of 2 levels (5 mg/L and 100 mg/L) are taken, the chromatographic peak areas of 9 retinol substances are respectively measured at 0, 8, 12, 18, 24 and 48 hours according to the test conditions in the embodiment of the invention, wherein RSD in 24 hours is used as daily stability, RSD in 48 hours is used as daily stability, and the test results are specifically shown in Table 6.

TABLE 6 stability test results for Standard working fluids

As can be seen from table 6 above: the 9 retinol substances are stable within 48 hours, so that the detection method provided by the invention has high stability and repeatability.

While the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art. Furthermore, embodiments of the invention and features of the embodiments may be combined with each other without conflict.

Claims

1. A method for detecting additives in cosmetics or raw materials thereof is characterized in that: the method comprises the following steps: detecting a liquid to be detected of a cosmetic or a cosmetic raw material by adopting a high performance liquid chromatography, wherein the additive comprises retinoic acid, isotretinoin, hydroxy pinacolone retinoic acid ester, retinaldehyde, retinol acetate, retinol palmitate, retinol propionate and retinol ester;

the chromatographic conditions are as follows: the chromatographic column is as follows: a C18 chromatographic column; the sample injection amount is as follows: 4-6 mu L; the flow rate is: 0.8-1.2 mL/min; the mobile phase is: mobile phase a is acetonitrile; mobile phase B is tetrahydrofuran; the mobile phase C is ammonium acetate solution, and elution is carried out in a gradient elution mode;

the elution procedure of the gradient elution is as follows:

21-41 min, wherein the volume percentage of the mobile phase A is 45%, the volume percentage of the mobile phase B is 45%, and the volume percentage of the mobile phase C is 10%;

41.01-46 min, 35% by volume of mobile phase A, 35% by volume of mobile phase B and 30% by volume of mobile phase C;

the pH value of the mobile phase is 6-7; the column temperature of the C18 chromatographic column is as follows: 24-36 ℃;

the liquid to be detected of the cosmetic or the cosmetic raw material comprises a sample solution; the sample solution is obtained by mixing and extracting a sample of cosmetics or cosmetic raw materials with an extraction solvent; the extracting solvent is a mixed solution of acetonitrile and tetrahydrofuran, and the volume ratio of acetonitrile to tetrahydrofuran in the mixed solution is (3-5) 1;

the detection wavelength is as follows: 325nm.

2. The method for detecting an additive in a cosmetic or a raw material thereof according to claim 1, wherein: the concentration of the mobile phase C is 4-6 mmol/L.

3. The method for detecting an additive in a cosmetic or a raw material thereof according to claim 1, wherein: the diameter of the C18 chromatographic column is 4-5 mm, the length of the C18 chromatographic column is 200-300 mm, and the particle size of the filler is 4-6 mu m.

4. A method for detecting an additive in a cosmetic or a raw material thereof according to any one of claims 1 to 3, characterized in that: the detector of the chromatograph is a PDA detector.