Fingerprint analysis method for identifying cosmetics based on HS-GC-IMS technology

Abstract

The invention discloses a fingerprint spectrum analysis method for identifying cosmetics based on an HS-GC-IMS technology, which comprises the following steps: carrying out gas chromatography-ion mobility spectrometry detection on cosmetic samples from different sources or in different batches by adopting headspace sampling to obtain GC-IMS spectrograms of volatile compounds of different samples; a Report plug-in in VOCal analysis software and a Galley Plot plug-in in LAV analysis software are used for statistical analysis, a two-dimensional top view and a fingerprint spectrogram are generated, and the change conditions of volatile compounds of different samples are compared. According to the invention, trace and trace volatile headspace components such as fragrance in solid, semi-solid and liquid cosmetics can be detected, a cosmetic authenticity identification and different-batch quality consistency research method is established, and the difference of fine characteristic components is visually compared, so that identification analysis is carried out; theoretical basis and data support are provided for cosmetic authenticity identification and quality difference research, quality control of production enterprises is promoted, and makeup use safety of consumers is guaranteed.

Description

Technical Field

[0001] The present invention relates to a fingerprint spectrum analysis method for identifying cosmetics based on HS-GC-IMS technology. Background Art

[0002] Cosmetics refer to chemical industrial products or fine chemical products that are applied, sprayed or otherwise distributed on any part of the human body surface, such as skin, hair, fingernails, lips, etc., for the purpose of cleaning, maintaining, beautifying, modifying and changing appearance, or correcting body odor and maintaining a good state. The prevalence of counterfeit and shoddy cosmetics not only disrupts the market order of honest operation, but also poses a potential threat to consumer health, thus posing new requirements for regulatory authorities to improve and enrich identification means.

[0003] In recent years, the research focus on cosmetics has mainly concentrated on the fields of the safety and efficacy of cosmetic products, mainly including the detection technology of restricted and prohibited substances required in product formulations, product efficacy, and regulatory standards, as well as human safety research. Currently, methods used for cosmetic detection, such as chromatography, atomic spectrometry, laser-induced breakdown spectroscopy, etc., are mainly used to analyze heavy metal content, organic esters, hormones, antibiotics, etc., lacking corresponding detection methods for the identification and quality control of cosmetics. Currently, the authenticity identification of cosmetics mainly focuses on "one look, two checks, and three verifications", namely labels and instructions, approval numbers, and relevant filing and registration information on government websites, relying more on human experience and lacking a scientific and systematic quality evaluation system.

[0004] Cosmetics are compound mixtures prepared by reasonably blending various raw materials. Commonly used oil-based raw materials, wax-based raw materials, hydrocarbon-based raw materials, and synthetic oil-based raw materials in cosmetics are a major type of raw materials for cosmetics. The main component ratios of high-quality imitation cosmetics are relatively close. Therefore, using conventional methods to test through single markers and multiple markers is not only complex in operation but also unable to effectively identify authenticity.

[0005] Therefore, it is very necessary to establish a simple, convenient, efficient and sensitive instrumental method for identification analysis and quality control.

[0006] Headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) is an emerging technology for detecting volatile components. It first undergoes primary separation in a gas chromatography column and then enters an ion migration tube. After the molecules to be tested are ionized in the ionization zone, they migrate to the Faraday disk for detection under the action of the electric field and the reverse drift gas to achieve secondary separation. HS-GC-IMS combines the advantages of high resolution of gas chromatography and high sensitivity of ion mobility spectrometry. It can quickly detect trace volatile organic compounds in samples without any special sample pretreatment. A three-dimensional GC-IMS spectrum of retention time, drift time, and signal intensity is constructed using headspace-gas chromatography-ion mobility spectrometry. The detected components are qualitatively and quantitatively analyzed using VOCal software. Multivariate statistical analysis methods including Gallery Plot, dynamic principal component analysis, PLS-DA method, and "nearest neighbor" fingerprint analysis are used to perform differential analysis of samples. In recent years, due to its advantages such as high sensitivity, this technology has begun to be applied in the fields of pharmacy, food science, and agriculture. It is widely favored at home and abroad in the field of food volatile flavor component analysis, such as vegetable oil identification and adulteration detection, fungus and mushroom soup flavor component analysis, flavor changes during wine fermentation, flavor substance detection and analysis of condiments, changes in volatile flavor substances during meat pickling, and analysis and detection of flavor compounds in fruits and vegetables during storage. In addition, it is widely used in the detection of Chinese medicine odor, such as identification of different varieties of Chinese medicine, identification of different harvesting periods, different drying methods, comparative analysis before and after processing, comparison of different processed products, identification of Chinese medicine from different origins, storage period research, etc. However, its application in cosmetics identification has not been reported. Summary of the invention

[0007] The present invention provides a fingerprint analysis method for identifying cosmetics based on headspace gas ion mobility spectrometry (HS-GC-IMS) technology. The present invention applies HS-GC-IMS to detect cosmetics for the first time, studies volatile organic compounds in cosmetics in the form of data visualization, and accurately distinguishes cosmetics through the differences in subtle characteristic components in the fingerprint, providing a certain theoretical basis and data support for the authenticity identification of cosmetics and the study of quality differences.

[0008] The technical solution adopted by the present invention is:

[0009] A fingerprint analysis method for identifying cosmetics based on HS-GC-IMS technology, comprising the following steps:

[0010] (1) For cosmetic samples from different sources or different batches, headspace sampling is performed, followed by gas chromatography-ion mobility spectrometry detection, to obtain GC-IMS spectra of volatile compounds of different cosmetic samples, and a Reporter plug-in in the VOCal analysis software provided by the GC-IMS instrument is used to generate a two-dimensional top view of the gas phase-ion migration of volatile compounds, and genuine cosmetics from regular sources are used as references, and the two-dimensional top views of the gas phase-ion migration of different cosmetic samples are compared using a difference comparison mode, and a comparison difference spectrum of volatile compounds is constructed to compare the differences in the content of volatile compounds of different samples;

[0011] (2) The Gallery Plot plug-in in the LAV analysis software was used to analyze the gas phase-ion migration two-dimensional top view of different cosmetic samples, and a fingerprint spectrum automatically generated from all detectable signal peaks in the gas phase-ion migration two-dimensional top view was obtained to compare the changes in volatile compounds in different cosmetic samples.

[0012] Furthermore, in step (1), the conditions for gas chromatography-ion mobility spectrometry detection are as follows: gas phase-ion mobility spectrometry unit: chromatographic column is MXT-5 (15m×0.53mm, 1μm), analysis time is 40min, column temperature is 60°C, carrier gas / drift gas N 2 , IMS temperature 45℃.

[0013] Furthermore, the conditions for headspace injection are: incubation temperature 60° C., incubation time 20 min, injection volume 500 μL, injection needle temperature 80° C., incubation speed 500 r / min.

[0014] Furthermore, the conditions of the gas chromatography are as follows: E1 drift gas volume flow rate: 150 mL / min within 0 to 40 min after injection; E2 gas carrier gas volume flow rate: 2 mL / min within 0 to 2 min after injection; 15 mL / min from 2 to 10 min; 100 mL / min from 10 to 20 min; and 100 mL / min from 20 to 40 min.

[0015] The IMS conditions were as follows: drift tube length: 98 mm; linear voltage in the tube: 500 V / cm; drift tube temperature: 45°C; drift gas N2; drift gas flow rate: 150 mL / min.

[0016] In the present invention, the cosmetic sample can be solid, semi-solid or liquid cosmetics. In the present invention, the cosmetic samples from different sources or different batches refer to cosmetics of the same brand and the same category but from different sources or different batches.

[0017] Furthermore, in step (1), according to the different gas chromatographic retention times and ion migration times of different volatile compounds in the gas phase-ion migration two-dimensional top view of different cosmetics, orthoketone C4 to C9 are selected as external standard references to calculate the retention index of each substance, and the built-in NIST database and IMS database are used to perform qualitative analysis on the volatile compounds in different samples.

[0018] Furthermore, in step (1), each sample is preferably tested multiple times in parallel to obtain multiple GC-IMS spectra for analysis. Generally, each sample is tested 2 to 5 times in parallel, preferably 3 times.

[0019] Furthermore, in step (2), the fingerprints are compared using the Gallery Plot plug-in to intuitively and quantitatively compare the characteristic differences of the fingerprints between different samples.

[0020] Furthermore, in the two-dimensional top view of gas phase-ion migration, the horizontal axis represents the migration time of the volatile compound relative to the reaction ion peak during IMS separation, and the vertical axis represents the retention time of the volatile compound during GC separation. The vertical line at the horizontal axis 1.0 is the normalized reaction ion peak, and each point on both sides of the reaction ion peak represents a volatile compound. The color represents the concentration of the substance, red represents high concentration, and blue represents low concentration.

[0021] In the comparative difference spectra of the volatile compounds, after deducting the reference from different cosmetic samples, if the volatile compounds of the two samples are the same, the subtracted background fades to white, red represents that the concentration of the substance is higher than that of the reference sample, and blue represents that the concentration of the substance is lower than that of the reference sample.

[0022] In the step (2), in the fingerprint spectrum automatically generated from all detectable signal peaks in the gas phase-ion migration two-dimensional top view, the horizontal axis is the detection signal peak of the volatile compound in the sample, and the vertical axis is the sample number. The darker the red, the higher the content of the component, and the darker the blue, the lower the content of the component.

[0023] Furthermore, the method also includes authenticating the cosmetics:

[0024] Authentic cosmetics from regular sources are used as references. The greater the difference in the comparison difference spectrum between the cosmetic sample to be tested and the reference, and the greater the difference in the signal peak in the fingerprint spectrum with the reference, the more it can be judged as a counterfeit.

[0025] Furthermore, in the authenticity identification, genuine cosmetics from regular sources are used as references, and the fingerprint spectrum is analyzed by using the Gallery Plot plug-in provided by the software. Products with a similarity lower than a preset value are judged to be imitations, and the preset value can be set between 60% and 85%.

[0026] The method of the present invention can also be used to analyze the quality consistency of different batches of cosmetics: for different batches of cosmetics, the quality consistency analysis can be performed based on the differences in the types and contents of volatile compounds in different samples to control the product quality.

[0027] The principle of the present invention is that the quality of cosmetic raw materials of genuine and imitation products is uneven, the residual trace volatiles are different, and the main characteristic fragrance components and other trace components of cosmetics are different. Therefore, the present invention uses HS-GC-IMS to detect cosmetics for the first time, studies the volatile organic compounds in cosmetics in the form of data visualization, and accurately distinguishes cosmetics through the differences in subtle characteristic components in the fingerprint spectrum.

[0028] The beneficial effects of the present invention are:

[0029] The headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) technology is used to detect trace and minute amounts of volatile headspace components such as fragrance in solid, semi-solid and liquid cosmetics, and a method for studying the authenticity of cosmetics and the consistency of quality between different batches is established. By visually comparing difference spectra and fingerprint maps, the differences in subtle characteristic components are intuitively compared, thereby performing identification and analysis. This provides a certain theoretical basis and data support for the authenticity identification of cosmetics and the study of quality differences, and can be applied to market monitoring and testing by government departments, promote quality control of manufacturers, and ensure the safety of consumers' use of cosmetics. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 These are the headspace-gas chromatography-ion migration spectra of the 10 essence samples of Example 1, wherein Figure A is a two-dimensional top view of the gas phase-ion migration of samples from the counter and the online flagship store, Figure B is a two-dimensional top view of the gas phase-ion migration of samples from the counter and other online stores, and Figure C is a difference spectrum.

[0031] Figure 2 The fingerprints of the cosmetic volatile compounds of the 10 essence samples in Example 1 are shown in FIG.

[0032] Figure 3 It is the headspace-gas chromatography-ion migration spectrogram of 7 kinds of skin softening water samples in Example 2, wherein, the upper figure is the gas phase-ion migration two-dimensional top view of 7 kinds of samples, and the lower figure is the difference spectrum.

[0033] Figure 4 This is the fingerprint of the volatile compounds of 7 skin softening water samples in Example 2.

[0034] Figure 5Headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) spectra of two kinds of primer samples in Example 3. Among them, the upper figure is the two-dimensional top view of gas-phase-ion mobility, and the lower figure is the difference spectrum.

[0035] Figure 6 Fingerprint of volatile compounds of two kinds of primer samples in Example 3.

[0036] Figure 7 Headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) spectra of seven kinds of cream samples in Example 4. Among them, the upper figure is the two-dimensional top view of gas-phase-ion mobility, and the lower figure is the difference spectrum.

[0037] Figure 8 Fingerprint of volatile compounds of seven kinds of cream samples in Example 4.

[0038] Figure 9 Headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) spectra of two kinds of facial cleanser samples in Example 5. Among them, the upper figure is the two-dimensional top view of gas-phase-ion mobility, and the lower figure is the difference spectrum.

[0039] Figure 10 Fingerprint of volatile compounds of two kinds of facial cleanser samples in Example 5.

[0040] Figure 11 Headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) spectra of six kinds of concealer samples in Example 6. Among them, the upper figure is the two-dimensional top view of gas-phase-ion mobility, and the lower figure is the difference spectrum.

[0041] Figure 12 Fingerprint of volatile compounds of six kinds of concealer samples in Example 6. Detailed implementation mode

[0042] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with examples and drawings. However, the content of the present invention is not limited to the following examples only, and the examples should not be regarded as a limitation of the protection scope of the present invention.

[0043] Example 1

[0044] 1 Instruments and reagents

[0045] 1.1 Instruments

[0046] Gas chromatography-ion mobility spectrometry (Shandong Haineng Scientific Instruments Co., Ltd.); XP204 electronic balance (Mettler Toledo Instruments (Shanghai) Co., Ltd.).

[0047] 2 Methods

[0048] 2.1 Detection conditions

[0049] Gas phase-ion mobility spectrometry unit: chromatographic column is MXT-5 (15m×0.53mm, 1μm), analysis time is 40min, column temperature is 60℃, carrier gas / drift gas is N 2 , IMS temperature 45℃. Automatic headspace injection unit: incubation temperature 60℃, incubation time 20min, injection volume 500μL, injection needle temperature 80℃, incubation speed 500r / min. Gas chromatography conditions: E1 drift gas volume flow rate 0~40min, 150mL / min; E2 gas phase carrier gas volume flow rate 0~2min, 2mL / min; 2~10min, 15mL / min; 10~20min, 100mL / min; 20~40min, 100mL / min.

[0050] The IMS conditions were as follows: drift tube length: 98 mm; linear voltage in the tube: 500 V / cm; drift tube temperature: 45°C; drift gas N2; drift gas flow rate: 150 mL / min.

[0051] 2.2 Sample determination

[0052] Accurately weigh 0.5 g of essence and place it in a 20 mL headspace injection bottle. Incubate at 60°C for 20 min and perform the determination according to the method in “2.1”.

[0053] 2.3 Data processing methods

[0054] Data collection and analysis: VOCal software that comes with the flavor analyzer; fingerprint analysis: The Gallery Plot software that comes with the flavor analyzer;

[0055] 3 Results and analysis

[0056] 3.1 Comparison of volatile substances in 10 serums purchased from different sources (1-6 are genuine products, 7-10 are counterfeit products)

[0057] The Reporter plug-in in the VOCal analysis software that comes with the GC-IMS instrument is used to generate a two-dimensional top view of the gas phase-ion migration of volatile compounds. The red vertical line at the horizontal axis 1.0 is the reaction ion peak (normalized). Each point on the right side of the reaction ion peak represents a volatile compound, and the color represents the signal intensity of a single compound. Red represents high intensity, and blue represents low intensity. Figure 1 It can be seen that most signals have a retention time of 100 to 1400 seconds and a drift time of 1.0 to 2.5 seconds. Figure 1 -A, see counters and other sources Figure 1 -B. By Figure 1 -A and Figure 1As can be seen from -B, although the production areas and specifications of the samples in the special counters and flagship stores are not exactly the same, the volatile compounds are relatively similar, while the other several samples are quite different from the samples in the special counters. From Figure 1 As shown, the two-dimensional spectrum of the sample purchased at the special counter (RAW) was selected as the reference, and the differential spectra of the remaining 9 samples (XZP2, XZP3, XZP4, XZP5, XZP6, XZP7, XZP8, XZP9, and XZP10) after subtracting the reference are as shown in Figure 1 Figure C. The subtracted background is white. Red indicates that the content of volatile components is higher than the reference, and blue indicates that the content of volatile components is lower than the reference. From the differential spectra, it can be seen that there are more white parts in the sample spectra of XZP2, XZP3, XZP4, XZP5, and XZP6, and they are more similar, indicating that the samples purchased at the special counters and flagship stores, regardless of their specifications, have a relatively high similarity. Among them, more and more red and blue spots appear in XZP7, XZP8, XZP9, and XZP10, indicating that the other 4 cosmetics from different online shopping platforms are quite different from the genuine products at the special counters.

[0058] 3.2 Fingerprint analysis of flavor components

[0059] In order to further analyze and compare the differences in flavor components of cosmetics from different sources, the fingerprint spectra of flavor components of cosmetics from different sources were constructed using the Gallery Plot plug-in in the LAV analysis software, and the results are as shown in Figure 2 Figure. Figure 2 Each row in the figure represents 1 sample. Three fingerprint spectra were obtained by parallel determination of each cosmetic three times. Each column represents the content level of the same flavor component in the cosmetic samples from different sources. The darker the red, the more the content of the component, and the darker the blue, the less the content of the component. As can be seen from Figure 2 Figure, the cosmetic samples from different sources have both their own characteristic signals and the same common signals. For example, in the samples at the special counters and flagship stores with numbers 17, 1, 19, 10, 78, 40, 12, 21, 81, 14, 37, 5, 6, 82, 76, 75, 63, 72, 65, 23, 71, 79, 2, 80, 54, 52, 68, 43, 83, 86, 60, 70, 74, 55, 85, 56, 66, 84, 87, 73, 58, 57, the main volatile substances in regions B, C, D, and E are different. In region B, there are mainly 13, 7, 15, 11, 22, 67, 51, 61, 39, 46, 52, 38, 77. In region C, there are mainly 3, 44, 49, 50, 47, 4, 48, 62, 16, 25, 69. In region D, there are mainly 69, 8, 9, 31, 26, 34, 32, 30, 42, 18, 27, 41. In region E, there are mainly 45, 35, 33, 20, 24, 28, 29, 36.

[0060] From the similarity results of the fingerprint maps, it can be seen that the similarity of the genuine product is above 85%, while the similarity of the counterfeit product is below 60%. Therefore, setting the threshold for authenticity identification to 80% can effectively distinguish essences from different sources.

[0061] According to the different gas chromatography retention times and ion migration times of different volatile compounds, the retention index of each substance was calculated by selecting orthoketone C4~C9 as external standard reference. The flavor components were qualitatively analyzed using the built-in NIST database and IMS database. The results of qualitative analysis of substances are shown in Table 1. Figure 2 The numbers correspond to the aroma substances in Table 1.

[0062] Table 1 Qualitative analysis results of 83 compounds (D or d represents dimer, M or m represents monomer)

[0063]

[0064]

[0065]

[0066]

[0067] Example 2

[0068] Toner samples (1, 2, 4 are genuine, 3, 5, 6, 7 are fake)

[0069] Determination of samples

[0070] Accurately weigh 0.5 g of softening water and place it in a 20 mL headspace injection bottle, incubate at 60° C. for 20 min, and perform the determination according to the method in “2.1” of Example 1.

[0071] Data processing methods

[0072] Data collection and analysis: VOCal software that comes with the flavor analyzer; fingerprint analysis: The Gallery Plot software that comes with the flavor analyzer; the headspace-gas chromatography-ion mobility spectra of 7 kinds of skin lotion samples are as follows Figure 3 As shown in the figure, the upper figure is a two-dimensional top view of the gas phase-ion migration of 7 samples, and the lower figure is a difference spectrum. The fingerprints of volatile compounds of 7 skin softening water samples are shown in Figure 4 The detected compounds were qualitatively analyzed.

[0073] The results showed that a total of 40 compounds were detected and 33 compounds were identified, as shown in Table 2. The authentic products all contained 10, 1, 17, 2, 4, 6, 5, 12, 31, 16, 18, and 19 compounds, while the compounds in the four counterfeit products were different.

[0074] Figure 4 The results of the fingerprint map show that the similarity of the genuine product is above 70%, while the similarity of the counterfeit product is below 41%. Therefore, setting the threshold for authenticity identification to 65% can effectively distinguish essences from different sources.

[0075] Table 2

[0076]

[0077]

[0078] Example 3

[0079] Primer (1 is genuine, 2 is fake)

[0080] Determination of samples

[0081] Accurately weigh 0.5 g of primer and place it in a 20 mL headspace injection bottle, incubate at 60° C. for 20 min, and perform the measurement according to the method in “2.1” of Example 1.

[0082] Data processing methods

[0083] Data collection and analysis: VOCal software that comes with the flavor analyzer; fingerprint analysis: The Gallery Plot software that comes with the flavor analyzer; the headspace-gas chromatography-ion mobility spectra of the two primer samples are shown in Figure 2. Figure 5 As shown in the figure, the upper figure is a two-dimensional top view of gas phase-ion migration, and the lower figure is a difference spectrum. The fingerprints of volatile compounds of the two primer samples are shown in Figure 6 And conduct qualitative analysis.

[0084] The results showed that 36 compounds were detected and 30 compounds were identified, as shown in Table 3. The common compounds were 6, 5, 8, 14, 7, 26, 34, and 35, the authentic products had compounds 1, 2, 4, 9, 10, 15, 16, 17, 18, 21, 22, 23, 24, 25, 27, 28, 29, 30, 31, 32, 33, and 36, and the counterfeit products had compounds 20, 11, 19, 3, 13, and 12.

[0085] Figure 6The results of the fingerprint spectrum show that the similarity between the counterfeit product and the genuine product is only a little over 30%, and the method of the present invention can effectively distinguish primer products from different sources.

[0086] Table 3

[0087]

[0088]

[0089] Example 4

[0090] Facial cream (1, 2, 3, 5 are genuine products, 6, 7 are counterfeit products)

[0091] Determination of samples

[0092] Precisely weigh 0.5 g of facial cream and place it in a 20-mL headspace vial. Incubate at 60 °C for 20 min, and perform the determination according to the method described in item "2.1" of Example 1.

[0093] Data processing method

[0094] Data collection and analysis: VOCal software included with the flavor analyzer; fingerprint spectrum analysis: Gallery Plot software included with the flavor analyzer; The headspace-gas chromatography-ion mobility spectrometry diagrams of 7 facial cream samples are as Figure 7 shown. The upper diagram is the two-dimensional top view of gas phase-ion mobility, and the lower diagram is the difference spectrum. The fingerprint spectra of the volatile compounds of 7 facial cream samples are as Figure 8 shown. And qualitative analysis is carried out.

[0095] The results show that a total of 37 compounds are detected, and 23 compounds are identified, as shown in Table 4 below. The main compounds detected in the genuine products are 26, 2, 5, 17, 14, 24, 21, 25, 19, 20, 18, 29, 11, 22, etc., while the compounds in the counterfeit products are 7, 36, 15, 12, 33, 27, 32, etc.

[0096] Figure 8 The results of the fingerprint spectrum show that the similarity of the genuine products is all above 78%, and the similarity of the counterfeit products is all below 45%. This method can effectively distinguish facial creams from different sources.

[0097] Table 4

[0098]

[0099] Example 5

[0100] Facial cleanser (1 is the genuine product, 2 is the counterfeit product)

[0101] Determination of samples

[0102] Accurately weigh 0.5 g of facial cleanser and place it in a 20 mL headspace vial. Incubate at 60 °C for 20 min, and perform the determination according to the method described in item "2.1" of Example 1.

[0103] Data processing method

[0104] Data collection and analysis: VOCal software included with the flavor analyzer; Fingerprint analysis: Gallery Plot software included with the flavor analyzer; The headspace-gas chromatography-ion mobility spectrometry diagrams of 2 facial cleanser samples are as Figure 9 shown. The upper diagram is the two-dimensional top view of gas-phase-ion mobility, and the lower diagram is the difference diagram. The fingerprint diagrams of the volatile compounds of 2 facial cleanser samples are as Figure 10 shown. And qualitative analysis is performed.

[0105] The results show that a total of 63 compounds are detected, and 35 compounds are identified, as shown in Table 5 below. The main compounds detected in the genuine product are compounds 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 29, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 59, 6, 61, 62, 63, etc., while the compounds in the counterfeit product are compounds 30, 31, 32, 33, 34, 35, 56, etc.

[0106] Figure 10 The results of the fingerprint diagrams show that the similarity between the counterfeit product and the genuine product is below 25%, and this method can effectively distinguish facial cleansers from different sources.

[0107] Table 5

[0108]

[0109]

[0110] Example 6

[0111] Concealer (1-3 are genuine products, 4-6 are counterfeit products)

[0112] Determination of samples

[0113] Accurately weigh 0.5 g of pressed powder and place it in a 20 mL headspace vial. Incubate at 60 °C for 20 min, and perform the determination according to the method described in item "2.1" of Example 1.

[0114] Data processing method

[0115] Data collection and analysis: VOCal software included with the flavor analyzer; Fingerprint analysis: Gallery Plot software included with the flavor analyzer; The headspace-gas chromatography-ion mobility spectrometry diagrams of 6 concealer samples are as Figure 11 shown. The upper diagram is the two-dimensional top view of gas-phase-ion mobility, and the lower diagram is the difference diagram. The fingerprint diagrams of the volatile compounds of 6 concealer samples are as Figure 12 shown. And qualitative analysis is carried out.

[0116] The results show that a total of 52 compounds are detected, and 33 compounds are identified, as shown in Table 6 below. The common compounds are 11, 5, 4, 9, 13, 17, 18, 22. The main compounds detected in the genuine products are 1, 2, 3, 6, 7, 8, 10, 12, 14, 15, 16, 20, 25, 34, 35, 37, 38, 39, 40, 41, etc., while the compounds in the counterfeit products are 19, 21, 23, 24, 47, 45, 26, 28, 29, 30, 31, 32, 33, 36, 42, 43, 44, 46, 48, 49, 50, 51, etc.

[0117] Figure 12 The results of the fingerprint diagrams show that the similarity between the counterfeit products and the genuine products is below 50%. This method can effectively distinguish concealers from different sources.

[0118] Table 6

[0119]

Claims

1. A fingerprint analysis method for identifying cosmetics based on HS-GC-IMS technology, characterized in that: The method comprises the following steps: (1) For cosmetic samples from different sources or different batches, headspace sampling is performed, followed by gas chromatography-ion mobility spectrometry detection, to obtain GC-IMS spectra of volatile compounds of different cosmetic samples, and a Reporter plug-in in the VOCal analysis software provided by the GC-IMS instrument is used to generate a two-dimensional top view of the gas phase-ion migration of volatile compounds, and genuine cosmetics from regular sources are used as references, and the two-dimensional top views of the gas phase-ion migration of different cosmetic samples are compared using a difference comparison mode, and a comparison difference spectrum of volatile compounds is constructed to compare the differences in the content of volatile compounds of different samples; (2) The Gallery Plot plug-in in the LAV analysis software was used to analyze the gas phase-ion migration two-dimensional top view of different cosmetic samples, and a fingerprint spectrum automatically generated from all detectable signal peaks in the gas phase-ion migration two-dimensional top view was obtained to compare the changes in volatile compounds in different cosmetic samples.

2. The method according to claim 1, characterized in that In step (1), the conditions for gas chromatography-ion mobility spectrometry detection are as follows: gas phase-ion mobility spectrometry unit: the chromatographic column is MXT-5, the specification is 15m×0.53mm, 1μm, the analysis time is 40min, the column temperature is 60°C, the carrier gas / drift gas is N2, and the IMS temperature is 45°C.

3. The method according to claim 1, characterized in that In step (1), the conditions for headspace injection are: incubation temperature 60°C, incubation time 20 min, injection volume 500 μL, injection needle temperature 80°C, and incubation speed 500 r / min.

4. The method according to claim 1, characterized in that In step (1), the gas chromatography conditions are as follows: E1 drift gas volume flow rate: 150 mL / min within 0 to 40 min after injection; E2 gas phase carrier gas volume flow rate: 2 mL / min within 0 to 2 min after injection; 15 mL / min within 2 to 10 min; 10~20min, 100mL / min; 20~40min, 100mL / min.

5. The method according to claim 1, characterized in that In step (1), the IMS conditions are: drift tube length: 98 mm; linear voltage in the tube: 500 V / cm; drift tube temperature: 45° C.; drift gas N 2 ; drift gas flow rate: 150 mL / min.

6. The method according to claim 1, characterized in that In step (1), according to the different gas chromatographic retention times and ion migration times of different volatile compounds in the gas phase-ion migration two-dimensional top view of different cosmetics, and the orthoketone C4~C9 is selected as the external standard reference to calculate the retention index of each substance, and the volatile compounds in different samples are qualitatively analyzed using the built-in NIST database and IMS database.

7. The method according to claim 1, characterized in that In step (2), the fingerprints are compared using the Gallery Plot plug-in to intuitively and quantitatively compare the characteristic differences of the fingerprints between different samples.

8. The method according to claim 1, characterized in that The method comprises step (3): authenticating and determining the authenticity of the cosmetics: Taking genuine cosmetics from regular sources as reference, the greater the difference in the comparison difference spectrum between the cosmetic sample to be tested and the reference, and the greater the difference in the signal peak in the fingerprint spectrum with the reference, the more it is judged to be a counterfeit.

9. The method according to claim 8, characterized in that In the authenticity identification, genuine cosmetics from regular sources are used as references, and the software's built-in Gallery Plot plug-in is used to perform similarity calculation and analysis in the fingerprint spectrum. Products with similarities lower than a preset value are judged to be counterfeits.

10. The method according to claim 1, characterized in that The method further comprises: performing quality consistency analysis on different batches of cosmetics by comparing the differences in the types and contents of volatile compounds in different samples to control product quality.

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