On-site rapid detection device and method for weakly polar substances in cosmetics

Abstract

The invention discloses an on-site rapid detection device for weak polar substances in cosmetics, which comprises a solid phase microextraction probe (1), a metal wire (2), a dual-channel theta borosilicate glass capillary spray emitter (3) and a mass spectrometer (4), the dual-channel theta borosilicate glass capillary spray emitter (3) comprises two channels, a desorption solvent and a derivatization reagent are respectively arranged in the two channels, the rear ends of the phase microextraction probe (1) and the metal wire (2) are connected with the mass spectrometer (4), and the front ends of the phase microextraction probe (1) and the metal wire (2) are respectively arranged in the desorption solvent and the derivatization reagent. According to the device and the method, a polyaniline / multi-walled carbon nanotube solid-phase microextraction probe is used for extracting a target substance, and an online derivatization reaction of the target substance is realized through a dual-channel theta borosilicate glass capillary spray emitter; and a small portable mass spectrometer is combined to establish an on-site rapid analysis method for the four forbidden sex hormones in the cosmetic sample, so that technical support can be provided for on-site rapid detection and supervision and law enforcement of cosmetic quality safety.

Description

Technical Field

[0001] The present invention relates to the fields of cosmetics and analytical chemistry, and in particular to an on-site rapid analysis device and method for weakly polar substances in cosmetics. Background Art

[0002] With the continuous emergence of new raw materials, technologies, and products, the quality and safety of cosmetics has become a growing concern among consumers, placing higher demands on detection technologies. The addition of sex hormones to cosmetics can impart whitening, freckle removal, and anti-wrinkle benefits. However, long-term use of products containing sex hormones can lead to skin allergies, dermatitis, and ultimately metabolic disorders. Consequently, my country's "Technical Specifications for Safety of Cosmetics" (2015 edition) explicitly lists 63 hormonal ingredients, including sex hormones, as prohibited ingredients in cosmetics. Currently, the main methods for detecting sex hormones in cosmetics include immunochromatography, high-performance liquid chromatography, and high-performance liquid chromatography-tandem mass spectrometry. Sex hormones such as estrone, epitestosterone, testosterone, and androstenedione lack sufficient sensitivity due to their low ionization efficiency. These hormones are typically derivatized and analyzed using high-performance liquid chromatography-tandem mass spectrometry. However, this method requires complex sample pretreatment, long detection cycles, and the reliance on large-scale laboratory analytical equipment. With the booming cosmetics industry and increasing detection throughput, traditional high-performance liquid chromatography-tandem mass spectrometry is no longer sufficient for rapid on-site testing. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a simple, rapid, real-time and efficient device and method for on-site rapid analysis of weak polar substances in cosmetics.

[0004] A device for rapid on-site detection of weakly polar substances in cosmetics comprises a solid-phase microextraction probe, a metal wire, a dual-channel theta borosilicate glass capillary spray emitter, and a mass spectrometer. The dual-channel theta borosilicate glass capillary spray emitter comprises two channels, each containing a desorption solvent and a derivatization reagent. The rear ends of the solid-phase microextraction probe and the metal wire are connected to the mass spectrometer, while the front ends are disposed in the desorption solvent and the derivatization reagent, respectively.

[0005] In the on-site rapid detection device for weakly polar substances in cosmetics described in the present invention, the solid phase microextraction probe coating is polyaniline / multi-walled carbon nanotubes.

[0006] In the on-site rapid detection device for weakly polar substances in cosmetics described in the present invention, the metal wire is a copper wire.

[0007] The on-site rapid detection device for weakly polar substances in cosmetics described in the present invention, wherein the mass spectrometer is a Miniβ small portable mass spectrometer, and the solid phase microextraction probe and the metal wire are connected to the high voltage source of the Miniβ small portable mass spectrometer through a metal wire.

[0008] The on-site rapid detection device for weakly polar substances in cosmetics of the present invention, wherein the tip size of the dual-channel θ borosilicate glass capillary spray emitter is 60 μm, and the tip of the dual-channel θ borosilicate glass capillary spray emitter is placed 1.0 cm in front of the mass spectrometer inlet;

[0009] The length of the dual-channel θ borosilicate glass capillary spray emitter is 6 cm, the length of the metal wire and the solid phase microextraction probe is 5 cm, and the depth of the metal wire and the solid phase microextraction probe inserted into the dual-channel θ borosilicate glass capillary spray emitter is 4 cm.

[0010] The on-site rapid detection method for weak polar substances in cosmetics using the on-site rapid detection device for weak polar substances in cosmetics of the present invention comprises the following steps:

[0011] A solid-phase microextraction probe is immersed in an aqueous cosmetic sample for adsorption extraction. After extraction, the probe is inserted into a channel containing a desorption solvent in a dual-channel θ-borosilicate glass capillary spray emitter. A metal wire is inserted into another channel containing a derivatization reagent. The dual-channel θ-borosilicate glass capillary spray emitter is placed in front of the mass spectrometer inlet. An ionization voltage is applied, and the two liquids form spray droplets, which then collide to complete the online derivatization reaction. The resulting derivatization reaction products are then detected by the mass spectrometer.

[0012] The present invention provides a method for rapid on-site detection of weakly polar substances in cosmetics, wherein the preparation method of the dual-channel θ-borosilicate glass capillary spray emitter comprises the following steps: using a dual-channel θ-borosilicate glass capillary as a preparation material, drawing the capillary using a microelectrode drawing instrument, setting the electrode heating temperature to 760°C, the pulling force to 0N, the heating rate to 20°C / s, the delay time to 4s, the pressure to 400kPa, and the number of cycles to 1; a complete dual-channel θ-borosilicate glass capillary can be prepared into two disposable dual-channel θ-borosilicate glass capillary spray emitters.

[0013] The on-site rapid detection method for weakly polar substances in cosmetics of the present invention, wherein the solid phase microextraction probe is a polyaniline / multi-walled carbon nanotube extraction probe, is prepared by the following steps:

[0014] A stainless steel needle, cleaned with acetone, methanol, and deionized water and then air-dried, was used as a working electrode, a platinum wire as an auxiliary electrode, and an Ag / AgCl wire as a reference electrode. The electrolyte solution contained 0.5 mol / L sulfuric acid, 0.1 mol / L aniline monomer, and a 0.002% multi-walled carbon nanotube solution. The stainless steel needle was placed vertically and immersed in the electrolyte solution to a depth of 2 cm. Electrochemical deposition was performed using cyclic voltammetry with a potential range of -0.2 V to 0.9 V, a scan rate of 20 mV / s, and 15 cycles. The prepared probe was dried and cooled to room temperature for later use.

[0015] The specific adsorption extraction process includes the following steps:

[0016] The cosmetic sample was placed on a magnetic stirrer, and a polyaniline / multi-walled carbon nanotube probe was immersed in the sample for solid-phase microextraction of the target substance. The magnetic stirrer speed was set at 200 r / min, the extraction temperature was set at 40°C, and the extraction time was set at 2 min. After the extraction was completed, the polyaniline / multi-walled carbon nanotube probe was inserted into the channel containing the desorption solvent of a dual-channel θ borosilicate glass capillary spray emitter, and the metal wire was inserted into the other channel containing the derivatization reagent. The electrospray voltage was applied, and the target substance was desorbed from the probe to form an electrospray, which underwent an online derivatization reaction with the hydroxylamine spray.

[0017] In the on-site rapid detection method for weakly polar substances in cosmetics described in the present invention, the desorption solvent is methanol, the derivatization reagent is hydroxylamine, the concentration is 100 mM, and the addition amount of both is 10 μL.

[0018] The on-site rapid detection method for weak polar substances in cosmetics of the present invention, wherein the weak polar substances are estrone, epitestosterone, testosterone and androstenedione;

[0019] The analysis conditions of the Miniβ portable mass spectrometer are as follows: positive ionization mode, spray voltage 3.5 kV, injection time 40 ms, mass scan range m / z 50-500, and parallel injection number 3; the adduct mode, derivatization product parent ion, daughter ion and collision voltage of the four weakly polar substances are shown in Table 1:

[0020] Table 1 Parameters of small portable mass spectrometry analysis of four weakly polar substances

[0021]

[0022] Note: *Quantitative ion.

[0023] The on-site rapid detection device for weak polar substances in cosmetics of the present invention differs from the prior art in that:

[0024] The present invention provides an on-site rapid detection device and method for weakly polar substances in cosmetics. The device and method utilize a polyaniline / multi-walled carbon nanotube solid-phase microextraction probe to extract the target substances, and a dual-channel theta borosilicate glass capillary spray emitter to achieve an online derivatization reaction of the target substances. Furthermore, the device and method are combined with a small portable mass spectrometer to establish an on-site rapid analysis method for four banned sex hormones in cosmetic samples. This method can provide technical support for on-site rapid testing and supervision and law enforcement of cosmetics quality and safety.

[0025] The present method requires no sample pretreatment. A dual-channel theta borosilicate glass capillary spray emitter serves as the nanoliter extraction electrospray ionization source. The extracted probe is inserted into the methanol channel of the theta borosilicate glass capillary. Ionization is then applied at high pressure, and the four sex hormones are desorbed and formed into spray droplets. These droplets then undergo an online derivatization reaction with hydroxylamine droplets generated in the other channel. The reaction products are then directly analyzed by a small portable mass spectrometer. The detection limits for the four weakly polar substances ranged from 10 to 20 ng / mL, and the limits of quantification ranged from 20 to 50 ng / mL. Average spiked recoveries ranged from 84.6% to 107.8%, with relative standard deviations of 4.1 to 11.6%. Compared to the method without derivatization, the mass spectrometric signals of the four target substances were enhanced by 3 to 15 times. This method is simple, rapid, efficient, and sensitive, making it suitable for the on-site rapid analysis of weakly polar sex hormones in cosmetics.

[0026] The on-site rapid detection device for weak polar substances in cosmetics of the present invention will be further described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the structure of the on-site rapid detection device for weak polar substances in cosmetics of the present invention;

[0028] Figure 2 Schematic diagram of the process of the on-site rapid detection method of weak polar substances in cosmetics of the present invention;

[0029] Figure 3 Schematic diagram of the tip structure of the dual-channel θ borosilicate glass capillary spray emitter in the present invention;

[0030] Figure 4 This is a diagram showing the optimization results of the solid phase microextraction experimental conditions in the present invention;

[0031] Figure 5 The derivatization reaction mechanism and the target substance secondary mass spectrum of the present invention; wherein: A-derivation reaction mechanism, B-estrone, C-epitestrone, D-testosterone, E-androstenedione;

[0032] The translations of all English words appearing in the drawings of the present invention are as follows:

[0033] Intensity: response intensity; Stirring temperature: extraction temperature; Stirring time: extraction time; Stirring rate: rotation speed; Relative abundance: relative abundance; Estrone: estrone; Epitestoster: epitestosterone; Testosterone: testosterone; Androstenedio: androstenedione; m / z: mass-to-charge ratio. DETAILED DESCRIPTION

[0034] 1. Experimental part

[0035] 1.1 Main instruments and devices

[0036] P-1000 microelectrode pulling apparatus (Sutter, USA); Miniβ portable mass spectrometer (55 cm × 24 cm × 30 cm, mass 22 kg, power ≤ 100 W, Beijing Qingpu Technology Co., Ltd.); Scope.A1 optical microscope (ZEISS, Germany); Milli-Q ultrapure water analyzer (Millipore, USA); HS10 magnetic stirrer (IKA, Germany); ML503 analytical balance (METTER TOLEDO, Switzerland); θ borosilicate glass capillaries (1.5 mm outer diameter, 1.02 mm inner diameter, 0.2 mm diaphragm, World Precision Instruments, USA); metal wire (copper wire, 0.2 mm diameter, Beijing October New Materials Technology Co., Ltd.); stainless steel needle (0.16 mm outer diameter, 5 cm long, Beijing Zhongyan Taihe Medical Instrument Co., Ltd.)

[0037] like Figure 1 As shown, the on-site rapid detection device for weak polar substances in cosmetics includes a solid phase microextraction probe 1, a metal wire 2, a dual-channel θ borosilicate glass capillary spray emitter 3 and a mass spectrometer 4. The dual-channel θ borosilicate glass capillary spray emitter 3 includes two channels, in which a desorption solvent and a derivatization reagent are respectively arranged. The rear ends of the solid phase microextraction probe 1 and the metal wire 2 are connected to the mass spectrometer 4, and the front ends are respectively arranged in the desorption solvent and the derivatization reagent.

[0038] The solid-phase microextraction probe 1 is coated with polyaniline / multi-walled carbon nanotubes, and the metal wire 2 is copper. The mass spectrometer 1 is a Miniβ portable mass spectrometer. The solid-phase microextraction probe 1 and the metal wire 2 are connected to the high-voltage source of the Miniβ portable mass spectrometer via metal wires. The tip of the dual-channel θ borosilicate glass capillary spray emitter 3 is 60 μm and is placed 1.0 cm in front of the inlet of the mass spectrometer 4.

[0039] The length of the dual-channel θ borosilicate glass capillary spray emitter 3 is 6 cm, the length of the metal wire 2 and the solid phase microextraction probe 1 is 5 cm, and the depth of the metal wire 2 and the solid phase microextraction probe 1 into the dual-channel θ borosilicate glass capillary spray emitter 3 is 4 cm to ensure the experimental effect.

[0040] An example of a wire connection method is as follows: the metal wire is a high-voltage power line extending from the inside of the instrument, one end of which is connected to the circuit system of the mass spectrometer 4, and the other end is connected to an alligator clip. The solid phase microextraction probe 1 and the metal wire 2 are simultaneously connected to the metal wire through the alligator clip.

[0041] 1.2 Main materials and reagents

[0042] Estrone, epitestosterone, testosterone, and androstenedione standards (purity ≥96%, Beijing Tanmo Quality Inspection Technology Co., Ltd.); methanol (chromatographic grade, Fisher, USA); all other reagents were of analytical grade; multi-walled carbon nanotube solution (Jiangsu Xianfeng Nanomaterial Technology Co., Ltd., mass concentration 9.4%); all cosmetic samples were purchased from local supermarkets or e-commerce platforms.

[0043] 1.3 Experimental methods

[0044] 1.3.1 Preparation of polyaniline / multi-walled carbon nanotube extraction probe

[0045] A stainless steel needle, cleaned with acetone, methanol, and deionized water, and then air-dried, served as the working electrode. A platinum wire served as the auxiliary electrode, and an Ag / AgCl wire served as the reference electrode. The electrolyte solution contained 0.5 mol / L sulfuric acid, 0.1 mol / L aniline monomer, and a 0.002% multi-walled carbon nanotube solution. The stainless steel needle was placed vertically and immersed in the electrolyte solution to a depth of 2 cm. Electrochemical deposition was performed using cyclic voltammetry, with a potential range of -0.2 V to 0.9 V, a scan rate of 20 mV / s, and 15 cycles. The prepared probe was dried and cooled to room temperature before use.

[0046] in:

[0047] Stainless steel needle (outer diameter 0.16 mm, length 5 cm, Beijing Zhongyan Taihe Medical Instrument Co., Ltd.);

[0048] Multi-walled carbon nanotube solution was purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd. with a mass concentration of 9.4%. Before use, it was diluted with deionized water to a concentration of 0.02%.

[0049] Prepare the electrolyte solution by diluting concentrated sulfuric acid with deionized water to create a 5 mol / L sulfuric acid solution. Also, prepare a 1 mol / L aniline solution with deionized water. Add 1 mL of the 5 mol / L sulfuric acid solution, 1 mL of the 1 mol / L aniline solution, and 1 mL of the 0.02% multi-walled carbon nanotube solution to 7 mL of deionized water, followed by stirring. The electrolyte solution is formed.

[0050] 1.3.2 Preparation of a dual-channel θ borosilicate glass capillary spray emitter

[0051] A dual-channel θ-borosilicate glass capillary was used as the fabrication material for the dual-channel θ-borosilicate glass capillary spray emitter, pulled using a microelectrode puller. The electrode heating temperature was set to 760°C, the pulling force was 0 N, the heating rate was 20°C / s, the delay time was 4 seconds, the pressure was 400 kPa, and the number of cycles was 1. From one complete dual-channel θ-borosilicate glass capillary, two disposable dual-channel θ-borosilicate glass capillary spray emitters can be fabricated simultaneously.

[0052] 1.3.3 Extraction and desorption of target substances

[0053] The cosmetic sample is placed on a magnetic stirrer, and a polyaniline / multi-walled carbon nanotube probe is immersed in the sample to perform solid phase microextraction on the target substance. The speed of the magnetic stirrer is set to 200r / min, the extraction temperature is set to 40°C, and the extraction time is set to 2min. After the extraction is completed, the probe is inserted into the channel of the dual-channel θ borosilicate glass capillary spray emitter containing 10μL methanol, and 10μL of hydroxylamine solution with a concentration of 100mmol / L is added to the other channel. The electrospray voltage is applied, and the target substance is desorbed from the probe and forms an electrospray, which undergoes an online derivatization reaction with the hydroxylamine spray. The work flow diagram of the device of the present invention is shown in Figure 2 1.2.4 Small portable mass spectrometry

[0054] The derivatized products were analyzed by a portable mass spectrometer. The analytical conditions were: positive ionization mode, spray voltage 3.5 kV, injection time 40 ms, mass scan range m / z 50–500, three parallel injections, and a distance of 1.0 cm between the tip of a dual-channel theta borosilicate glass capillary spray emitter and the inlet of the portable mass spectrometer. The analytical parameters for the four target compounds are shown in Table 1.

[0055] Table 1 Parameters of small portable mass spectrometry analysis of four weakly polar substances

[0056]

[0057] Note: *Quantitative ion

[0058] 2. Results and Discussion

[0059] 2.1 Characterization of the Dual-Channel Theta Borosilicate Glass Capillary Spray Emitter Tip

[0060] The tip size of the nanoliter extraction electrospray ionization source is directly related to the size of the microdroplets formed during the ionization process, which in turn affects the ionization efficiency. The tip of the drawn double-channel θ borosilicate glass capillary spray emitter was characterized, and the results are as follows Figure 3 As shown in the figure, the tip of the drawn dual-channel theta borosilicate glass capillary spray emitter ion source has a very regular shape, ensuring uniformity and stability in the generation of electrospray droplets from the dual channels. The tip size was measured to be 60 μm. This micrometer-sized tip facilitates the generation of smaller droplets during the electrospray process, improving ionization efficiency. It also helps accelerate the fusion of dual-channel droplets, increasing the speed of the derivatization reaction used in this study.

[0061] 2.2 Optimization of solid phase microextraction conditions

[0062] The solid-phase microextraction probe coating is polyaniline / multi-walled carbon nanotubes, whose microstructure contains a large number of three-dimensional micropores, significantly improving the specific surface area and adsorption sites; in addition, the molecular structure of polyaniline and multi-walled carbon nanotubes contains polyaniline chains and a large number of benzene rings, which can easily form π-π interactions and van der Waals forces with the target substance, thereby achieving efficient microextraction.

[0063] Solid-phase microextraction technology is based on a dynamic extraction-equilibrium process. Extraction temperature, extraction time, and magnetic rotation speed are key parameters affecting the equilibrium process. In this study, the extraction temperature was set at 30, 35, 40, and 45°C; the extraction time was set at 1, 1.5, 2, 2.5, and 3 minutes; and the rotation speed was set at 100, 200, 300, and 400 r / min. The optimization results are as follows: Figure 4 As shown. Figure 4 As can be seen from A, with the increase of temperature, the mass transfer efficiency increases, the response value of each substance gradually increases, and basically reaches stability at 40℃. Figure 4 As shown in Figure B, as the extraction time increases, the mass transfer time increases, and the response values of each substance continue to increase. When the extraction time is 2 minutes, the response values of each substance no longer increase, indicating that the mass transfer process has reached a state of equilibrium. When the extraction time reaches 3 minutes, the response values of each substance decrease slightly, which may be due to the target substance adsorbed on the extraction coating being redissolved in the sample. Figure 4 As can be seen from C, the response values of each substance show a trend of first increasing and then decreasing, reaching a maximum value at 200 r / min; after that, the response values of each substance show a downward trend. This is because the high rotation speed causes tiny bubbles to appear in the sample microenvironment, which interferes with the mass transfer process.

[0064] 2.3 Selection of desorption / spray ionization solvent

[0065] Solid-phase microextraction (SPME) combined with nanoliter extraction electrospray ionization (NEI) can simultaneously desorb and ionize target substances. Choosing the right solvent is crucial for the desorption / spray ionization process. The effects of five solvents of varying polarity—methanol, anhydrous ethanol, acetonitrile, isopropanol, and n-hexane—on the desorption / spray ionization of target substances were investigated. The results showed that solvents of varying polarity exhibited varying degrees of desorption / spray ionization for each target substance, with methanol exhibiting the strongest response. Therefore, methanol was selected as the optimal solvent for desorption / spray ionization.

[0066] 2.4 Results of small portable mass spectrometry analysis

[0067] Compared with derivatization reactions between large-volume solutions, the spray droplets produced by the dual-channel θ borosilicate glass capillary spray emitter are smaller in volume, which increases the collision between droplet molecules and shortens the mixing time; and with the electrospray desolvation process, the surface-to-volume ratio of the microdroplets is larger, the charge on the microdroplet surface is richer, and the intermolecular reaction is stronger, thereby significantly improving the reaction speed.

[0068] There are many substances that can undergo derivatization reaction with sex hormones. Among them, hydroxylamine can undergo derivatization reaction with sex hormones at room temperature, and the reaction is relatively rapid. Therefore, hydroxylamine is selected as the derivatization reagent. The derivatization reaction mechanism is as follows: Figure 5 A. Based on the optimization of the above conditions, a small portable mass spectrometer was used for analysis. The secondary mass spectra of the derivatization reaction products of each substance are shown in Figure 5 Estrone ( Figure 5 B), epitestosterone ( Figure 5 C) and testosterone ( Figure 5 D) contain a carbonyl group (C=O). After derivatization with hydroxylamine, the parent ions are m / z 286.4, 304.2 and 304.3, respectively. During the collision dissociation process, they will lose a water molecule (-H2O) to form fragment ions of m / z 268.2, 287.1 and 286.9, respectively. Figure 5 E) contains two carbonyl groups (C═O) and undergoes derivatization with hydroxylamine, forming a parent ion at m / z 317.2. During collisional dissociation, it loses two water molecules (-H₂O) to form fragment ions at m / z 300.1 and 281.7. Compared to underivatized samples, their mass spectrometric response sensitivity is improved by 3-15 times.

[0069] 2.5 Methodological Review

[0070] Methodological investigations were conducted using the experimental method for different concentrations of sex hormones. The results are shown in Table 2. Linear regression analysis, with mass concentration as the abscissa (x) and the mass spectrometric signal intensity of the derivatized product quantification ion as the ordinate (y), revealed good linear relationships for the four sex hormones within their respective linear ranges (r > 0.97). The limits of detection (LOD) and limits of quantification (LOQ) for the four sex hormones were determined using signal-to-noise ratios of 3 and 10, respectively. The limits of detection (LOD) and limits of quantification (LOQ) for the four sex hormones were 10-20 ng / mL, and 20-50 ng / mL, respectively. Toner samples that had been determined to be free of the aforementioned sex hormones were spiked with various concentrations of the aforementioned sex hormones to prepare blank matrix spiked samples for analysis. The average recoveries of the four sex hormones ranged from 84.6% to 107.8%, with relative standard deviations (RSDs) ranging from 4.1% to 11.6%.

[0071] Table 2 Methodological investigation results

[0072]

[0073] Traditional analytical methods are mainly based on high-performance liquid chromatography-tandem mass spectrometry, which requires many pre-treatment processes such as solvent extraction, centrifugation, derivatization, chromatographic separation and mass spectrometry analysis, with large consumption of organic reagents and long analysis cycles. In contrast, the analytical method established by the present invention does not require a complex sample pre-treatment process, has the advantages of low consumption of organic reagents, rapid derivatization reaction, and on-site analysis, which is more in line with the development trend of green analytical chemistry. In addition, the prepared porous polyaniline / multi-walled carbon nanotube probe is used to extract the target substance, which can achieve online and efficient enrichment of the target substance, and to a certain extent makes up for the loss of detection performance caused by the small portable mass spectrometry vacuum system.

[0074] 2.6 Actual sample analysis

[0075] The analytical method developed in this invention was applied to 14 cosmetic samples, including five children's toners, six softening lotions, and three serums. The results showed that none of the four banned sex hormones involved in this study were detected in the samples.

[0076] 3. Conclusion

[0077] A rapid on-site analysis method for four weakly polar sex hormones in cosmetics has been established using polyaniline / multi-walled carbon nanotubes as solid-phase microextraction probes, a dual-channel theta borosilicate glass capillary spray emitter as a nanoliter extraction electrospray ionization source, and a small portable mass spectrometer through rapid online derivatization reactions. This method is simple, rapid, accurate, and reliable, completing sample extraction and analysis within 3 minutes. It effectively overcomes the cumbersome and time-consuming drawbacks of traditional detection methods and provides a new approach to alternative analytical approaches.

[0078] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A rapid on-site detection device for weakly polar substances in cosmetics, characterized by: The invention comprises a solid phase microextraction probe (1), a metal wire (2), a dual-channel θ borosilicate glass capillary spray emitter (3) and a mass spectrometer (4); the dual-channel θ borosilicate glass capillary spray emitter (3) comprises two channels, a desorption solvent and a derivatization reagent are respectively arranged in the two channels; the rear ends of the solid phase microextraction probe (1) and the metal wire (2) are connected to the mass spectrometer (4), and the front ends are respectively arranged in the desorption solvent and the derivatization reagent.

2. The on-site rapid detection device for weakly polar substances in cosmetics according to claim 1, characterized in that: The coating of the solid phase microextraction probe (1) is polyaniline / multi-walled carbon nanotubes.

3. The on-site rapid detection device for weak polar substances in cosmetics according to claim 2, characterized in that: The metal wire (2) is a copper wire.

4. The on-site rapid detection device for weak polar substances in cosmetics according to claim 3, characterized in that: The mass spectrometer (1) is a Miniβ small portable mass spectrometer, and the solid phase microextraction probe (1) and the metal wire (2) are connected to a high voltage source of the Miniβ small portable mass spectrometer via a metal wire.

5. The on-site rapid detection device for weak polar substances in cosmetics according to claim 4, characterized in that: The tip size of the dual-channel θ borosilicate glass capillary spray emitter (3) is 60 μm, and the tip of the dual-channel θ borosilicate glass capillary spray emitter (3) is placed 1.0 cm from the front end of the injection port of the mass spectrometer (4); The length of the dual-channel θ borosilicate glass capillary spray emitter (3) is 6 cm, the length of the metal wire (2) and the solid phase microextraction probe (1) is 5 cm, and the depth to which the metal wire (2) and the solid phase microextraction probe (1) penetrate into the dual-channel θ borosilicate glass capillary spray emitter (3) is 4 cm.

6. A method for rapid on-site detection of weak polar substances in cosmetics using the device for rapid on-site detection of weak polar substances in cosmetics according to any one of claims 1 to 5, characterized in that: The steps include: A solid phase microextraction probe (1) is immersed in an aqueous cosmetic sample for adsorption extraction. After extraction, the probe is inserted into a channel containing a desorption solvent of a dual-channel θ borosilicate glass capillary spray emitter (3). A metal wire (2) is inserted into another channel containing a derivatization reagent. The dual-channel θ borosilicate glass capillary spray emitter (3) is placed at the front end of an injection port of a mass spectrometer (4). An ionization voltage is applied, and the two liquids form spray droplets and collide with each other to complete an online derivatization reaction. The derivatization reaction products formed are then detected by the mass spectrometer (4).

7. The on-site rapid detection method for weakly polar substances in cosmetics according to claim 6, characterized in that: The preparation method of the dual-channel θ borosilicate glass capillary spray emitter (3) comprises the following steps: using a dual-channel θ borosilicate glass capillary as a preparation material, drawing it using a microelectrode drawing instrument, setting the electrode heating temperature to 760°C, the pulling force to 0N, the heating rate to 20°C / s, the delay time to 4s, the pressure to 400kPa, and the number of cycles to 1; a complete dual-channel θ borosilicate glass capillary can be prepared into two disposable dual-channel θ borosilicate glass capillary spray emitters (3).

8. The on-site rapid detection method for weakly polar substances in cosmetics according to claim 7, characterized in that: The solid phase microextraction probe (1) is a polyaniline / multi-walled carbon nanotube extraction probe, and its preparation comprises the following steps: A stainless steel needle, cleaned with acetone, methanol, and deionized water and then air-dried, was used as a working electrode, a platinum wire as an auxiliary electrode, and an Ag / AgCl wire as a reference electrode. The electrolyte solution contained 0.5 mol / L sulfuric acid, 0.1 mol / L aniline monomer, and a 0.002% multi-walled carbon nanotube solution. The stainless steel needle was placed vertically and immersed in the electrolyte solution to a depth of 2 cm. Electrochemical deposition was performed using cyclic voltammetry with a potential range of -0.2 V to 0.9 V, a scan rate of 20 mV / s, and 15 cycles. The prepared probe was dried and cooled to room temperature for later use. The specific adsorption extraction process includes the following steps: The cosmetic samples were placed on a magnetic stirrer, and a polyaniline / multi-walled carbon nanotube probe was immersed in the sample to perform solid phase microextraction of the target substances. The magnetic stirrer speed was set at 200 r / min, the extraction temperature was 40°C, and the extraction time was 2 min. After the extraction is completed, the polyaniline / multi-walled carbon nanotube probe is inserted into the channel containing the desorption solvent of the dual-channel θ borosilicate glass capillary spray emitter (3), and the metal wire (2) is inserted into the other channel containing the derivatization reagent. The electrospray voltage is applied, and the target substance is desorbed from the probe and forms an electrospray, which undergoes an online derivatization reaction with the hydroxylamine spray.

9. The on-site rapid detection method for weakly polar substances in cosmetics according to claim 8, characterized in that: The desorption solvent was methanol, and the derivatization reagent was hydroxylamine, with a concentration of 100 mM and an addition amount of 10 μL.

10. The on-site rapid detection method for weak polar substances in cosmetics according to claim 9, characterized in that: The weakly polar substances are estrone, epitestosterone, testosterone and androstenedione; The analysis conditions of the Miniβ portable mass spectrometer are as follows: positive ionization mode, spray voltage 3.5 kV, injection time 40 ms, mass scan range m / z 50-500, and parallel injection number 3; the adduct mode, derivatization product parent ion, daughter ion and collision voltage of the four weakly polar substances are shown in Table 1: Table 1 Parameters of small portable mass spectrometry analysis of four weakly polar substances Note: *Quantitative ion.

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