A colorant rapid detection kit and a detection method thereof

Abstract

The application discloses a coloring agent rapid detection kit and a detection method thereof, relates to the field of tea sample detection, and comprises a thin layer chromatography assembly, a developing agent assembly, a sample pretreatment assembly, a sample application and development auxiliary assembly, a standard control assembly and a result interpretation assembly. The application utilizes the adsorption-desorption difference of different polar coloring agents between a thin layer chromatography stationary phase (a silica gel thin layer plate) and a mobile phase (a mixed developing agent) to realize separation and detection of the coloring agents. By being equipped with a premixed developing agent and a plurality of coloring agent standard products, the coloring agent detection requirements of different polar ranges can be adapted. The detection process only needs 30 minutes, is simple and convenient to operate, is low in cost, does not need professional instruments, solves the problems of low efficiency and high cost of the traditional detection method, is suitable for on-site rapid screening of coloring agents in tea samples, and has a wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of tea sample testing, and specifically to a rapid detection kit for colorants. Background Technology

[0002] Given the widespread use of synthetic colorants in the food and cosmetics industries and their potential safety risks, especially considering that GB 2760 Appendix B.1 and GB 31608-2023 National Food Safety Standard for Tea explicitly prohibit the use of any food additives in tea, the illegal addition of synthetic colorants to tea for profit still exists in the market. Therefore, establishing a rapid, accurate, and convenient method for detecting colorants in tea is crucial to ensuring product safety.

[0003] Currently, the detection of synthetic colorants mainly relies on laboratory techniques such as high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). While these methods offer high precision and accurate qualitative and quantitative analysis, they also have inherent limitations, including expensive equipment, complex operation, and long detection cycles, making it difficult to meet the practical needs of rapid on-site screening and grassroots testing. Therefore, developing a rapid detection kit for colorants in tea that is standardized in operation, provides stable and reliable results, has a wide range of applications, and combines qualitative and semi-quantitative functions has become an urgent technical problem to be solved. Thin-layer chromatography (TLC), as a classic separation technique, is characterized by its simple operation, fast separation speed, and low cost, and has been applied in rapid detection in many fields. Theoretically, it can be used for the separation and detection of colorants of different polarities in tea.

[0004] In view of the many shortcomings of existing synthetic colorant detection technologies, the development of a rapid colorant detection kit based on thin-layer chromatography principles, with standardized operating procedures, stable and reliable detection results, wide applicability, and the ability to simultaneously detect multiple target substances while possessing both qualitative and semi-quantitative functions, is of great practical significance and social value for improving the efficiency of grassroots food safety supervision and protecting consumer rights. This has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a rapid detection kit for colorants. Utilizing thin-layer chromatography (TLC), a standardized rapid detection kit for colorants in tea has been developed, combining qualitative and semi-quantitative functions. This addresses the technical bottlenecks of existing synthetic colorant detection technologies in tea, which are complex to operate, costly, and unable to simultaneously support rapid on-site detection and multi-component analysis. Based on the differences in the developing behavior of colorants of different polarities on TLC, this kit integrates sample pretreatment, development and separation, and result interpretation into a standardized detection kit. It enables rapid and accurate separation and detection of multiple target colorants in tea, achieving both qualitative and semi-quantitative discrimination. This invention aims to effectively lower the detection threshold through a simple and low-cost solution, meeting the urgent need for rapid on-site screening technologies in the food safety field.

[0006] The objective of this invention is achieved through the following technical solution: This colorant rapid detection kit comprises: Thin-layer chromatography assembly, comprising several silica gel thin-layer plates; The developing agent component uses a mixed developing agent composed of polar and non-polar solvents to adapt to the development of colorants with different polarity ranges. A sample pretreatment assembly includes a capped extraction tube and a stirring rod, wherein the extraction tube is used to add tea sample and extract the sample solution to be tested; The spotting and developing auxiliary components include a developing bottle for pouring developing solvent, a micro-spotting capillary for spotting the sample on the silica gel thin film plate, and tweezers for gripping the silica gel thin film plate. After the sample test liquid is spotted and developed by the spotting and developing auxiliary components, a sample strip is developed on the silica gel thin film plate. A standard control assembly includes a standard solution containing several colorants. The colorant standard solution is spotted and developed using a spotting and developing auxiliary assembly, resulting in standard bands on a silica gel thin-layer plate. By visually comparing the sample bands with the standard bands, the type of colorant can be qualitatively determined. The result interpretation component includes a standard colorimetric card, which records the color development of different concentrations of colorants after development in the corresponding developing solvent. By visually comparing the sample development results with the corresponding concentration color blocks on the standard colorimetric card, a semi-quantitative interpretation of the colorant content can be achieved.

[0007] As a further technical solution, the silicone thin-layer plate includes several silicone prefabricated plates, the silicone coating thickness of the silicone thin-layer plate is 0.2 to 0.5 mm, and the plate size is 25 mm × 75 mm.

[0008] As a further technical solution, the mixed developing agent is prepared by mixing n-butanol, anhydrous ethanol and 50% ammonia in a volume ratio of 2-8:1-3:1-5.

[0009] As a further technical solution, the mixed developing solvents are all pre-mixed and packaged, and stored in brown light-proof reagent bottles, each with a capacity of 15-20 mL, which can meet the needs of 20-30 tests.

[0010] As a further technical solution, the extraction tube has a specification of 1mL to 10mL, the stirring rod has a diameter of 1mm to 3mm, the micro-spotting capillary has a specification of 0.3μL, and the developing flask has a volume of 125mL.

[0011] As a further technical solution, the standard control component includes colorant standard solutions of tartrazine, sunset yellow, carmine, and brilliant blue, each with a concentration of 0.05 mg / mL, and water as the solvent.

[0012] As a further technical solution, the kit shell is also included. The kit shell is made of rigid paper or plastic. The inside of the kit shell is equipped with a shockproof foam liner. The thin-layer chromatography components, developing solvent components, sample pretreatment components, spotting and developing auxiliary components, standard control components and result interpretation components are placed in the grooves opened on the shockproof foam liner. The kit size is 150mm×138mm×90mm.

[0013] A rapid detection method for colorants, using the aforementioned rapid colorant detection kit, includes the following steps: S1. Sample pretreatment: Take 0.5g of representative tea sample, crush it into powder and add it to the extraction tube. Add 1mL of water, shake and stir with a stirring rod for 1min to fully soak the tea. Let it stand for 15min to obtain the sample extract. S2. Spotting: Take a silica gel thin-layer plate and lightly draw a baseline with a pencil 1.5cm away from the bottom edge of the silica gel thin-layer plate. Mark two points (1cm apart) on the baseline at equal intervals. Use a micro-spotting capillary to dip into the mixed solution of colorant standard and the supernatant of the sample extract, and spot them on the marked points in sequence. The spotting diameter should be controlled within 5mm. After the solvent has completely evaporated, the original spotting points for the sample and standard are formed. S3. Development: Pour the mixed developing solvent into the developing bottle, cover the developing bottle with the sealing cap and let it stand for 5 minutes to form saturated vapor. Use tweezers to vertically place the spotted silica gel thin-layer plate into the developing bottle, ensuring that the liquid level of the developing solvent is 0.5 cm below the baseline. After sealing, wait for 15 minutes, then immediately remove the silica gel thin-layer plate and ventilate it to dry, forming standard bands and sample bands. S4. Color Development and Interpretation: Under natural light, visually observe whether there is a colored area in the space above the sample spotting origin. If so, record the distance from the center of the standard spotting origin to the colored area and compare it with the distance from the center of the sample spotting origin to the corresponding colored area. If a stripe with the same distance and color as the standard stripe appears in the sample stripe, it is determined that the sample contains the colorant. Visually compare the colored sample stripe with the standard stripe of the corresponding colorant on the standard colorimetric card and select the color block position with the closest color depth. The concentration marked at this position is the semi-quantitative concentration range of the colorant in the sample.

[0014] As a further technical solution, steps S1 to S4 are completed within 30 minutes.

[0015] As a further technical solution, in step S4, an auxiliary incandescent light source is used to observe the silicone thin film to obtain better observation results.

[0016] The beneficial effects of this invention are as follows: 1. Fast detection speed: The entire detection process (including sample pretreatment, spotting, development, color development and result interpretation) can be completed within 30 minutes, while traditional methods such as HPLC take about 3 hours. The detection efficiency is improved by 5-7 times, which can realize rapid on-site screening. 2. Wide range of applications: This kit can be used for routine laboratory screening, and can also be extended to various point-of-care testing scenarios such as market supervision and law enforcement, on-site quality control of production enterprises, supervision of farmers' markets, and even grassroots rapid testing laboratories; 3. Wide range of applications: By being equipped with a variety of standards, it can quickly detect four relatively common colorants in tea: lemon yellow, sunset yellow, carmine, and brilliant blue, making it highly adaptable.

[0017] 4. Easy to operate: All components are standardized and packaged, the developing solvent is premixed and the spotting tools are standardized. No professional chromatography operation skills are required. Grassroots testing personnel can master the operation after simple training, which solves the problems of cumbersome operation and poor repeatability of traditional thin-layer chromatography.

[0018] 5. Low cost: The cost of a single test with the kit is only about 3 yuan, and it does not rely on large instruments, which significantly reduces the testing cost and is suitable for use by grassroots testing institutions or enterprises for daily quality control.

[0019] 6. Reliable results: The use of standardized silica gel thin-layer plates and premixed developing solvent, combined with standard colorimetric cards for interpretation, can effectively reduce operational errors and meet the qualitative requirements of rapid screening. It also has both qualitative and semi-quantitative detection functions, which helps testers to quickly estimate the content range of colorants visually. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the structure of the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of the thin-layer chromatography component (silicone thin-layer plate) in this invention.

[0022] Figure 3 This is a schematic diagram of the structure of the result interpretation component (standard colorimetric card) in this invention.

[0023] Figure 4 This is a colorimetric diagram of the colorant when colorant standards of various concentration gradients are added to a blank tea sample matrix in this invention.

[0024] Figure 5 This is a schematic diagram showing the unfolding result of a tea sample on a silicone thin-layer plate in Example 3 of the present invention.

[0025] Figure 6 This is a schematic diagram of the physical structure of the present invention.

[0026] Explanation of reference numerals in the attached figures: 1. Reagent kit casing; 2. Thin-layer chromatography assembly; 3. Developing solvent assembly; 4. Sample pretreatment assembly; 51. Developing flask; 52. Micro-spotting capillary; 53. Tweezers; 6. Standard control assembly; 7. Result interpretation assembly; 8. Shockproof foam liner; 9. Baseline A; 10. Developing solvent front B; 11. Standard band C; 12. Standard sunset yellow band C1; 13. Standard tartrazine band C2; 14. Standard carmine band C4; 15. Sample band D; 16. Sample sunset yellow band D1; 17. Sample tartrazine band D2; 18. Sample spotting origin E; 19. Standard spotting origin F; 10. Standard band G. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings: Example 1: As shown in the attached document Figures 1-3 As shown, this colorant rapid detection kit includes a thin-layer chromatography component 2, a developing solvent component 3, a sample pretreatment component 4, a spotting and developing auxiliary component, a standard control component 6, and a result interpretation component 7.

[0028] Reference Appendix Figure 2 The thin-layer chromatography assembly 2 includes several silica gel thin-layer plates. Further, each silica gel thin-layer plate includes several pre-fabricated silica gel plates, wherein the silica gel coating thickness of the thin-layer plate is 0.2–0.5 mm, and the plate size is 25 mm × 75 mm.

[0029] like Figure 1As shown, the developing solvent component 3 uses a mixed developing solvent composed of a polar solvent and a non-polar solvent mixed in a specific ratio, which can adapt to the development of colorants with different polarity ranges. Preferably, the mixed developing solvent is a mixture of n-butanol, anhydrous ethanol, and 50% ammonia in a volume ratio of 2-8:1-3:1-5. Furthermore, the mixed developing solvents are pre-mixed and packaged, and stored in brown light-proof reagent bottles to prevent solvent evaporation or light-induced deterioration. Each bottle has a capacity of 15-20 mL, which can meet the needs of 20-30 tests.

[0030] Furthermore, the sample pretreatment component 4 includes a capped plastic extraction tube and a stirring rod. The extraction tube is used to add tea sample and extract the sample test solution. Preferably, the extraction tube has a capacity of 1 mL to 10 mL, and the stirring rod has a diameter of 1 mm to 3 mm. The spotting and development auxiliary component includes a development bottle 51, a micro-spotting capillary 52, and tweezers 53. The development bottle 51 is used to pour in and contain the developing solvent. The micro-spotting capillary 52 is used for spotting on the silica gel thin-layer plate, and the tweezers 53 are used to hold the silica gel thin-layer plate. Preferably, the micro-spotting capillary 52 has a capacity of 0.3 μL, and the development bottle 51 has a volume of 125 mL. After the sample test solution is spotted and developed by the spotting and development auxiliary component, a sample band D is developed on the silica gel thin-layer plate, as shown below. Figure 5 As shown.

[0031] The standard control component 6 includes standard solutions containing several colorants. Preferably, the colorant standard solutions included in the standard control component 6 are tartrazine, sunset yellow, carmine, and brilliant blue standard solutions, each with a concentration of 0.05 mg / mL, and the solvent is water. After the colorant standard solutions are spotted and developed using the spotting and developing auxiliary components, standard bands C are developed on a silica gel thin-layer plate, as shown in the example. Figure 5 As shown, the type of colorant can be qualitatively determined by visually comparing sample band D with standard band C.

[0032] Further, see attached document. Figure 3 The result interpretation component 7 includes a standard colorimetric card, which records the color development of different concentrations (0-200 mg / kg) of colorants (tartrazine, sunset yellow, carmine, brilliant blue) in the corresponding developing solvent. By visually comparing the sample development results with the corresponding concentration color blocks on the standard colorimetric card, a semi-quantitative interpretation of the colorant content can be achieved.

[0033] Furthermore, such as Figure 1As shown, the kit also includes a kit shell 1, which is made of rigid paper or plastic. Inside the kit shell 1, there is a shockproof foam liner 8. Each component (thin-layer chromatography component 2, developing solvent component 3, sample pretreatment component 4, spotting and development auxiliary component, standard control component 6, and result interpretation component 7) is placed in the grooves opened on the shockproof foam liner 8 to ensure that each component is not damaged during transportation. The kit size is 150mm×138mm×90mm, which is easy to carry.

[0034] Example 2: A rapid detection method for colorants, using the colorant rapid detection kit from Example 1, includes the following steps: S1. Sample pretreatment: Take 0.5g of representative tea sample, crush it into powder and add it to the extraction tube. Add 1mL of water and stir with a stirring rod for 1min to fully soak the tea. Let it stand for 15min to obtain the sample extract. S2. Spotting: Take a silica gel thin-layer plate and lightly draw a baseline A with a pencil 1.5 cm from the bottom edge of the plate. Mark two points (1 cm apart) at equal intervals on baseline A. Use a micro-spotting capillary 52 to pick up the mixed solution of colorant standard and the sample test solution, respectively, and spot them onto the marked points in sequence. The spotting diameter should be controlled within 5 mm. After the solvent has completely evaporated, the sample spotting origin E and the standard spotting origin F are formed. Figure 5 As shown, since the mixed solution of colorant standards has been developed with the developing solvent after the test, the origin point F of the standard spotting is at... Figure 5 It is almost invisible in the middle. Furthermore, Figure 5 The middle propellant front B indicates the position of the frontmost point of the upward diffusion of the propellant.

[0035] S3. Development: Pour the mixed developing solvent into the developing bottle 51, cover the developing bottle 51 with the sealing cap and let it stand for 5 minutes to form saturated vapor. Use tweezers 53 to vertically place the spotted silica gel thin-layer plate into the developing bottle 51, ensuring that the liquid level of the developing solvent is 0.5 cm below the baseline A. After sealing, wait for 15 minutes, then immediately remove the silica gel thin-layer plate and ventilate it to dry, forming the standard band C and the sample band D. S4. Color Development and Interpretation: Under natural light, visually observe whether there is a colored area in the space above the sample spot origin E (i.e., sample band D) (e.g., whether there is a colored area). Figure 5 (Sample sunset yellow band D1, sample lemon yellow band D2), if present, record the distance from the center of the standard sample spot origin F to the coloring area (e.g., Figure 5The distances of the standard sunset yellow band (C1), standard bright blue band (C2), standard lemon yellow band (C3), and standard carmine band (C4) in the sample are compared with the distances from the center of the sample spot origin E to the corresponding colored areas. If a band (colored areas D1 and D2) appears in sample band D with the same distance and color as the standard band C, then it is determined that the sample contains that colorant (i.e., qualitative judgment is achieved). Then, the colored sample band D is visually compared with the standard band G of the corresponding colorant on the standard colorimetric card. The position of the color block with the closest color depth is selected. The concentration marked at this position is the semi-quantitative concentration range of the colorant in the sample, achieving semi-quantitative interpretation.

[0036] Furthermore, steps S1 to S4 are completed within 30 minutes, while traditional methods such as HPLC require about 3 hours, improving detection efficiency by 5-7 times and enabling rapid on-site screening.

[0037] Preferably, in step S4, a back incandescent light source is used to observe the silicone thin film to obtain better observation results.

[0038] Example 3: Mixed standard samples containing Sunset Yellow, Tartrazine, Carmine, and Brilliant Blue were prepared and tested according to the steps described in Example 2. Figure 4 As shown, the results indicate that the four colorants were effectively separated on the thin-layer plate, with clear spots without tailing, consistent with the standard control card, and the repeatability of parallel sample test results was good. Furthermore, from... Figure 4 It can be seen that the visual detection limit of tartrazine in the extract is ≥10 mg / kg, while the visual detection limits of sunset yellow, carmine, and brilliant blue are all below 10 mg / kg. The visual detection limits of all four colorants meet the range of ≥10 mg / kg.

[0039] Verification Case: Adding 10 mg / kg Sunset Yellow and 50 mg / kg Tartrazine (concentrations commonly found in commercially available teas with excessive levels of colorants) to a tea sample that did not contain any colorants yielded the following results: Figure 5 As shown. Figure 5 Comparing sample band D with standard band C (qualitative band), Sunset Yellow (sample Sunset Yellow band D1) and Tartrazine (sample Tartrazine band D2) were found in the sample, but no Brilliant Blue or Carmine bands were found, indicating that Sunset Yellow and Tartrazine exceeded the standards in this sample. Comparing sample band D with standard band G on the standard colorimetric card (result interpretation component 7), the total coloring doses of Sunset Yellow and Tartrazine in tea were found to be approximately 10 mg / kg and 50 mg / kg, respectively, which is consistent with the added dosage and meets the requirements for semi-quantitative detection.

[0040] The working process of this invention: Interpretation principle: Observe whether there is a colored band in the space above the sample point. If so, visually compare the colored band with the standard band of the corresponding colorant on the colorimetric card. Select the color patch with the closest color depth; the concentration indicated by this patch is the semi-quantitative concentration range of the colorant in the sample. From Figure 4 It can be seen that the visual detection limit of tartrazine in the extract is ≥10 mg / kg, while the visual detection limits of sunset yellow, carmine, and brilliant blue are all below 10 mg / kg. The visual detection limits of all four colorants meet the range of ≥10 mg / kg.

[0041] The core design principle of this invention is as follows: colorant molecules of different polarities exhibit varying adsorption forces with the thin-layer chromatography stationary phase (silica gel), and also differ in their solubility forces with the mobile phase (developing solvent). As the developing solvent diffuses along the stationary phase on the thin-layer plate, the colorant molecules undergo repeated adsorption-desorption processes between the stationary and mobile phases. Stronger polarity colorant molecules exhibit stronger adsorption to the polar silica stationary phase, resulting in lower solubility in the mobile phase, thus leading to slower development speed and smaller specific migration values. Conversely, weaker polarity colorant molecules exhibit weaker adsorption to the stationary phase, resulting in higher solubility in the mobile phase, faster development speed, and larger specific migration values. By selecting a suitable developing solvent system, colorants of different polarities in the sample can be effectively separated on the thin-layer plate. Qualitative and semi-quantitative detection of the colorants can then be achieved by comparing their Rf values ​​and colors with standards, as well as by comparing them with colorimetric cards of different concentrations.

[0042] Furthermore, existing TLC-based pigment detection methods all employ organic solvent extraction (such as acetone, ethanol-ammonia solution, etc.), which involves cumbersome processing steps and poses risks associated with organic solvents. In contrast, this invention, targeting tea matrix, utilizes the water-soluble nature of synthetic colorants, employing only pure water for direct extraction. This method is the simplest, requires no organic solvents, and provides extraction results sufficient for visual interpretation, demonstrating the unique value of tea matrix specificity.

[0043] It is understood that, for those skilled in the art, any equivalent substitutions or modifications to the technical solutions and inventive concepts of this invention should fall within the scope of protection of the appended claims.

Claims

1. A rapid detection kit for colorants, characterized in that, include: Thin-layer chromatography assembly (2), comprising several silica gel thin-layer plates; The developing agent component (3) uses a mixed developing agent composed of polar solvent and non-polar solvent to adapt to the development of colorants with different polarity ranges; The sample pretreatment component (4) includes an extraction tube with a cap and a stirring rod, wherein the extraction tube is used to add tea sample and extract the sample test liquid; The spotting and development auxiliary components include a development bottle (51) for pouring the developing solvent, a micro-spotting capillary (52) for spotting the sample on the silica gel thin film plate, and tweezers (53) for gripping the silica gel thin film plate. After the sample test liquid is spotted and developed by the spotting and development auxiliary components, a sample strip (D) is developed on the silica gel thin film plate. The standard control component (6) includes a standard solution containing several colorants. After the colorant standard solution is spotted and developed by the spotting and development auxiliary component, a standard strip (C) is developed on the silica gel thin film plate. By visually comparing the sample strip (D) with the standard strip (C), the qualitative judgment of the type of colorant can be achieved. The result interpretation component (7) includes a standard colorimetric card, which records the color development of different concentrations of colorants after development in the corresponding developing solvent. By visually comparing the sample development results with the corresponding concentration color blocks on the standard colorimetric card, a semi-quantitative interpretation of the colorant content can be achieved.

2. The colorant rapid detection kit according to claim 1, characterized in that: The silicone thin-layer plate comprises several silicone prefabricated plates, the silicone coating thickness of the silicone thin-layer plate is 0.2-0.5mm, and the plate size is 25mm×75mm.

3. The colorant rapid detection kit according to claim 1, characterized in that: The mixed developing agent is prepared by mixing n-butanol, anhydrous ethanol and 50% ammonia in a volume ratio of 2-8:1-3:1-5.

4. The colorant rapid detection kit according to claim 1, characterized in that: The mixed developing solvents are all premixed and packaged, and stored in brown light-proof reagent bottles, each with a capacity of 15-20 mL, which is sufficient for 20-30 tests.

5. The colorant rapid detection kit according to claim 1, characterized in that: The extraction tube has a specification of 1mL to 10mL, the stirring rod has a diameter of 1mm to 3mm, the micro-spotting capillary (52) has a specification of 0.3μL, and the developing flask (51) has a volume of 125mL.

6. The colorant rapid detection kit according to claim 1, characterized in that: The standard control component (6) contains colorant standard solutions of tartrazine, sunset yellow, carmine, and brilliant blue, each with a concentration of 0.05 mg / mL, and water as the solvent.

7. The colorant rapid detection kit according to claim 1, characterized in that: It also includes a reagent kit shell (1), which is made of hard paper or plastic. The inside of the reagent kit shell (1) is provided with a shockproof foam liner (8). The thin layer chromatography component (2), the developing solvent component (3), the sample pretreatment component (4), the spotting and developing auxiliary component, the standard control component (6) and the result interpretation component (7) are placed in the grooves opened on the shockproof foam liner (8). The size of the reagent kit is 150mm×138mm×90mm.

8. A rapid detection method for colorants, using a rapid colorant detection kit as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Sample pretreatment: Take 0.5g of representative tea sample, crush it into powder and add it to the extraction tube. Add 1mL of water and stir with a stirring rod for 1min to fully soak the tea. Let it stand for 15min to obtain the sample extract. S2. Spotting: Take a silica gel thin-layer plate and lightly draw a baseline (A) with a pencil 1.5 cm from the bottom edge. Mark two points at equal intervals on the baseline (A). Use a micro-spotting capillary (52) to dip into the mixed solution of the colorant standard and the supernatant of the sample extract, and spot the samples onto the marked points in sequence. The spotting diameter should be controlled within 5 mm. After the solvent has completely evaporated, the sample spotting origin (E) and the standard spotting origin (F) are formed. S3. Development: Pour the mixed developing solvent into the developing bottle (51), cover the developing bottle (51) with the sealing cap and let it stand for 5 minutes to form saturated vapor. Use tweezers (53) to vertically place the spotted silica gel thin-layer plate into the developing bottle (51), ensuring that the liquid level of the developing solvent is 0.5 cm below the baseline (A). After sealing, wait for 15 minutes, then immediately remove the silica gel thin-layer plate, ventilate and dry it to form the standard strip (C) and the sample strip (D). S4. Color Development and Interpretation: Under natural light, visually observe whether there is a colored area in the space above the sample spotting origin (E). If so, record the distance from the center of the standard spotting origin (F) to the colored area and compare it with the distance from the center of the sample spotting origin (E) to the corresponding colored area. If a band appears in the sample band (D) with the same distance and color as the standard band (C), it is determined that the sample contains the colorant. Visually compare the colored sample band (D) with the standard band (G) of the corresponding colorant on the standard colorimetric card and select the color block position with the closest color depth. The concentration marked at this position is the semi-quantitative concentration range of the colorant in the sample.

9. The rapid detection method for colorants according to claim 8, characterized in that: Steps S1 to S4 are completed within 30 minutes.

10. The rapid detection method for colorants according to claim 8, characterized in that: In step S4, a back incandescent light source is used to observe the silicone thin film to obtain better observation results.

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