Rapid colorimetric detection method for glyphosate by one-pot method

Abstract

The invention belongs to the technical field of analytical chemistry detection, and particularly relates to a one-pot glyphosate rapid colorimetric detection method. According to the method, a glyphosate colorimetric detection system is constructed based on the mixed solution A, B, C, D and E, and rapid qualitative judgment and quantitative analysis of glyphosate are realized according to the change of colorimetric signals of the solution system before and after the glyphosate is added. The method has the advantages of simple operation, high sensitivity, fast response and low cost in glyphosate detection, and can realize fast and specific detection of glyphosate. The invention not only constructs a one-pot glyphosate rapid colorimetric detection method, but also provides a colorimetric detection reagent reliability and effectiveness discrimination method and standard, and provides technical support for rapid detection and identification of glyphosate in environment and food.

Description

Technical Field

[0001] The invention belongs to the technical field of analytical chemistry detection, and particularly relates to a one-pot rapid colorimetric detection method for glyphosate. Background Art

[0002] As one of the most widely used herbicides worldwide, glyphosate has become an indispensable tool in modern agricultural production. However, with the increasing use of glyphosate, its potential risks to the environment and human health have gradually attracted widespread attention. Long-term exposure to glyphosate may pose potential hazards to human health, such as endocrine disruption, immune system damage, and is even believed to be associated with the development of cancer. To ensure ecological safety and public health, timely and accurate monitoring of glyphosate residues has become extremely important. Therefore, the development of efficient, rapid, and low-cost glyphosate detection methods has become a critical need in the fields of food safety and environmental protection.

[0003] Currently, traditional glyphosate detection methods primarily rely on techniques such as gas chromatography (GC), liquid chromatography (HPLC), and high-performance liquid chromatography-mass spectrometry (LC-MS). While these methods offer high accuracy, they are cumbersome, costly, and time-consuming, making them unsuitable for large-scale rapid detection. While immunoassays (such as enzyme-linked immunosorbent assays) offer a relatively simple detection method, they still have limitations in their specific identification of glyphosate. Colorimetry, with its advantages of rapid response, ease of operation, and visualization, is gradually becoming an emerging alternative to traditional methods. Currently, spectroscopic glyphosate detection methods using functional nanomaterials exist, such as fluorescence detection using carbon dots as photosensitizers and a blue fluorescent internal standard, colorimetric detection based on infrared-enhanced defect-molybdenum-phosphorus-doped ferroferric oxide nanozymes, colorimetric methods based on glyphosate inhibiting copper ion peroxidase activity, and colorimetric methods based on inhibiting the peroxidase activity of nanoferroferric oxide modified with heptanoic acid / Prussian blue. Although these methods can detect and analyze glyphosate, the preparation process of nanomaterials is cumbersome, expensive, and requires high technical skills, making them difficult to mass-produce and limited to laboratory research.

[0004] Therefore, there is an urgent need to develop a simple, rapid and low-cost colorimetric detection method for glyphosate, which is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] In light of this, the present invention aims to provide a one-pot rapid colorimetric detection method for glyphosate. This method enables precise quantitative analysis and qualitative identification of glyphosate, providing an efficient and feasible solution for establishing a glyphosate-specific detection system and method.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The one-pot rapid colorimetric detection method for glyphosate comprises the following steps:

[0008] (1) Preparation of solution

[0009] Prepare solutions A, B, C, D, and E for the colorimetric system;

[0010] (2) Incubation reaction

[0011] Take appropriate amounts of the prepared solutions A, B, and C respectively and add them to a centrifuge tube, mix them, add glyphosate, and leave them for a certain time t1;

[0012] (3) Colorimetric determination

[0013] Add appropriate amount of prepared solution D and E to the above centrifuge tube, mix for a certain time t2, and measure by UV-visible spectrometer;

[0014] (4) Result analysis

[0015] By comparing the colorimetric signals before and after the addition of glyphosate, qualitative discrimination and quantitative analysis of glyphosate can be achieved based on the signal changes.

[0016] Preferably, the detection method further comprises: a method and standard for determining the reliability and effectiveness of the colorimetric reagent, wherein the determination method is the naked eye method and the determination standard is whether a precipitate is generated; specifically, the result determination standard is as follows:

[0017]

[0018] / indicates no precipitation was observed in the purple solution

[0019] √ indicates that a precipitate was observed in the purple solution

[0020] When the result is / , it indicates that the colorimetric reagent cannot be used for glyphosate detection; when the result is √, it indicates that the colorimetric reagent can be used for glyphosate detection.

[0021] Furthermore, reagent A is one or more combinations of sodium nitrite, potassium nitrite, and nitrosamine; reagent B is one or more combinations of sodium bromide, potassium bromide, sodium chloride, and potassium chloride; reagent C is one or more combinations of formic acid, acetic acid, sulfuric acid, and nitric acid; reagent D is one or more combinations of p-aminobenzenesulfonic acid and p-aminobenzenesulfonamide; and reagent E is one or more combinations of N-1-naphthylethylenediamine and α-naphthylamine.

[0022] Preferably, in step (2), the mixed concentration of solution A is 0.01-50 mM, the mixed concentration of solution B is 0.02-200 mM, and the mixed concentration of solution C is 0.1-1000 mM.

[0023] Preferably, in step (2), the solution mixing time t1 is 1-40 min.

[0024] Preferably, in step (2), the molar ratio of solution A, solution B and solution C is 1:10:30-1:40:60.

[0025] Preferably, in step (3), the mixed concentration of solution D is 0.02-50 mM, and the mixed concentration of solution E is 0.05-10 mM.

[0026] Preferably, in step (3), the solution mixing time t2 is 1-180s.

[0027] Preferably, in step (3), the molar ratio of solution A, solution D and solution E is 1:0.5:10-1:10:50.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The one-pot rapid colorimetric detection system for glyphosate provided by the present invention has the advantages of simple preparation, high stability, and rapid response.

[0030] (2) The one-pot rapid colorimetric detection method for glyphosate provided by the present invention has simple steps, visualized results, and intuitive analysis results.

[0031] (3) The colorimetric detection method for glyphosate provided by the present invention is simple, rapid, sensitive, and low-cost, and can realize the qualitative and quantitative detection of glyphosate, providing technical support for the rapid detection and identification of glyphosate in the environment and food. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0033] Figure 1 It is the UV-visible spectrum of the sodium nitrite, sulfuric acid and glyphosate system of potassium bromide with different concentrations in the present invention.

[0034] Figure 2 It is the UV-visible spectrum of the sodium nitrite, potassium bromide and glyphosate system with different concentrations of sulfuric acid of the present invention.

[0035] Figure 3 It is the ultraviolet-visible spectrum diagram of the solution system of the present invention at different times.

[0036] Figure 4It is the ultraviolet-visible spectrum diagram of the colorimetric solution system of the present invention.

[0037] Figure 5 It is a UV-visible spectrum kinetic diagram of the potassium bromide colorimetric system of the present invention.

[0038] Figure 6 It is a UV-visible spectrum kinetic diagram of the sulfuric acid colorimetric system of the present invention.

[0039] Figure 7 It is the ultraviolet-visible spectrum of the glyphosate solution system of the present invention.

[0040] Figure 8 It is an image diagram of a different color system. DETAILED DESCRIPTION

[0041] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0042] The term "embodiment" is used herein specifically to describe any embodiment as "exemplary," and should not be construed as superior or preferable to other embodiments. Performance indicators in the embodiments of this application were tested using conventional testing methods in the art, unless otherwise specified. It should be understood that the terms used in this application are intended solely to describe specific implementations and are not intended to limit the disclosure herein.

[0043] Unless otherwise specified, the technical and scientific terms used herein have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs; other experimental methods and technical means not specifically specified in this application refer to experimental methods and technical means commonly used by ordinary technicians in this field.

[0044] In the description of the present invention, it should be understood that the terms "middle", "upper", "lower", "ascend", "descend", "vertical", "surface", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0045] In order to better illustrate the content of this application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that this application can be implemented without certain specific details. In the examples, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the main purpose of this application.

[0046] Under the premise of no conflict, the technical features disclosed in the embodiments of this application can be combined arbitrarily, and the resulting technical solutions belong to the contents disclosed in the embodiments of this application.

[0047] The invention discloses a one-pot method for rapid colorimetric detection of glyphosate.

[0048] For a better understanding of the present invention, the present invention is further specifically described below through the following examples, but it should not be understood as limiting the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above invention content are also considered to fall within the scope of protection of the present invention.

[0049] Example 1 UV-visible spectra of sodium nitrite, sulfuric acid, and glyphosate systems with different concentrations of potassium bromide

[0050] Take sodium nitrite and glyphosate solutions respectively, then add potassium bromide and sulfuric acid. After mixing, the concentrations of each substance are 5mM, 0.15mM, 0.001mM, and 300mM respectively. Let it stand at room temperature for 2 minutes, and measure the UV-visible absorption spectrum of the system, such as Figure 1 As shown in a.

[0051] Take sodium nitrite and glyphosate solutions respectively, then add potassium bromide and sulfuric acid. After mixing, the concentrations of each substance are 5mM, 0.15mM, 100mM, and 300mM respectively. Let it stand at room temperature for 2 minutes, and measure the UV-visible absorption spectrum of the system. Figure 1 As shown in b.

[0052] As can be seen from the figure, under low concentration potassium bromide conditions, no obvious absorption peak was observed at 238nm ( Figure 1 a); When the potassium bromide concentration was increased to 100 mM, a new UV-visible absorption peak was observed at 238 nm in the solution system (the appearance of this peak can be used for qualitative identification of glyphosate), and the absorption peak intensity was strong ( Figure 1 b).

[0053] The results showed that potassium bromide promoted the reaction between sodium nitrite and glyphosate, producing a new product and increasing the reaction conversion rate. This product had an absorption peak at 238. Therefore, in the colorimetric system, increasing the potassium bromide concentration is beneficial to enhancing the performance of the detection system.

[0054] Example 2 UV-visible spectra of sodium nitrite, potassium bromide, and glyphosate systems with different concentrations of sulfuric acid

[0055] Take sodium nitrite and glyphosate solutions respectively, then add potassium bromide and sulfuric acid. After mixing, the concentrations of each substance are 5mM, 0.15mM, 100mM, and 100mM respectively. Let it stand at room temperature for 12 minutes, and measure the UV-visible absorption spectrum of the system. Figure 2 As shown in a.

[0056] Take sodium nitrite and glyphosate solution respectively, then add potassium bromide and sulfuric acid. After mixing, the concentrations of each substance are 5mM, 0.15mM, 100mM, and 300mM respectively. Let it stand at room temperature for 12 minutes, and measure the UV-visible absorption spectrum of the system. Figure 2 As shown in b.

[0057] As can be seen from the figure, under the condition of 100mM sulfuric acid concentration, the reaction system has a significant absorption peak at 238nm ( Figure 2 a), when the sulfuric acid concentration increased to 300 mM, the absorption peak at 238 nm further increased significantly ( Figure 2 b).

[0058] The results showed that sulfuric acid can promote the reaction of sodium nitrite and glyphosate and increase the conversion rate of the reaction products. Therefore, in the colorimetric system, increasing the sulfuric acid concentration is beneficial to enhance the detection performance of the system.

[0059] Example 3 UV-visible spectra of solution systems at different times

[0060] Take sodium nitrite and glyphosate solution respectively, then add potassium bromide and sulfuric acid solution. After mixing, the concentrations of each substance in the system are 5mM, 0.15mM, 100mM, and 300mM respectively. Let it stand at room temperature and measure the UV-visible absorption spectrum of the system at different times, such as Figure 3 shown.

[0061] Figure 3 This is the optimized reaction kinetics time curve for sodium nitrite and glyphosate solution. As can be seen from the figure, under the concentration conditions of this system, the absorption peak of the reaction system at 238nm gradually increases with time. The reaction is fastest and the peak change is the fastest between 0 and 2 minutes, then gradually slows down. An inflection point appears at 6 minutes, and the peak intensity no longer changes significantly at 10 minutes, indicating that the reaction system has reached a steady state.

[0062] Example 4 Colorimetric Solution System UV-Vis Spectrum

[0063] Sodium nitrite, potassium bromide, and sulfuric acid were taken separately and allowed to stand at room temperature for 15 minutes. Then, p-aminobenzenesulfonic acid and N-1-naphthylethylenediamine solution were added. The final concentrations of A, B, C, D, and E in the system were 5mM, 100mM, 300mM, 4mM, and 4mM, respectively. After mixing, the UV-visible absorption spectrum of the system was measured. Figure 4 shown.

[0064] from Figure 4 It can be seen that when p-aminobenzenesulfonic acid and N-1-naphthylethylenediamine solution are added to the above-mentioned sodium nitrite, potassium bromide and sulfuric acid system, a strong absorption peak appears at about 516nm in the colorimetric system (this peak can be used for quantitative analysis of glyphosate), and the absorption peak intensity is 1.04. This peak is used as the colorimetric detection benchmark, and its changes can be used for qualitative discrimination and quantitative detection of glyphosate.

[0065] Example 5 Effect of Potassium Bromide on the Dynamics of UV-Vis Spectra of Colorimetric Systems

[0066] Sodium nitrite, p-aminobenzenesulfonic acid, and N-1-naphthylethylenediamine solutions were taken separately, and then potassium bromide was added to the above system. The final concentrations of various substances after mixing were 4mM, 4mM, 3mM, and 80mM, respectively. The UV-visible absorption spectra of the colorimetric system were measured at different times of 1min, 3min, 5min, 7min, and 9min, as shown in FIG. Figure 5 shown.

[0067] from Figure 5 It can be seen that when potassium bromide is added to the sodium nitrite, p-aminobenzenesulfonic acid, and N-1-naphthylethylenediamine solution system, the colorimetric detection peak decreases with time, indicating that the potassium bromide system is a time-dynamic decay process. To ensure the best detection performance, the detection time is preferably 1 minute.

[0068] Example 6 Effect of sulfuric acid on the UV-visible spectral dynamics of the color system

[0069] Sodium nitrite, p-aminobenzenesulfonic acid, and N-1-naphthylethylenediamine solutions were taken separately, and then sulfuric acid was added to the above system. The final concentrations of various substances after mixing were 4mM, 4mM, 3mM, and 240mM, respectively. The UV-visible absorption spectra of the colorimetric system were measured at different times of 1min, 3min, 5min, 7min, and 9min, as shown in FIG. Figure 6 shown.

[0070] from Figure 6 It can be seen that when sulfuric acid is added to the sodium nitrite, p-aminobenzenesulfonic acid, and N-1-naphthylethylenediamine solution system, the colorimetric detection peak also decreases with time, indicating that the acid system also undergoes a time-dynamic decay process. To ensure optimal detection performance, the detection time is preferably 1 min.

[0071] Example 7 UV-visible spectrum of glyphosate solution system

[0072] Sodium nitrite, potassium bromide, sulfuric acid, and glyphosate solutions were added to centrifuge tubes respectively, allowed to stand at room temperature for 15 minutes, and then p-aminobenzenesulfonic acid and N-1-naphthylethylenediamine solutions were added. The final concentrations of sodium nitrite, potassium bromide, sulfuric acid, p-aminobenzenesulfonic acid, and N-1-naphthylethylenediamine in the system were 5mM, 100mM, 300mM, 0.15mM, 4mM, and 4mM, respectively. After mixing, the UV-visible absorption spectrum of the system was measured.

[0073] like Figure 7 As shown, glyphosate was added to the sodium nitrite, potassium bromide, and sulfuric acid system, and then p-aminobenzenesulfonic acid and N-1-naphthylethylenediamine solution were added. Compared with Example 4, the colorimetric system showed a strong absorption peak intensity at about 516 nm, which decreased significantly to 0.22, and the absorption peak intensity change value was 0.82. Based on this peak intensity change, quantitative detection of glyphosate can be achieved.

[0074] Example 8 Method for Determining the Validity and Reliability of a Colorimetric Solution System

[0075] This colorimetric system uses colorimetric signals to detect glyphosate. To ensure the reliability of the colorimetric reagents and the validity of the results, it can be used for glyphosate analysis. Table 1 lists the methods and criteria for determining the reliability and validity of the colorimetric reagents. The determination method is the naked eye method, and the criterion is the presence of precipitation.

[0076] Table 1 Result judgment criteria

[0077]

[0078]

[0079] / indicates no precipitation was observed in the purple solution

[0080] √ indicates that a precipitate was observed in the purple solution

[0081] Table 1 shows the discrimination method and criteria. When the result is / , it indicates that the colorimetric reagent cannot be used for glyphosate detection; when the result is √, it indicates that the colorimetric reagent can be used for glyphosate detection.

[0082] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A one-pot rapid colorimetric detection method for glyphosate, characterized in that: The steps include: (1) Preparation of solution Prepare solutions A, B, C, D, and E for the colorimetric system; (2) Incubation reaction Add appropriate amounts of the prepared solutions A, B, and C to a centrifuge tube, mix, add glyphosate, and allow to stand for a certain time t1; (3) Colorimetric determination Add appropriate amounts of the prepared solutions D and E to the centrifuge tube after placement in step (2), mix for a certain time t2, and measure; (4) Result analysis By comparing the colorimetric signals before and after the addition of glyphosate, qualitative discrimination and quantitative analysis of glyphosate can be achieved based on the signal changes.

2. The one-pot rapid colorimetric detection method for glyphosate according to claim 1, wherein: Also includes: The reliability and effectiveness of colorimetric reagents are determined by naked eye method and the criterion is whether a precipitate is formed. Specifically, the results are determined by the following criteria: / indicates no precipitation was observed in the purple solution √ indicates that a precipitate was observed in the purple solution When the result is / , it indicates that the colorimetric reagent cannot be used for glyphosate detection; when the result is √, it indicates that the colorimetric reagent can be used for glyphosate detection.

3. The one-pot rapid colorimetric detection method for glyphosate according to claim 1, wherein: Reagent A is one or more combinations of sodium nitrite, potassium nitrite, and nitrosamine; Reagent B is one or more combinations of sodium bromide, potassium bromide, sodium chloride, and potassium chloride; Reagent C is one or more combinations of formic acid, acetic acid, sulfuric acid, and nitric acid; Reagent D is one or more combinations of p-aminobenzenesulfonic acid and p-aminobenzenesulfonamide; Reagent E is one or more combinations of N-1-naphthylethylenediamine and α-naphthylamine.

4. The one-pot rapid colorimetric detection method for glyphosate according to claim 1, wherein: In step (2), the mixed concentration of solution A is 0.01-50 mM, the mixed concentration of solution B is 0.02-200 mM, and the mixed concentration of solution C is 0.1-1000 mM.

5. The one-pot rapid colorimetric detection method for glyphosate according to claim 1, wherein: In step (2), the solution mixing time t1 is 1-40 min.

6. The one-pot rapid colorimetric detection method for glyphosate according to claim 1, wherein: In step (2), the molar ratio of solution A, solution B and solution C is 1:10:30-1:40:

60.

7. The one-pot rapid colorimetric detection method for glyphosate according to claim 1, wherein: In step (3), the mixed concentration of solution D is 0.02-50 mM, and the mixed concentration of solution E is 0.05-10 mM.

8. The one-pot rapid colorimetric detection method for glyphosate according to claim 1, wherein: In step (3), the solution mixing time t2 is 1-180s.

9. The one-pot rapid colorimetric detection method for glyphosate according to claim 1, wherein: In step (3), the molar ratio of solution A, solution D and solution E is 1:0.5:10-1:10:50.

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