Kit for detecting paraoxon organophosphorus pesticide in real time

Abstract

The invention discloses a kit for detecting paraoxon and phosphorus organophosphorus pesticides in real time, and belongs to the technical field of pesticide detection. The invention provides a high-selectivity kit for real-time detection of paraoxon organophosphorus pesticides, the kit comprises the following components: a methanol solution, a cerium dioxide nano dispersion liquid and a sodium hydroxide solution, and during use, the paraoxon organophosphorus pesticide residue is detected through color change. The high-selectivity kit for real-time detection of the oxyphosphate organophosphorus pesticide can be used for on-site handheld detection of the oxyphosphate organophosphorus pesticide, and has the advantages of low cost, simplicity in manufacturing, simplicity and convenience in operation, high selectivity and the like.

Description

Technical Field

[0001] The present invention relates to a kit for real-time detection of paraoxon organophosphorus pesticides, belonging to the technical field of pesticide detection. Background Art

[0002] Agriculture is the foundation of China's national economy and the primary industry of China's development. In agricultural production, many producers compound organophosphorus pesticides (OPs) when preventing and controlling pests. The extensive use of pesticides will lead to excessive residues of OPs in fruits and vegetables, and these pesticides will cause harm to organisms. Therefore, the development of rapid detection technology for OPs is of great significance for protecting human health and the environment.

[0003] At present, there are various analytical methods for detecting organophosphorus pesticides, including high-performance liquid chromatography, gas chromatography, gas chromatography-mass spectrometry, etc. Although these methods can achieve sensitive detection of OPs, these detection methods usually require complex sample pretreatment and professional technical personnel, the equipment is expensive, the detection speed is slow, and real-time detection cannot be achieved. Summary of the Invention

[0004] In order to solve the problems existing in the existing detection of organophosphorus pesticides, the present invention provides a kit for real-time detection of paraoxon organophosphorus pesticides, and the kit includes: methanol solution, cerium dioxide nano-dispersion and sodium hydroxide solution.

[0005] Preferably, the methanol solution is obtained by mixing anhydrous methanol and water in a volume ratio of 1:1.

[0006] Preferably, the concentration of the sodium hydroxide solution is 3.875 - 7.75 mol / L.

[0007] Preferably, the preparation method of the cerium dioxide nano-dispersion is as follows:

[0008] (1) Dissolve NaOH solid and Ce(NO3)3·6H2O solid respectively to obtain NaOH solution and Ce(NO3)3 solution, and mix the NaOH solution and Ce(NO3)3 solution evenly under stirring to obtain a mixed solution.

[0009] (2) Dry the mixed solution, dry and grind the solid after centrifugal washing to obtain CeO2 powder.

[0010] (3) Disperse the CeO2 powder into deionized water to obtain the cerium dioxide nano-dispersion.

[0011] Preferably, in step (1), the mass ratio of NaOH solid to Ce(NO3)3·6H2O solid is 1:1 - 1.2:1.

[0012] Preferably, in step (2), the drying temperature is 90-110°C and the drying time is 15-25h.

[0013] Preferably, the concentration of the cerium dioxide nano-dispersion is 1.8-2.0 mg / mL.

[0014] Preferably, the usage method of the kit is as follows:

[0015] (1) Take the sample to be detected, add a methanol solution 5 times the volume of the sample, stir well, then take out the sample to be detected and retain the liquid.

[0016] (2) Add an equal volume of cerium dioxide nano-dispersion and an equal volume of sodium hydroxide solution to the liquid retained in step (1) (if 5 mL of liquid was retained in step (1), then add 5 mL of cerium dioxide nano-dispersion and 5 mL of sodium hydroxide), mix evenly, observe the color change. When the solution is yellow, there is parathion-type organophosphorus pesticide residue in the sample; when there is no change in the solution, there is no parathion-type organophosphorus pesticide residue in the sample.

[0017] Technical effects of the present invention:

[0018] The kit for real-time detection of parathion-type organophosphorus pesticides prepared by the present invention has the advantages of high selectivity, no need for sample pretreatment, low cost, simple operation, rapidity, and no need for large-scale instruments. Through the synergistic effect among three substances, it can be judged by the naked eye whether the organophosphorus pesticide exceeds the standard according to the color change, and it can realize the real-time detection of whether the organophosphorus pesticide exceeds the standard, and the detection is not restricted by the site. Description of the drawings

[0019] Figure 1 It is the TEM characterization diagram of the CeO2 nanomaterial prepared in Example 1.

[0020] Figure 2 It is the color of the liquid when detecting the parathion-type organophosphorus pesticide residue in potato peel in Example 2.

[0021] Figure 3 It is the color of the liquid when detecting the parathion-type organophosphorus pesticide residue in pear peel in Example 6.

[0022] Figure 4 It is the color principle diagram when detecting the color in pear peel in Example 6. Detailed implementation manners

[0023] The present invention will be further described in detail below with reference to the drawings and specific embodiments, but the protection scope of the present invention is not limited to the content described.

[0024] Example 1

[0025] A kit for detecting paraoxon-type organophosphorus pesticides, which includes: a methanol solution (obtained by mixing anhydrous methanol and water in a volume ratio of 1:1), a cerium dioxide nano-dispersion, and a sodium hydroxide solution with a concentration of 5 mol / L. The preparation method of the cerium dioxide nano-dispersion is as follows:

[0026] (1) Weigh 0.9984 g of NaOH solid and 0.8684 g of Ce(NO3)3·6H2O solid and dissolve them respectively to obtain a NaOH solution and a Ce(NO3)3 solution. Under stirring, mix the NaOH solution and the Ce(NO3)3 solution evenly to obtain a mixed solution.

[0027] (2) Transfer the mixed solution to a reaction kettle, place the reaction kettle in an oven at 100 °C and continue to react for 20 h. Finally, centrifuge, wash, dry and grind the obtained solid to obtain CeO2 powder.

[0028] (3) Disperse the CeO2 powder prepared in step (2) into deionized water to obtain a cerium dioxide nano-dispersion with a concentration of 2.0 mg / mL.

[0029] Figure 1 The TEM characterization diagram of the CeO2 nanomaterial prepared in this example is as Figure 1 shown. It can be seen from the figure that CeO2 is rod-shaped, with a length of about 30 - 50 nm, an average diameter of about 10 nm, a lattice fringe spacing of 0.28 nm, and the lattice fringes are relatively evenly distributed.

[0030] Example 2

[0031] Use the kit described in Example 1 to detect whether the organophosphorus pesticides on the surface of potatoes exceed the standard. The steps are as follows:

[0032] (1) Take potato peels, add a methanol solution with a volume 5 times that of the potato peels, stir for 10 min and then let it stand for 5 min.

[0033] (2) Take out the potato peels in step (1), keep the liquid, add an equal volume of cerium dioxide nano-dispersion and an equal volume of sodium hydroxide solution to the liquid, mix evenly, and observe the color change. When the solution is yellow, there are residual paraoxon-type organophosphorus pesticides in the sample; when the solution does not change, there are no residual paraoxon-type organophosphorus pesticides in the sample. The color change in this example is as Figure 2 shown. It can be seen from the figure that the color of the liquid does not change, indicating that there are no residual paraoxon-type organophosphorus pesticides in the potato peels tested this time.

[0034] Example 3

[0035] The residue of parathion - type organophosphorus pesticides on apple peels was detected by the same method as in Example 2. In this example, the color of the final liquid did not change, indicating that there was no residue of parathion - type organophosphorus pesticides in the apple peels tested this time.

[0036] Example 4

[0037] The residue of parathion - type organophosphorus pesticides on cucumber peels was detected by the same method as in Example 2. In this example, the color of the final liquid did not change, indicating that there was no residue of parathion - type organophosphorus pesticides in the cucumber peels tested this time.

[0038] Example 5

[0039] The residue of parathion - type organophosphorus pesticides on Chinese cabbages was detected by the same method as in Example 2. In this example, the color of the final liquid did not change, indicating that there was no residue of parathion - type organophosphorus pesticides in the Chinese cabbages tested this time.

[0040] Example 6

[0041] The residue of parathion - type organophosphorus pesticides on pear peels was detected by the same method as in Example 2. The test results are as Figure 3 shown. It can be seen from the figure that the color of the final liquid turned yellow, indicating that there was a residue of parathion - type organophosphorus pesticides in the pear peels tested this time.

Claims

1. A kit for real-time detection of paraoxon-type organophosphorus pesticides, characterized in that: The kit includes: a methanol solution, a cerium dioxide nano-dispersion, and a sodium hydroxide solution.

2. The kit for real-time detection of paraoxon-type organophosphorus pesticides according to claim 1, characterized in that: The methanol solution is obtained by mixing anhydrous methanol and water in a volume ratio of 1:

1.

3. The kit for real-time detection of paraoxon-type organophosphorus pesticides according to claim 1, characterized in that: The concentration of the sodium hydroxide solution is 3.875 - 7.75 mol / L.

4. The kit for real-time detection of paraoxon-type organophosphorus pesticides according to claim 1, characterized in that: The preparation method of the cerium dioxide nano-dispersion is as follows: (1) Dissolve solid NaOH and solid Ce(NO3)3·6H2O respectively to obtain a NaOH solution and a Ce(NO3)3 solution, and mix the NaOH solution and the Ce(NO3)3 solution evenly under stirring to obtain a mixed solution; (2) Dry the mixed solution, dry and grind the solid after centrifugal washing to obtain CeO2 powder; (3) Disperse the CeO2 powder into deionized water to obtain a cerium dioxide nano-dispersion.

5. The kit for real-time detection of paraoxon-type organophosphorus pesticides according to claim 4, characterized in that: In step (1), the mass ratio of solid NaOH to solid Ce(NO3)3·6H2O is 1:1 - 1.2:

1.

6. The kit for real-time detection of paraoxon-type organophosphorus pesticides according to claim 4, characterized in that: In step (2), the drying temperature is 90 - 110 °C, and the drying time is 15 - 25 h.

7. The kit for real-time detection of paraoxon-type organophosphorus pesticides according to any one of claims 1 or 4, characterized in that: The concentration of the cerium dioxide nano-dispersion is 1.8 - 2.0 mg / mL.

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