Electrochemical detection method of organophosphorus pesticide

An organophosphorus pesticide and detection method technology, applied in the field of food safety detection and analytical chemistry, can solve the problems of cumbersome process operation, differences in catalytic selectivity and catalytic activity, inability to realize on-site detection, etc., to avoid poor repeatability and save detection time. Effect

Active Publication Date: 2017-03-22
NANJING NORMAL UNIVERSITY
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Chromatographic analysis methods require large-scale analytical instruments, the process is cumbersome, and on-site detection cannot be realized; the enzyme inhibition method occupies a place in the field of rapid detection of organic phosphorus due to the advantages of miniaturization of instruments and short detection time.
However, due to the various sources of enzymes used, their catalytic selectivity and catalytic activity vary greatly, which has a negative impact on the repeatability and reliability of actual detection.

Method used

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  • Electrochemical detection method of organophosphorus pesticide
  • Electrochemical detection method of organophosphorus pesticide
  • Electrochemical detection method of organophosphorus pesticide

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] Example 1 Preparation of an electrochemical sensor for the detection of organophosphorus pesticides

[0034] (1) Preparation of graphene‐chitosan‐parathion complex

[0035] Graphene (10mg) is added in 4mL chitosan solution (mass concentration is 1g / L), at room temperature ultrasonic dispersion 30min (rotating speed is 5000rpm), then add 2ml parathion solution (mass concentration is 0.2g / L) , continue to sonicate for 30 min, and store in a refrigerator at 4°C until use.

[0036] The UV-Vis absorption spectra of graphene‐chitosan‐parathion composites are as follows: figure 1 shown. The maximum absorption peak of graphene-chitosan dispersion is 262nm, the maximum absorption peak of parathion is 272nm, and the maximum absorption peak of graphene-chitosan-parathion composite is 267nm, located in graphene-chitosan sugar and parathion, indicating that a graphene-chitosan-parathion complex has been formed.

[0037] (2) Preparation of electrochemical sensor: the glassy carbo...

Embodiment 2

[0039] The detection of embodiment 2 organophosphorus pesticide standard samples

[0040] In this example, standard samples of organophosphorus pesticides are detected respectively. , fenthion and trichlorfon.

[0041]The electrochemical sensors prepared in Example 1 were respectively immersed in organophosphorus pesticides with concentrations of 0ng / mL, 1ng / mL, 10ng / mL, 50ng / mL, 100ng / mL, 200ng / mL, 400ng / mL, 600ng / mL, Incubate in 800ng / mL, 1200ng / mL and 1500ng / mL incubation solutions (all of which contain AchE at a concentration of 10μg / mL), rinse with phosphate buffer solution, and in K 3 [Fe(CN) 6 Carry out differential pulse voltammetry (DPV) scan in the solution, record response current; The response current of blank standard sample is I 0 , the response current of the standard sample containing organophosphorus is I x , the increasing value ΔI of the response current is equal to I x with I 0 The difference of the difference; the ΔI and the concentration C of organi...

Embodiment 3

[0048] The standard addition detection of chlorpyrifos in embodiment 3 apples

[0049] Weigh the cleaned apple samples (three parallel samples, each with a mass of 50±0.005g) into a beaker, add chlorpyrifos standard solution, then add 50mL water and 100mL acetone, grind and extract with a chopper for 3min. After filtration, take 100 mL of filtrate and place it in a separatory funnel, add 15 g of sodium chloride, shake vigorously for 3 minutes and then let it stand still. After the solution is separated, extract the aqueous phase with 50 mL of dichloromethane, and combine the acetone and dichloromethane extracts. Dry it with anhydrous sodium sulfate to remove the water, concentrate it by rotary evaporation to about 2mL, blow dry the remaining liquid with nitrogen, and finally add 10mL of ethanol-water solution (V:V=1:1), shake until dissolved, and store in low temperature and shade for later use .

[0050] Prepare a blank sample without adding chlorpyrifos according to the abo...

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Abstract

The invention discloses an electrochemical detection method of organophosphorus pesticide. The detection method comprises the following steps: preparing a graphene-chitosan-parathion compound modified electrochemical sensor at first; then taking K3[Fe (CN)6] as a probe; carrying out differential pulse voltammetry (DPV) scanning on the basis of a principle that acetylcholin esterase can be strongly combined with organophosphorus pesticide; recording response current; and analyzing and deducing related data to obtain the concentration of the corresponding organophosphorus pesticide in a sample to be detected. By the detection method, the detection limit of the organophosphorus pesticide is between 0.012 ng/mL and 0.23 ng/mL, and the linear range is 1-1,500 ng/mL. The electrochemical detection method of organophosphorus pesticide ahs the beneficial effects that compared with another method for rapidly detecting the organophosphorus pesticide by using an enzymatic inhibition method, the detection method has the characteristics that enzymatic reaction is not required, therefore, detection time is greatly saved, and meanwhile, the problem that the repeatability of a detection result is poor due to the fact that enzymes from different sources are adopted is also avoided.

Description

technical field [0001] The invention belongs to the technical field of food safety detection and analytical chemistry, and relates to an electrochemical detection method for organophosphorus pesticides, in particular to a detection method based on the strong binding effect of acetylcholinesterase and organophosphorus pesticides. Background technique [0002] my country is a large agricultural country, and its annual output of imported and exported agricultural products ranks first in the world. Organophosphorus pesticides have gradually become the most widely used insecticides in my country due to their characteristics of various varieties, high efficacy, and broad insecticidal spectrum. While organophosphorus pesticides have brought huge economic benefits to our country, they have also brought great harm to food safety and ecosystems. In recent years, acute poisoning incidents of organophosphorus pesticides have occurred frequently, such as the incident of phorate seriousl...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N27/48
CPCG01N27/48
Inventor 赵波杨琦邵科峰周斌华
Owner NANJING NORMAL UNIVERSITY
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