Method for detecting thiamethoxam residues

A technology of thiamethoxam and antigen, which is applied in the field of detection of thiamethoxam residues, can solve problems such as poor sensitivity, enzyme activity and stability susceptible to environmental interference, and difficult quantitative analysis, achieving high accuracy and reliability, and solving Trace determination, good selectivity effect

Pending Publication Date: 2020-04-24
HEBEI ACADEMY OF AGRI & FORESTRY SCI INST OF GENETICS & PHYSIOLOGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Conventional pesticide residue instrumental analysis methods include gas chromatography, high performance liquid chromatography, and gas/liquid chromatography-mass spectrometry (GC/LC-MS). These methods have cumbersome detection steps, long time, and high requirements for instruments. , cannot meet the needs of on-site rapid and large-scale sample screening, and there is an urgent need to explore and develop accurate, convenient, sensitive, reliable, and applicable rapid detection methods for pesticide residues
At present, the more mature commerc

Method used

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  • Method for detecting thiamethoxam residues
  • Method for detecting thiamethoxam residues
  • Method for detecting thiamethoxam residues

Examples

Experimental program
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preparation example Construction

[0027] The present invention does not specifically limit the source of up-conversion nanoparticles and thiamethoxam antibodies, and commercially available products can be used. Preferably, the preparation method of the thiamethoxam antibody-UCNPs conjugate includes: using COOH-UCNPs particles with NN-hydroxysuccinimide (NHS) and 1-ethyl-(3-dimethylaminopropyl) The carbodiimide (EDC) is vibrated and activated in an aqueous solution to obtain active particles; the active particles and the thiamethoxam antibody are mixed and reacted in a phosphate buffer to obtain the thiamethoxam antibody-UCNPs conjugate. Preferably, the active particles are washed with phosphate buffer solution and then reacted with thiamethoxam antibody. It is more preferable to rinse in ultrasonic waves. The preferred concentration of the phosphate buffer in the present invention is 0.01M and the pH value is 7.4. In the present invention, it is preferred that the active particles react with the thiamethoxam ...

Embodiment 1

[0037] Preparation of thiamethoxam antibody conjugate

[0038] First, prepare an ultrapure aqueous solution of 0.5 mg / mL COOH-UCNPs particles, add 20 μL NHS (25 mg / mL) and 20 μL EDC (38 mg / mL), shake vigorously for 20 minutes to activate the particles, and then centrifuge for 10 minutes. Discard the supernatant and retain the precipitated active particles. Wash the precipitate with 1 mL of 0.01M phosphate buffer (PB, pH 7.4) under ultrasound for 5 minutes. Subsequently, 19 μL of thiamethoxam antibody (2.1 mg / mL) was added to the UCNPs activation suspension. The mixture was reacted at 250 rpm for 2 hours, and then a 1% bovine serum albumin solution was added to the mixture to block for 30 minutes. After centrifugation, discard the supernatant and resuspend the sediment in 0.03 containing 1% bovine serum albumin (w / v), 0.1% Tween-20 (v / v) and 1% trehalose (w / v) M PB (pH 7.4) stock solution. Thiamethoxam antibody UCNPs are stored at 4°C. If the particles become aggregated or flo...

Embodiment 2

[0046] Sample pretreatment and standard addition recovery test

[0047] Buy apples, peaches, and cucumbers from supermarkets. In the sample pretreatment, the samples are highly homogenized and turned into liquid juice. They are first confirmed to be free of thiamethoxam by UPLC-MS / MS. It is also used in the standard recovery test. A small amount of thiamethoxam was added to each sample to obtain different spiked levels. Each sample (2.0 g) was extracted with 10 mL of 0.01 M PBS (pH 7.4) with shaking for 1 minute, and then filtered through a 0.22 μM membrane. The filtrate was diluted 4 times with 0.01m PBS (pH 7.4) and analyzed.

[0048] Test actual samples

[0049] In practical application, using IFE-based immunoassay and UPLC-MS / MS technology, 15 samples of apples, peaches and cucumbers from different origins were analyzed simultaneously to evaluate the correlation between the two methods.

[0050] Table 1 Using the method of Example 1 to detect the recovery rate of the added samp...

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Abstract

The invention provides a method for detecting thiamethoxam residues, and belongs to the technical field of pesticide residue detection. In the invention, an energy donor UCNPs is coupled with a thiamethoxam antibody, and an energy receptor AuNPs is used for marking a thiamethoxam antigen. A competitive immune reaction is performed between thiamethoxam and the antigen AuNPs combined with the antibody UCNPs, and a thiamethoxam residue content is calculate and acquired by using a fluorescence detection signal. The method for detecting the thiamethoxam residues has advantages of high sensitivity,good selectivity, high accuracy and high reliability, and is suitable for on-site, batch and rapid detection.

Description

Technical field [0001] The invention relates to the technical field of pesticide residue detection, in particular to a method for detecting thiamethoxam residue. Background technique [0002] Thiamethoxam (thiamethoxam) is the first representative compound of the second generation of neonicotinoid insecticides. It was developed by Swiss Novartis (now Syngenta) in 1991 and launched in 1997. Thiamethoxam not only has contact killing, stomach toxicity, systemic activity, but also has higher activity, better safety, wider insecticidal spectrum, fast action speed, long lasting period, etc. It can selectively inhibit insects The nicotinic acid acetylcholinesterase receptor in the central nervous system blocks the normal conduction of the insect central nervous system, causing paralysis and death of the insects. It is highly active against Lepidoptera, Coleoptera, Diptera, especially Homoptera pests, and can effectively control various aphids, leafhoppers, planthoppers, whiteflies, pot...

Claims

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Application Information

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IPC IPC(8): G01N33/53G01N33/543G01N33/58
CPCG01N33/5308G01N33/54346G01N33/582G01N2430/10
Inventor 张嘉坤钱训郑振山陈勇达李丽梅张少军
Owner HEBEI ACADEMY OF AGRI & FORESTRY SCI INST OF GENETICS & PHYSIOLOGY
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