Method for fast detection of multiple residues of three insecticides including imidacloprid and the like in tea and test strip adopted by method

A technology with many pesticide residues and imidacloprid, which is applied in the field of gold standard immunoassay detection of small molecule compounds, can solve the problems of high detection false positive rate, excessive chlorinated nicotine pesticides, and inability to quickly screen on-site, so as to improve sensitivity, Good practicability and the effect of result visualization

Active Publication Date: 2015-12-23
杭州佰盛汇星生物科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In August 2014, when the Qingdao Entry-Exit Inspection and Quarantine Bureau conducted a sampling inspection on a batch of imported oolong tea, it was found that imidacloprid exceeded the standard by 2 times, and imported tea also had the problem of chlorinated nicotine pesticide exceeding the standard.
So far, the common on-site rapid screening method for pesticide residues is the enzyme inhibition chromogenic disc method, but its detection rate is high, the detection object is limited to organophosphorus and carbamate pesticides, and it has a high specificity. Sex is not high
In recent years, immunochemical analysis based on antigen-antibody specific reaction is one of the research hotspots in the rapid detection of pesticide residues. Among them, the most reported one is enzyme-linked immunosorbent assay (ELISA), and many types of pesticide ELISA have been developed. The kit does have potential market application prospects, but the detection requires multi-step reactions, and it still cannot really achieve on-site rapid screening

Method used

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  • Method for fast detection of multiple residues of three insecticides including imidacloprid and the like in tea and test strip adopted by method
  • Method for fast detection of multiple residues of three insecticides including imidacloprid and the like in tea and test strip adopted by method
  • Method for fast detection of multiple residues of three insecticides including imidacloprid and the like in tea and test strip adopted by method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] Embodiment 1: test strip preparation

[0044] 1. Preparation of colloidal gold

[0045] Colloidal gold particles were prepared by trisodium citrate (sodium citrate) reduction method. 150mL0.01% (mass%) chloroauric acid solution is heated to boiling (about 120 ℃) ​​under oil bath condition, add 2.5mL1% (mass%) trisodium citrate aqueous solution rapidly under magnetic stirring, when the color of solution When it turns bright red completely, continue to reflux for 5-10 minutes and then stop heating. After cooling, put the solution into a reagent bottle and store it in a refrigerator at 4°C. A colloidal gold solution with a mass concentration of 0.01% was obtained.

[0046] The colloidal gold particles were scanned in the visible light range by a UV-visible spectrophotometer, and the maximum absorption wavelength λmax was measured to be 520nm, and the absorbance value was 0.80; the colloidal gold particles were observed under a transmission electron microscope, and the si...

Embodiment 2

[0065] Example 2: Application

[0066] 1. Test strip sensitivity test

[0067] (1) Standard solution preparation

[0068] Standard stock solutions of three pesticides, imidacloprid, clothianidin and chlorothiamid, were prepared with methanol, and the concentrations of the standard stock solutions were all 1 mg / L. Then dilute imidacloprid, clothianidin, and clothhirid with 0.01MPBS buffer solution to the standard working solutions of serial concentrations: 0.1mg / L, 0.01mg / L, 0.005mg / L, 0.002mg / L, 0.001mg / L.

[0069] (2) Standard solution detection

[0070] Set 13 treatment groups, respectively blank control (0.01MPBS buffer solution), imidacloprid 0.01mg / L, 0.005mg / L, 0.002mg / L, 0.001mg / L, clothianidin 0.01mg / L, 0.005mg / L , 0.002mg / L, 0.001mg / L, chlorothialine 0.01mg / L, 0.005mg / L, 0.002mg / L, 0.001mg / L. Use the same batch of residual speed test paper strips for detection, and repeat twice for each treatment group. The detection method is: take a tea soup sample and add 2 dro...

Embodiment 3

[0103] Example 3: Change the "chlorothialine-OVA conjugate" in step 5) of Example 1 to "clothianidin-OVA conjugate", and the clothianidin-OVA conjugate can be prepared according to the following references Obtained: LiM., ShengE., CongL., etal., 2013. Development of Immunoassays for Detecting Clothianidin Residue in Agricultural Products. JAgrFoodChem61 (15): 3619-3623. The coupling ratio of clothianidin hapten and OVA is 10:1. The rest of the test strip manufacturing process is identical to Example 1. The sample detection process is equivalent to the step (3) of the applied experiment 1) in Example 2.

[0104] The results obtained are as follows:

[0105] Under the condition of spiked tea soup matrix, the detection sensitivities of imidacloprid, clothianidin and clothiaprid were all 0.005 mg / L, that is, the minimum detection limit was 0.005 mg / L. The results showed that the effect of the detection line coating using heterologous competitive clothianidin-OVA conjugates or cl...

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Abstract

The invention discloses a heterogenous competitive immuno-chromatographic gold labeled test strip suitable for fast detection of multiple residues of three chloronicotinyl insecticides including imidacloprid and the like in tea. The test strip comprises a lining plate, a sample pad, a gold labeled primary antibody conjugate pad, a nitrocellulose membrane and a water absorption pad, wherein the gold labeled primary antibody conjugate pad is coated with a colloidal gold labeled imidacloprid specific mouse monoclonal antibody, the nitrocellulose membrane is coated with a detection line for an heterogenous competitive imidaclothiz or clothianidin artificial antigen and a quality control line coated with rabbit anti-mouse IgG. The invention further provides a corresponding fast detection method. According to the method, 2 to 3 drips of tea infusion are dropwise added into a sample application area of the sample pad to perform chromatographic reaction, and the positive and negative results of the insecticides in a sample are directly judged according to the color developing situations of the detection line and the quality control line after 5-10 minutes.

Description

technical field [0001] The invention belongs to the field of gold standard immunoassay detection of small molecule compounds, and in particular relates to a gold standard speed test paper strip for pesticide residues based on direct competitive immunochromatography, the test strip is suitable for chloronicotine pesticides in tea samples Multi-residue rapid detection of imidacloprid, clothianidin and clothiaprid. Background technique [0002] Since the United States, the European Union, and Japan have strengthened the quarantine and inspection of imported food and agricultural products, my country's tea export has shown a sharp decline. The main reason is that excessive pesticides have plagued my country's tea export. In recent years, due to the high frequency of use of imidacloprid and other chloronicotinoid pesticides on tea, the detection rate of imidacloprid and other pesticides on tea is high. In August 2014, when the Qingdao Entry-Exit Inspection and Quarantine Bureau ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N33/53G01N33/532
CPCG01N33/53G01N33/532
Inventor 朱国念赵颖柳颖杨斌郭逸蓉方一画司芳芳程敬丽
Owner 杭州佰盛汇星生物科技有限公司
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