Development Of Gei-based Immunoaffinity Test Column For The Detection Of Pesticide Residues In Food

In this paper,atrazine,nitenpyram and anilofos were used as research objects to develop a single-residue and multi-residue immunoaffinity test columns(IATC)for detecting the above pesticides.They were developed for rapid screening of these pesticides in food samples.The antibody gel of these pesticides were prepared by respectively coupling the antibodies of atrazine,nitenpyram and anilofos to CNBr-activated Sepharose 4B.Coupling HRP antibody to CNBr-activated Sepharose 4B to prepare HRP antibody gel.The test column is a 1 mL(SPE)solid phase extraction column,which was divided into the test layer(anti-atrazine,anti-nitenpyram and anti-anilofos antibody-coupled gel)and the control layer(anti-HRP antibody-coupled gel).Each colloid is fixed by two polyethylene gaskets.Based on horseradish peroxidase enzymatic reaction,the test results could be evaluated visually.Basically,bule color development represented the negative results,while the absence of color development reprensented the positive results.The immunoaffinity test columncould be achieved qualitative and semi-quantitative detection for pesticides in samples.The limits of detection(LOD)of atrazine,nitenyram and anilofos were 1 ?g/L,5?g/L,5 ?g/L.The LOD of atrazine and nitenpyram by a multi-residue immunoaffinity gel test column were 1 ?g/L,5 ?g/L respectively.Specific assays showed that the atrazine immuno-affinity gel column has a relatively large cross-reaction for testing propazine,so the method can be used to simultaneously test atrazine and propazine.The nitenpyram immuno-affinity test method had a good specificity and had less cross-reaction with structural analogs.The anilofos immuno-affinity test method had a good specificity and had less cross-reaction with structural analogs.The sample preparation by using the four methods of immuno-affinity gel test column established in this study were very simple.The water sample can be directly used for detection without any treatment,and the juice can be used for detection after being diluted with PBS.Cereals were extracted by organic solvent(methanol)and diluted with PBS for detection.Ultimately,the detection limit of water and cereal samples of the arazine IATC respectively were 1 ?g/L and 10 ?g/kg.The detection limit of water,juice and cereal samplesof the nitenpyram IATC respectively were 1 ?g/L,50 ?g/L and 50 ?g/kg.The detection limit of water,and cereal samples of the anilofos IATC respectively were 5 ?g/L and 50 ?g/kg.Because of its fast detection,simple sample preparation,low cost,easy-to-judgment by vision,the test column could be served as an on-site screening of a large number of arazine,nitenpyram and anilofos residues in samples.