Investigation of interference from agricultural sample with ELISA for the residue determination of triazophos and circumventing matrix effects

Matrix interference is a common challenge for pesticide analysis in food by immunoassay.Carrot,spinach,banana,pear,rice grain and peanut were selected to investigate the matrix interference with ELISA for triazophos.The results indicated that matrix interference from banana primarily inhibited enzyme activity,and spinach,pear,rice grain mainly hindered antigen and antibody interaction.For carrot and peanut samples,matrixes interfered with not only enzyme activity,but also antigen and antibody interaction.When agricultural sample extracts were diluted ten-fold with 0.3% skimmed milk,0.1mmol/L EDTA,2.5% methanol PBS followed by a centrifugation at 12 000 r/min for 10 min,the matrix effect can be eliminated.The results confirmed that ELISA is suitable for the residue determination of triazophos in agricultural samples as a simple,effective method.