Matrix effect of cucumber on fenitrothion and imidacloprid residue analysis by a commercially available ELISA kit

Abstract

The matrix interference of cucumber was investigated using a commercially available ELISA kit to analyze residual fenitrothion and imidacloprid. The recovery rate was over 150% in a sample with low concentration pesticides (fenitrothion; 0.04 µg/g, imidacloprid; 0.2 µg/g); therefore, the ELISA kit was not practical for screening pesticide residue at low concentrations. Cucumber fruits were divided into three organs: a fruit receptacle including an exocarp, mesocarp, and placenta including a seed. The extract of the fruit receptacle controlled the optical density value, which was notably confirmed on fenitrothion measurement. The recovery rate of the sample processed by ultrafiltration was greatly improved. © 2006, Pesticide Science Society of Japan. All rights reserved.