Development and validation of an immunochromatography test strip for rapid detection of pyrimethanil residues

Pyrimethanil is one of anilinopyrimidine fungicides widely used in crop protection and frequently found in a variety of crops, including fruits, vegetables, and cereals. This paper describes the development of the first reported immunochromatography test strip (ICTS) based on colloidal gold-labeled monoclonal antibody for the detection of pyrimethanil. Under optimal conditions, the visual cut-off value of ICTS for pyrimethanil was 40 ng/mL. Using a portable strip reader, the 50% inhibition concentration and calculated LOD of pyrimethanil in the PBS samples were 4.8 and 0.9 ng/mL, respectively. When used to analyse fortified samples of fruit and vegetable, acceptable recovery rates of 83.3-105.7% with the coefficient of variation values below 11.7% were obtained. Analysis of blindly fortified samples by the proposed ICTS gave similar results to those of the ic-ELISA and HPLC-MS/MS methods. These results indicate the proposed ICTS is a rapid, simple analytical method for quantitative on-site monitoring of pyrimethanil in foodstuffs.