Okazaki Fumiko, Hirakawa Yuki, Yamaguchi-Murakami Yukie, Harada Ayako, Watanabe Eiki, Iwasa Seiji, Narita Hiroshi, Miyake Shiro
Kyoto Women's University.
Shokuhin Eiseigaku Zasshi. 2014;55(2):65-72. doi: 10.3358/shokueishi.55.65.
A direct competitive (dc)-ELISA was developed for rapid and simple determination of chlorothalonil residue in vegetables. A carboxylic acid derivative of pentachlorophenol was used to prepare an anti-chlorothalonil monoclonal antibody (MoAb) that showed adequate reactivity for dc-ELISA. Before homogenization of vegetable samples, phosphoric acid was added (vegetable-10% phosphoric acid (2 : 1, w/v)) to block enzymatic decomposition of chlorothalonil. The use of phosphate buffer (100 mmol/L, pH 7.0) minimized the influence of phosphoric acid on competitive reaction in the dc-ELISA. Working range was 0.10 to 6.0 ng/mL in the optimized dc-ELISA. The recovery of chlorothalonil spiked in cucumber and eggplant was 97.1 to 125%. The results correlated well with those obtained by HPLC analysis. The dc-ELISA could rapidly determine chlorothalonil after a simple sample preparation procedure.
