title: Development of direct competitive ELISA for residue analysis of fungicide chlorothalonil in vegetables.
abstract: 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.
authors.affiliation: Kyoto Women's University.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Okazaki
authors.forename: Yuki
authors.initials: Y
authors.lastname: Hirakawa
authors.forename: Yukie
authors.initials: Y
authors.lastname: Yamaguchi-Murakami
authors.forename: Ayako
authors.initials: A
authors.lastname: Harada
authors.forename: Eiki
authors.initials: E
authors.lastname: Watanabe
authors.forename: Seiji
authors.initials: S
authors.lastname: Iwasa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Narita
authors.forename: Shiro
authors.initials: S
authors.lastname: Miyake
mesh_terms: D000911:Antibodies, Monoclonal; D018553:Cucumis sativus / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005504:Food Analysis / Q000379:methods*; D005659:Fungicides, Industrial / Q000032:analysis*; D009570:Nitriles / Q000032:analysis* / Q000276:immunology; D010573:Pesticide Residues / Q000032:analysis*; D010756:Phosphoric Acids; D012680:Sensitivity and Specificity; D032323:Solanum melongena / Q000737:chemistry; D014675:Vegetables / Q000737:chemistry*
chemical_list: D000911:Antibodies, Monoclonal; D005659:Fungicides, Industrial; D009570:Nitriles; D010573:Pesticide Residues; D010756:Phosphoric Acids; C030242:phosphoric acid; C005806:tetrachloroisophthalonitrile