Watanabe E, Watanabe S, Ito S, Hayashi M, Watanabe T, Yuasa Y, Nakazawa H
Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
J Agric Food Chem. 2000 Nov;48(11):5124-30. doi: 10.1021/jf000055k.
Imazalil has been widely used in citrus fruits such as lemons, oranges, and grapefruits. A competitive enzyme-linked immunosorbent assay (ELISA) was developed for the detection of residual imazalil in citrus fruits. A monoclonal antibody (MoAb) generated to the synthetic imazalil hapten (EIT-0073)-protein conjugate was used. This assay was applied to lemon, orange, and grapefruit matrices for an imazalil analysis. The acceptable residue level for lemons, oranges, and grapefruits in Japan is 5 ppm. The matrix interference was minimized by direct dilution of the sample homogenate. No further cleanup was needed. The detection limit for imazalil in these citrus fruits was 0.1 ng/mL. The recovery of each fortified citrus fruit sample was >81.0%. The imazalil recovery measured by the proposed ELISA was compared to the recovery determined by a conventional HPLC. A good correlation was observed between the proposed ELISA and the HPLC. This proposed ELISA would be useful for monitoring for residual imazalil.
