Field Evaluation of Immunoassays for Aflatoxin Contamination in Agricultural Commodities

Abstract

Four commercially available aflatoxin test kits based on immunochemical technology were used to monitor aflatoxin contamination in whole cottonseed under non-laboratory conditions. The kits, utilizing monoclonal antibodies to measure aflatoxin levels, can be divided into two categories: enzyme-linked immunosorbent assay (ELISA) and affinity columns. Assays were performed at cotton gins, dairy farms, feed mills, ammoniation plants and cotton oil processing plants under varying environmental conditions. Results from these locations were compared to those obtained in the laboratory using the same kits and thin layer chromatography (TLC). Preliminary results show good agreement between on-site and laboratory kit performance. Agreement between kits was 92% on-site and 83% in the laboratory. These results indicate that the kits are suitable for use under nonlaboratory conditions. Aflatoxin stability in aqueous methanol extracts was determined using the immunochemical kits and TLC. Aflatoxin concentration decreased by almost 40% after 4 days.