title: Direct enzyme-linked immunosorbent assay for determining aflatoxin M1 at picogram levels in dairy products.
abstract: Protocols for detecting picogram quantities of aflatoxin M1 in dairy products were established. Milk samples were subjected to a reverse phase Sep-Pak C18 cartridge treatment before analysis by an enzyme-linked immunosorbent assay (ELISA) according to previously published procedures. M1 in yogurt, brick cheddar, and ripened Brie cheese was extracted by a modified Pons method, subjected to a normal phase silica cartridge treatment, and analyzed by ELISA. The detection limits for M1 in milk, yogurt, cheddar, and Brie were 10, 10, 50, and 25 ppt (ng/kg), respectively. Recovery for M1 added to these products was in the range 70-110%. Good agreement was found for M1 levels in several naturally contaminated milk samples analyzed by both ELISA and liquid chromatography.
mesh_terms: D016607:Aflatoxin M1; D000348:Aflatoxins / Q000032:analysis*; D000818:Animals; D002417:Cattle; D002611:Cheese / Q000032:analysis; D003611:Dairy Products / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D005516:Food Microbiology; D008892:Milk / Q000032:analysis; D015014:Yogurt / Q000032:analysis
chemical_list: D000348:Aflatoxins; D016607:Aflatoxin M1