Comparative evaluation of ELISA kits' reliability for the aflatoxin M1 determination in goat milk

Enzyme-linked immunosorbent assay (ELISA) is widely used in the food industry for detecting aflatoxin M-1 (AFM(1)) in milk. The purpose of this survey was to compare the performance of three ELISA kits for the determination of AFM(1) in goat milk by evaluating specific performance parameters such as precision, accuracy, repeatability and specificity, with AFM(2) coexistence. Goat milk, with known AFM(1) concentration (5 ng l(-1)), was spiked with AFM(1) at 12.5, 25, 50, 75 and 100 ng l(-1) and also with AFM(2) in the same concentrations. At extremely low concentrations of AFM(1) (17.5 ng l(-1)), all kits were imprecise, while by increasing the AFM(1) concentration, at levels close to or higher than the maximum tolerable limit (55, 80 and 100 ng l(-1)) precision significantly improved for all kits. All kits presented high repeatability and fairly good specificity, regardless of the AFM(2) presence that was examined for the first time.