Determination of aflatoxins by enzyme‐linked immunosorbent assay with special reference to aflatoxin M 1 in raw milk

There is an increasing requirement for the screening of animal feedstuffs, plant products and edible animal tissues for human consumption, for the presence of contamination by aflatoxins. An enzyme‐linked immunosorbent assay is described which may be used to determine aflatoxins in raw milk at 0.1μg litre −1 and in extracted feedstuffs at the level of 5μgkg −1 . The method includes a novel conjugation procedure allowing heterologous conjugates to be prepared resulting in increased sensitivity without interference by sample matrix effects. Suitably cross‐reactive antisera were produced using the cyclopentanone ring of the aflatoxin molecule as the principal immunogenic determinant.