International mycotoxin check sample survey program. Part III. Report on performance of participating laboratories for determining ochratoxin A in animal feed.

A sample of animal feed made from barley, naturally contaminated at about 1000 micrograms ochratoxin A/kg, was analyzed by 44 laboratories in 24 countries. The AOAC method for determining ochratoxin A in barley was used by 27 (61%) of the participating laboratories. Results from laboratories using this method were grouped around 2 maxima: one below 100 micrograms/kg and a second near 940 micrograms/kg, the median concentration for results reported by all 44 participating laboratories. Results from laboratories using methods other than the AOAC method were more widely distributed with no apparent maximum near 1000 micrograms/kg.