Determination of Ochratoxin a in Cereals and Feed by SAX-SPE Clean Up and LC Fluorimetric Detection

Abstract

We have developed a sensitive, reliable and highly specific method for the determination of ochratoxin A (OA) in cereals and animal feed. The samples were extracted in acidified acetonitrile and, they were then thoroughly purified by a new procedure combining a pH-controlled liquid-liquid partition with a strong anionic exchange solid-phase extraction. Both RP-TLC and RP-HPLC methods for semi-quantitative and quantitative determination have been described respectively, together with a RP-HPLC confirmation procedure, via conversion to OA-methyl ester. The TLC and HPLC determination limits were 8.0 ng/g and 0.10 ng/g respectively. The mean recovery from spiked samples was 95%.