Different extraction mixtures involving acetonitrile:water and methanol:water was examined for the extraction efficiency of coprameal that had been spiked with 10 ng g1 aflatoxin standards.Of the combinations investigated, using acetonitrile:water (9:1)and methanol:water (8:2) are more suitable than the others (Fig. 2). Using acetonitrile:water (9:1) gave more satisfactory
recoveries, all the aflatoxins were at least 85% extracted. This is further supported by the recovery results when 5–30 ng g1 aflatoxins were spiked and next extracted using methanol:water and acetonitrile:water (Fig. 3). Recoveries of aflatoxin G1 is significantly lower when extracted using methanol:water mixture.