Simultaneous determination of abamectin and doramectin in soil from a grazed pasture

The use of antihelmintics in veterinary medicine, especially avermectins (ivermectin, abamectin, doramectin) has been increasing rapidly in recent years. They cause a serious ecotoxicological problem because of their specific metabolism and their action on non-target organisms. An analytical procedure for simultaneous determination of abamectin and doramectin in soil from a grazed pasture has been developed. Classical extraction procedure for extraction of both avermectins, from soil, a solid phase extraction (SPE) for the clean-up of extracts and a high performance liquid chromatography (HPLC) with fluorescence detection were introduced in the analytical procedure. Low detection limit (0.5 ng/g of dry soil), good selectivity, recovery of the method in a range of 71-96%, good repeatability (>90%) and limit of quantification of 0.7 and 1.5 ng/g of dry soil for abamectin and doramectin, respectively, enables the determination of abamectin and doramectin in soil. The developed analytical method can be used for monitoring of soil contamination with abamectin and doramectin and also for eco-toxicological studies of avermectins.