Development of an analytical method to determine avermectins in water, sediments and soils using liquid chromatography-tandem mass spectrometry.

A comprehensive analytical multi-residue method has been developed for the determination of seven avermectins (abamectin, doramectin, ivermectin, emamectin benzoate, eprinomectin, moxidectin and selamectin) in surface water, sediment and soil samples. Solid samples were extracted applying pressurised liquid extraction followed by a solid-phase extraction (SPE) clean-up step. For aqueous samples, extraction was done utilising only SPE. All compounds were measured using liquid chromatography coupled to tandem mass spectrometry using atmospheric pressure chemical ionisation. The recoveries were 38-67% (relative standard deviation: 9-26%), 63-88% (16-23%) and 63-80% (9-15%) for spiked Rhine water, spiked sediment and spiked soil samples, respectively, and limit of quantifications were 2.5-14 ngl(-1) in water and 0.5-2.5 ngg(-1) in soil and sediment.