Quantitative analysis of ethyltin compounds in mammalian tissue using HPLC/FAAS

Measurement of total tin and ethyln tin forms in mammalian tissue is described, using ion-exchange high performance liquid chromatography (HPLC) in tandem with flameless atomic absorption spectrometry (FAAS) for tin-specific detection. All tin forms in whole blood and tissue homogenates were liberated from biological (in vivo) binding by treatment with 6M hydrochloric acid for a period of 4 hr. Ethyln tin species, as the chlorides, were partitioned into chloroform:ethyl acetate (1:1) and analyzed via HPLC using a strong cation exchange column, with fraction collection by a programmable collector and fraction tin measurement by FAAS. Triethyl- and diethyltin were separated and quantitated using 0.167M ammonium citrate in 70:30 methanol:water, while monoethyltin required the use of 0.50M citrate salt in 70:30 water:methanol as mobile phase to effect elution. The difference between total and speciated tin content provides an estimate of remaining tin species, including the inorganic element.