Determination of tributyltin and inorganic tin in sea-water by solvent extraction and hydride generation electrothermal atomic absorption spectrometry

Abstract

An ultrasensitive method for the determination of tributyltin and inorganic tin has been developed by in situ concentration of tin hydrides on a zirconium coated graphite tube with subsequent detection by electrothermal atomic absorption spectrometry (ETAAS). Characteristic mass values of 20 and 14 pg were obtained for tributyltin and inorganic tin, respectively, where characteristic mass is defined as that mass of analyte which provides a defined peak absorbance of 0.0044 A. The relative standard deviations for ten replicate measurements were 5.6% for tributyltin and 3.4% for inorganic tin. For speciation studies, tributyltin was extracted in dichloromethane and determined by ETAAS. The sensitivity of tin in organic solution was about the same as that for inorganic tin in aqueous solution. The method proposed was applied to the analysis of water and satisfactory results were obtained.