Speciation of butyltin compounds in marine sediments by preconcentration on C 60 and gas chromatography–mass spectrometry

Abstract

A new method for the speciation of butyltin compounds by solid phase extraction and direct injection using gas chromatography–mass spectrometry (GC/MS) is described. The compounds were complexed with sodium diethyldithiocarbamate and retained on a C 60 sorbent column. The neutral chelates of butyltin compounds were eluted with ethyl acetate containing NaBPr 4 as derivatising reagent. The main analytical figures of merit of the proposed method for 10 ml of sample are: linear range 0.2–35 ng/g expressed as Sn; limits of detection, 0.07, 0.09 and 0.10 ng/g as Sn for monobutyltin, dibutyltin and tributyltin, respectively. No interferences from metal ions such as Zn 2+, Fe 3+, Sb 3+, Pb 2+, Ni 2+ and Mn 2+ were observed in the determination of organotin compounds. The validation of method was performed out by the analysis of a standard reference sediment (CRM 462). The method was also applied to the determination of butyltin compounds in marine sediment samples.