Phenyl- and butyltin analysis in small biological samples by cold methanolic digestion and GC/MS

Avery efficient technique for the analysis of six butyl- and phenyltin comp ounds in biota samples has been developed. No special equipment is needed f or sample preparation, which is based on cold methanolic digestion with sub sequent aqueous ethylation and liquid-liquid extraction, For samples of onl y 40 mg of biological materials, method detection limits ranging from 4 to 52 ng/g were achieved using gas chromatography/mass spectrometry. Relative recoveries for the individual butyl- and phenyltins, referring to perdeuter ated organotin analogues as internal standards, ranged from 96 to 107%. Org anotin concentrations in insect larvae (Chironomus riparius) and a referenc e mussel tissue (CRM 477) were determined with excellent precision (RSD <5% ), and the measured butyltins in CRM 477 were in good agreement with the ce rtified values. Comparison with accelerated solvent extraction confirmed hi gh accuracy, and application for a bioconcentration experiment with phenylt ins demonstrated the robustness and suitability of the method for routine a nalyses. The procedure allows fast, reliable, and simple determination of o rganotin compounds in low-size biological samples, which was demonstrated f or bioconcentration experiments.