Microwave-accelerated speciation analysis for butyltin compounds in sediments and biomaterials by large volume injection capillary gas chromatography quartz furnace atomic absorption spectrometry

Abstract

A method for speciation analysis of butyltins in sediments and biomaterials by capillary GC with atomic absorption spectrometric detection was developed. Mono-, di- and tributyltin in sediments were quantitatively leached with 50% acetic acid, whereas biomaterials were dissolved in a 25% tetramethyl ammonium hydroxide (TMAH) solution; both processes were completed under the action of a low-power focused microwave field within 1–5 min which is 20–100 times faster than with conventional procedures. The butyltins were derivatized with sodium tetraethylborate (NaBEt 4) in the aqueous phase, and simultaneously extracted into hexane (5 min). On-line preconcentration in the injector liner by solvent venting enabled to obtain a detection limit of 5 ng g −1 for 0.2 g of dry sample. A sample throughput of 5 samples h −1 was achieved. The method developed was validated by analyzing three certified reference materials: PACS-1, CRM 462 and NIES 11.