Determination of organotin compounds by liquid chromatography-inductively coupled plasma mass spectrometry with a direct injection nebulizer

Inductively coupled plasma mass spectrometry (ICP-MS) coupled with direct injection nebulization was used as a liquid chromatographic detection method for the determination of butyltin compounds. Mono-, di- and tributyltin were separated by reversed phase liquid chromatography with 5 mM sodium 1-pentanesulfonate and 0.1% tropolone as the ion pairing reagent and 80% methanol and 2% acetic acid as the organic modifier. The separation was complete in less than 4 min. Detection limits were in the range 1.8-2.5 pg Sn for various tin compounds. The relative standard deviation of the peak areas for five injections of 10 ng ml(-1) organotin mixture was in the range 5-8%. This method was applied to the determination of various butyltin compounds in harbour sediment reference sample PACS-2 and a sediment sample collected from the Taiwan Strait. A simple and rapid microwave-assisted extraction method was used for the extraction of organotin compounds from marine sediments. The analyte species were leached quantitatively with acetic acid and sodium 1-pentanesulfonate in a focused microwave held during a period of 3 min.