Publication Abstract

The performance characteristics of an analytical method involving a gas chromatography-inductively coupled plasma-mass spectrometry for the measurement of organotin compounds (OTCs) in marine waters have been investigated. The approach permits the determination of six OTCs, including butyl- and phenyl-tins. Good linearity of detection for each OTC was achieved with correlation coefficients >0.99 and a working linear range of detection between 0.1 and 20 µg/L was found. Instrumental limits of detection were excellent and were between 0.05 and 0.1 µg/L. The target analytes spiked in water samples were derivatised with sodium tetraethyl borate and isolated from the aqueous phase by either liquid-liquid or solid phase extraction (SPE). The former approach demonstrated satisfactory recoveries and within the range of 84.5 to 107.5%. However, poor recoveries of the ethylated compounds were obtained during the derivatisation stage. It was one of the objectives of this work to develop a method sensitive enough to detect low levels of OTCs in marine waters. Since this approach showed unacceptable recoveries, the annual mean, Environmental Quality Standard (EQS) currently set under the Water Framework Directive of 0.2 ng/L could not be achieved. Further work is necessary, specifically to investigate the improvement of the derivatisation stage of the OTCs and their isolation from marine waters by SPE.