Speciation of organotins in environmental samples by SPME-GC: Comparison of four specific detectors: FPD, PFPD, MIP-AES and ICP-MS
Résumé
The performances of four specific detectors used for the speciation of butyl- and phenyltin compounds after solid phase microextraction (SPME) and gas chromatography (GC) separation are evaluated. A flame photometric detector (FPD), a pulsed flame photometric detector (PFPD), a microwave induced plasma atomic emission spectrometer (MIP-AES) and an inductively coupled plasma mass spectrometer (ICP-MS) were used. The principle of PFPD, a new generation of FPD, is presented. The original transfer line used between GC and ICP-MS is detailed. The high SPME preconcentration allows very low limits of detection (LOD) to be reached (less than 500 pg 1-1 Sn for all the detectors). Sensitivity, linearity and selectivity of the different detectors are also discussed. As expected, ICP-MS is the most sensitive (LOD ranged from 0.6 to 20 pg 1-1 Sn) but the cheapest PFPD is also of significant interest. The analytical procedure is applied to the determination of organotins in two different reference materials: a sediment (PACS 2) and a fish tissue (NIES 11). These different examples show that the detection of ultra-trace tin species is now possible in natural samples using a combination of SPME and GC with a specific detector.