Solid-phase microextraction combined with gas chromatography and atomic emission detection for the determination of cyclopentadienylmanganese tricarbonyl and (methylcyclopentadienyl)manganese tricarbonyl in soils and seawaters

A method based on solid-phase microextraction with capillary gas chromatography and microwave-induced plasma atomic emission detection (SPME-GC-MIP-AED) for the determination of cyclopentadienylmanganese tricarbonyl (CMT) and its methyl derivative, (methylcyclopentadienyl)manganese tricarbonyl (MMT) in seawaters and soils was optimized and evaluated. The solvent-free preconcentration step was carried out in the headspace (HS) mode. Element-specific detection and quantification was carried out by monitoring the manganese (259 nm) emission line. A matrix effect was found for the soil samples investigated, so that standard additions were required for their quantification. On the other hand seawaters were analyzed by applying direct calibration against aqueous standards. Detection limits of 13 and 15 pg Mn L(-1) were obtained for CMT and MMT, respectively, in seawaters, and 0.62 and 0.65 pg Mn g(-1), respectively, for the soil samples. The method permitted recoveries of 76-113%, depending on the compound and the sample analyzed, confirming the reliability of the procedure and its suitability for routine monitoring purposes.

Gas chromatographic determination of organomercury following aqueous derivatization with sodium tetraethylborate and sodium tetraphenylborate. Comparative study of gas chromatography coupled with atomic fluorescence spectrometry, atomic emission spectrometry and mass spectrometry

Several hyphenated analytical techniques, including gas chromatography (GC) coupled with atomic fluorescence spectrometry (AFS), microwave-induced plasma atomic emission spectrometry (AES), and mass spectrometry (MS), have been evaluated for methylmercury and ethylmercury analysis following aqueous derivatization with both sodium tetraethylborate and sodium tetraphenylborate. Both GC-AFS and GC-AES were shown to be excellent techniques with detection limits in the range of sub-picogram levels (0.02-0.04 pg as Hg). Both techniques have wide linear ranges, although setting of the AFS sensitivity has to be selected manually based on the concentration of mercury in the sample. Phenylation seems to be more favorable in this study because of its capability of distinguishing between ethylmercury and inorganic mercury, and low cost compared to ethylation. Although sensitivity of GC-MS is poor with detection limits ranging from 30 to 50 pg as Hg, it is an essential technique for confirmation of the derivatization products.