W. M. R. Dirkx

Speciation analysis of organotin in water and sediments by gas chromatography with optical spectrometric detection after extraction separation

Abstract The state of the art of gas chromatography with atomic emission and atomic absorption spectrometric detection as a technique for speciation analysis of organotin in water samples and sediments is discussed. Extraction separation of ionic organotin compounds and their conversion to gas chromatographable species are reviewed. Recent advances in instrumentation with respect to sensitivity, selectivity and applicability to real sample analysis are highlighted. Particular emphasis is given to sources of error and accuracy of the data obtained.

Rapid sensitive speciation analysis of butyl- and phenyltin compounds in water by capillary gas chromatography atomic emission spectrometry (GC-AES) after in-situ ethylation and in-liner preconcentration

SummaryA rapid, simple and sensitive method has been developed for the simultaneous determination of butyl- and phenyltin species in environmental waters. The ionic organotin compounds are ethylated in the aqueous phase using sodium tetraethylborate (NaBEt4) and extracted with hexane. A 25 μl aliquot of the extract is injected at a low temperature into a Tenax filled liner. After solvent venting the analytes are transferred onto the capillary column using programmed temperature vaporization (PTV) injection. Detection is done by means of a microwave induced plasma atomic emission detector (MIP AED). The method allows the determination of butyl- and phenyltin compounds in water samples down to the level of 0.1 ng/l (as Sn) while 50 ml of sample is sufficient for analysis. The accuracy of the method was confirmed by GC-AAS after chelation and Grignard derivatization.

Speciation of organotin compounds in water by gas chromatography/atomic absorption spectrometry

SummaryA reproducible and interference-free method is presented for simultaneous determination of individual tri-, di- and monoalkyltin species present in aqueous systems. The ionic methyltin and butyltin compounds are extracted from water into pentane as diethyldithiocarbamate complexes at pH 5. The organic phase is then evaporated to dryness under reduced pressure, after which derivatization withn-pentyl (Pe) Grignard reagent is carried out in a microvolume ofn-octane to form pentylated alkyltin compounds RnSnPe(4-n) (R = Methyl, Me or Butyl, Bu). The quantitation is subsequently performed by gas chromatography with quartz furnace atomic absorption spectrometric detection (GC-AAS). Absolute detection limits range between 0.16 ng and 0.40 ng Sn for the various organotin species, allowing speciation in natural water down to the 4-10 ng ⁗ 1−1 level.

Speciation analysis of organolead compounds by gas chromatography with atomic spectrometric detection

Abstract The state of the art of hyphenated techniques involving gas chromatography applied to speciation analysis of organolead is presented. Recent developments in the field of injection techniques, gas chromatographic separation, interface design and detection are discussed. An overview of procedures applicable to the analysis of water samples, sediments and biological materials is given. Particular attention is given to the factors affecting the accuracy of analysis.

Preliminary Study on Degradation of Ionic Alkyllead Species in Water

Abstract Laboratory experiments are reported, aimed at monitoring the degradation of ionic alkyllead compounds in water in the dark, in daylight and with UV irradiation. A stepwise dealkylation in aqueous media is not supported by the simulations. It appears that trialkyllead (triAL) degradation does not give rise to appreciable formation of dialkyllead (diAL) but directly yields inorganic lead; on the other hand, dialkyllead species appear too stable to be involved as short-lived intermediates. Generally ethyllead compounds are observed to be more sensitive towards degradation than the corresponding methyllead compounds. The results are consistent with existing literature evidence.

Speciation Analysis Of Organotin In The River Scheldt By Capillary Gas Chromatography Atomic Emission Spectrometry (Gc-Aes)

Abstract Two rapid, sensitive and interference-free analytical procedures were developed for the comprehensive speciation analysis of ionic butyl- and phenyltin compounds in water. One of them based on ethylation of ionic organotin in the aqueous phase with sodium tetraethylborate (NaBEt4) followed by the extraction of the derivatized species into hexane. The other method involved preconcentration of ionic organotin on a C18 cartridge followed by on-column ethylation in a semi-automated flow system. Separation and determination of organotin species were performed by capillary gas chromatography with microwave induced plasma atomic emission detection (GC-MIP AED). 20–50 ml of sample was sufficient for the analysis and a detection limit of 0.1 ng/l (as Sn) was obtained. The methods were applied to the determination of organotin in the river Scheldt at 15 locations close to the Antwerp agglomeration. Butyltin compounds were detected in all the analyzed samples at concentrations ranging between 10–140 ng/l, 8...

Speciation of ionic alkyllead in potable water and soil

Various potable water and soil samples have been analyzed for tri- and dialkyllead compounds using a sensitive speciation procedure based on diethyldithiocarbamate extraction, Grignard derivatization and gas chromatography-atomic absorption spectrometry. The species are generally present as ultra-trace contaminants, and their abundance is critically discussed. In addition, a degradation study of ionic alkyllead in ambient matrices is presented.

Determination of methyl- and butylin compounds in waters of the Antwerp harbour

Abstract Ionic methyltin and butylin compounds were determined in dockwater of the harbour of Antwerp (Belgium) in order to evaluate the emission and distribution of organotin species discharged during dry dock activities. Speciation analysis was performed by gas chromatography-quartz furnace atomic absorption spectrometry (GC-QFAAS) and gas chromatography with atomic emission detection (GC-AED) after enrichment by extraction of the analytes as the corresponding diethyldithiocarbamate (DDTC) complexes into pentane and pentylation of the extracted analytes with Grignard reagent. Concentrations of dimethyltin (DMT), monomethyltin (MMT), tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT), varied between 0.74 and 5; 0.88 and 10; 1.83 and 443; 1.45 and 120; 1.08 and 38 ng·l−1 at various locations and sampling times in the harbour docks of Antwerp, the highest concentrations of TBT being found near a vessel repair facility. In one of the harbour docks, the concentrations of butyltins increased from May until August due to the discharge of tributyltin in hosing-down water and the launching of freshly painted sea-going vessels.

Interferences in ultratrace speciation of organolead and organotin by gas chromatography with atomic spectrometric detection

Interferences in trace and ultratrace speciation analysis of organotin and organolead compounds in various samples by gas chromatography coupled with atomic absorption spectrometry (AAS) and/or microwave induced plasma atomic emission spectrometry (MIP AES) are investigated. Particular attention is given to the effects of matrix co-extractives and reagents impurities introduced during sample preparation. Their influence on the detection limits is discussed in terms of baseline noise level, blank value, formation of artefacts and signal suppression. Loss of column resolution during the analysis of some matrices is observed.

Speciation of alkyllead compounds by GC-AAS: A state of affairs

A synopsis of the organolead studies performed at our University is given. The different environmental applications such as air, wet atmospheric deposition and dust are summarized and the analytical characteristics of the extraction/derivatization/gas chromatography—atomic absorption spectrometry methodology for the species specific determination of ionic alkyllead species are described.