Butyltin Compounds In Sediments Research Articles

Determination of Butyltin Compounds in Sediments by Means of Hydride Generation/Cold Trapping Gas Chromatography Coupled to Inductively Coupled Plasma Mass Spectrometric Detection

Determination of Butyltin Compounds in Sediments by Means of Hydride Generation/Cold Trapping Gas Chromatography Coupled to Inductively Coupled Plasma Mass Spectrometric Detection

Determination of Butyltin Compounds in Sediments by GC/MS After Their Conversion to Methyl Derivatives

A selective and rapid procedure was developed for the determination of trace amounts of butyltin compounds in sediments by capillary gas chromatography with mass spectrometric detection. Analytes were isolated from the sediment samples by extraction with a methanolic solution of HCl (0.5 mol l-1) followed by reextraction into a hexane solution of tropolone (0.1%). The organotin compounds were converted to the nonpolar methyl derivatives by methylation with a Grignard reagent. The recovery was determined for each step of the procedure. This efficient separation method combined with the ion trap based mass detection ensures a high selectivity even for concentrations approaching the detection limit (0.15 pg for Bu3SnMe) in real sediments. Chemical ionization using acetonitrile as the reaction gas, exhibiting a similar sensitivity of determination and reducing the background level, can serve as a convenient alternative of detection for sediments heavily contaminated by organics. The method was applied to a set of real samples and validated by analysis of a certified reference material.

Microwave-accelerated speciation analysis for butyltin compounds in sediments and biomaterials by large volume injection capillary gas chromatography quartz furnace atomic absorption spectrometry

A method for speciation analysis of butyltins in sediments and biomaterials by capillary GC with atomic absorption spectrometric detection was developed. Mono-, di- and tributyltin in sediments were quantitatively leached with 50% acetic acid, whereas biomaterials were dissolved in a 25% tetramethyl ammonium hydroxide (TMAH) solution; both processes were completed under the action of a low-power focused microwave field within 1–5 min which is 20–100 times faster than with conventional procedures. The butyltins were derivatized with sodium tetraethylborate (NaBEt 4) in the aqueous phase, and simultaneously extracted into hexane (5 min). On-line preconcentration in the injector liner by solvent venting enabled to obtain a detection limit of 5 ng g −1 for 0.2 g of dry sample. A sample throughput of 5 samples h −1 was achieved. The method developed was validated by analyzing three certified reference materials: PACS-1, CRM 462 and NIES 11.

Rapid speciation of butyltin compounds in sediments and biomaterials by capillary gas chromatography-microwave-induced plasma atomic emission spectrometry after microwave-assisted leaching/digestion

A rapid procedure for the simultaneous determination of mono-, di- and tributyltin in sediments and biological materials is described. The target compounds in sediments were subject to quantitative microwave-assisted leaching with acetic acid. Biomaterials were dissolved in a tetramethylammonium hydroxide solution under the action of a low-power microwave field in such a way that the organotin moiety remained intact. The leaching of the analytes from a sediment as well as the dissolution of a biomaterial in a focused microwave field took only 1–5 min, which is much faster than previously reported methods. It was also demonstrated that the leaching efficiency of monobutyltin from certified reference sediments was superior to that of most literature procedures. The butyltins were derivatized with sodium tetraethylborate (NaBEt4) in the aqueous phase, and simultaneously extracted into isooctane (5 min). The analysis was carried out by capillary gas chromatography (GC) with microwave-induced plasma atomic emission detection. The sample throughput was limited by the duration of the GC run (10 min). The detection limit was 2 ng g–1 for 0.2 g of sample (dry) without preconcentration; it could be improved by a factor 10 if preconcentration was applied. The developed method was applied to a variety of real samples and was validated by analysing three certified reference materials: PACS-1, CRM 462 and NIES 11.

Speciation of butyltin compounds in sediments using gas chromatography interfaced with quartz furnace atomic absorption spectrometry

A method is presented for the determination of tri- and dibutyltin in sediments by gas chromatography—quartz furnace atomic absorption spectrometry. The compounds are released from the matrix by the action of acetic acid and extracted into hexane after formation of an extractable complex with diethyldithiocarbamic acid (DDTC). Pentylmagnesium bromide is used to derivatize the non-volatile organotin—carbamate complexes. A detection limit of 2.5 ng/g (as Sn) can be achieved. The optimization of the different parameters is discussed and the accuracy of the method was validated by the analysis of two certified reference materials. A first approach was made to determine tri- and dimethyltin compounds forming extractable complexes with NaDDTC under pH controlled conditions.

Determination of butyltin compounds in sediments using an improved aqueous ethylation method

We have determined tributyltin and dibutyltin species in various environmental sediment samples (marine, harbour and river sediment) using the in situ aqueous ethylation—gas chromatography—atomic absorption spectrometry method subsequent to extraction by methanol containing O.5 M HCl. The present technique provides a significantly lower detection limit than previous methods, so that tributyltin can for the first time be measured in some of the samples. Thus, the method described is well suited for the determination of tributyltin and dibutyltin compounds in sediments with low levels of butyltin species ( e.g., Main River, 1.7 ng of tributyltin as Sn/g dry sediment).

Projects for the improvement of the quality of chemical speciation analyses in environmental matrices

The release of organometallic compounds and other chemical forms of elements in the environment has caused great concern because of their possible high toxicity. To validate the analytical techniques, the Community Bureau of Reference (BCR) has undertaken a series of projects for the improvement of the quality of determinations of chemical species in environmental matrices. The implementation of these projects follows a stepwise approach involving intercomparisons to detect and remove sources of errors in different phases of the analytical methods and the certification of the compounds in various matrices. The current projects deal with the determination of the extractable content of trace metals in soils (single extraction) and sediment (sequential extraction), forms of aluminium in water, elements with different oxidation states (e.g. As, Cr and Se) and organic forms (e.g. methylated forms of As in solution, methyl-mercury in fish, arseno-betaine and -choline in solutions, triethyl- and trimethyl-Pb compounds in solution, and butyltin compounds in sediment).

Evaluation of extraction techniques for butyltin compounds in sediment

AbstractThere have been many methods available for the determination of butyltin compounds in sediment. The variations of these methods are not in the methods of determination but rather in the extraction of these compounds from the complex matrices. All of these methods have not been critically compared or evaluated, mainly because of the lack of a suitable reference sediment for butyltin compounds.Recently, the National Research Council of Canada has introduced a reference sediment (PACS‐1) which contains certified values of butyltin compounds. The present study compares the recoveries of ten extraction techniques for butyltin species using ethylation derivatization and GC AA as the method of determination. Of these ten methods, only four were found satisfactory for extraction of the dibutyltin and tributyltin species. None of the methods evaluated, however, could quantitatively extract monobutyltin from sediment.

Determination of inorganic tin, methyltin, and butyltin compounds in sediments

Abstract A simple method is described for the determination of inorganic tin, methyl‐, and butyltin compounds in sediments. Freeze‐dried samples were extracted with a solution containing 2.5 M calcium chloride and 2.5 M hydrochloric acid. The extracts were analyzed by hydride generation‐atomic absorption spectrometry. Recoveries from spiking experiments were greater than 70 ± 10% for most of the alkyltin compounds. Results from Great Bay Estuary (New Hampshire) sediment samples are presented.