Determination of thallium in sediments of the River Elbe using isotope dilution mass spectrometry with thermal ionization

Abstract

By using isotope dilution mass spectrometry with thermal ionization, TI concentrations were determined in sediments from six sampling positions of the River Elbe in the area of the former GDR (Bad Schandau, Dresden, Barby, Magdeburg, Werben/Havel and Cumlosen). For comparison, two samples from the River Rhine near Emmerich taken in 1978 and 1990 and the Community Bureau of Reference (BCR) certified reference material (CRM) 320 River Sediment were also analysed. Thallium concentrations after complete decomposition by high-pressure digestion (HNO3 + HF) and aqua regia [HCI-HNO3 (3 + 1)] ranged from 537 micrograms kg-1 in the BCR CRM 320 to 5192 micrograms kg-1 in the River Rhine sediment (1978) near Emmerich. The reproducibility of the method ranged from 0.06 to 4.7%. Only 49-94% of the total amount of TI was found after extraction with 1 mol dm-3 HNO3 and 43-86% after extraction with aqua regia. Sediments from Dresden, Barby, Werben/Havel and Cumlosen were found to have virtually identical TI concentrations as the River Rhine sediment sampled in 1990. In comparison with the extremely high Hg and As concentrations found in the River Elbe in an earlier study, the TI concentrations were not as high as expected.

Control of spectral and non-spectral interferences in the determination of thallium in river and marine sediments using solid sampling electrothermal atomic absorption spectrometry

“…For these reasons, an extraction with boiling aqua regia under reflux is frequently preferred over a total digestion. [31][32][33] Such an extraction, however, may be incomplete, as has been shown by Waidmann et al, 34 who reported that only 43-86% of the total amount of thallium present in sediment samples was found after extraction with aqua regia. Although it has been demonstrated that such extracts can be handled by ETAAS, particularly in the presence of permanent chemical modifiers, 35 it was suspected that, in the case of thallium, the aqua regia medium would aggravate the chloride interference problem.…”

Speciation analysis of thallium using electrothermal AAS following on-line pre-concentration in a microcolumn filled with multiwalled carbon nanotubes

“…Thallium can be found in nature as Tl(I) and Tl(III) ions but its monovalent state has higher stability, whereas its trivalent state forms complexes of greater stability. Thus each state of the element exhibits different bioavailability and toxicity properties [3,4]. For this reason, studies not only attempt to determine Tl total concentration, Tl species determination is also important as well [3][4][5].…”

“…Thus each state of the element exhibits different bioavailability and toxicity properties [3,4]. For this reason, studies not only attempt to determine Tl total concentration, Tl species determination is also important as well [3][4][5]. Regarding the toxicity of this metal, its presence, even in small concentrations in natural waters that serve for drinking or irrigation, might be a certain signal of mixing pure water with contaminated wastewater [6].…”

Total digestion of silicate containing matrices (plants, soil, sludges) using a pressure ashing device with PFA-vessels

“…These procedures are highly time consuming depending on the silicate content and dangereous concerning a possible contamination by P. Schramel ( ) · I. Wendler GSF-Research Center for Environment and Health, Institute for Ecological Chemistry Neuherberg, D-85758 Oberschleißheim, Germany G. Knapp Institute for Analytical Chemistry, Micro-and Radiochemistry, Technical University Graz, A-8010 Graz, Austria laboratory air and dust or losses of volatile elements or ligands. Closed systems with PTFE vessels (conventional or microwave assisted heated) have been also used for this task [8][9][10][11][12][13][14][15] but PTFE in these systems, as well as in open system has the big disadvantage of a very porous surface resulting in high memory effects of the sample vessels which may play an essential role in treating subsequently samples with very different concentrations of the analyte elements.…”