Determination of Leachable Vanadium (V) in Sediment

A method for speciation of vanadium in solid samples was developed for quantification of vanadium(+5) in solid samples of sediment Certified Reference Materials (CRM) PACS-2 and MESS-3 (Trace Elements in Sediments) of known total vanadium content. The method relies on a classical analytical chemistry procedure based on leaching water-insoluble vanadium(+5) compounds fromthe solid state into solution using Na2CO3 followed by electrothermal atomic absorption spectrometry (ET-AAS) detection. The total amount content of vanadium was determined after complete digestion of the CRMs and found to be 132 ± 5 and 245 ± 12 μg g–1 in PACS-2 and MESS-3, respectively, in good agreement with the certified values of 133 ± 6 μg g–1 and 243 ± 12 μg g–1. The concentrations of vanadium(+5) were determined to be 25 ± 3 μg g–1 and 13 ± 2 μg g–1 in PACS-2 and MESS-3, respectively. These results were verified by the method of standard additions for which quantitative recoveries (100 ± 2 and 97 ± 3 %, one standard deviation, n = 3) were obtained for spikes added to PACS-2 and MESS-3, respectively. Approximately 18.8 % of the total vanadium content of PACS-2 and 5.3 % in MESS-3 is in the form of vanadium(+5) species.KEYWORDS Certified reference materials, vanadium(+5) speciation, electrothermal atomic absorption spectrometry

The application of tree bark as bio-indicator for the assessment of Cr(VI) in air pollution

The impact of a chromium smelter on pollution was evaluated by determining Cr(VI) in topsoil, grass and tree bark by electhrothermal atomic absorption spectrometry (ETAAS). It was found that bark reflected the levels of air pollution better than soil and grass due to its high accumulative ability of Cr(VI). The tree bark was contaminated with Cr(VI) by a factor of 9 than in soil. It is therefore suggested that the bark be used as an indicator of air pollution for long-term exposure. The concentration of Cr(VI) in the bark was always a fraction of the total concentration of Cr and ranges between 1.6 and 3%. The method used in the preparation of samples was validated by the analysis of certified reference materials