Mercury determination and speciation analysis in surface waters

• Published in: Central European Journal of Chemistry 2012-08, Vol.10 (4), p.1175-1182
• Main Authors: Mladenova, Elisaveta K., Dakova, Ivanka G., Tsalev, Dimiter L., Karadjova, Irina B.
• Format: Article
• Language: English
• Subjects: Biochemistry; Biological and Medical Physics; Biophysics; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Dissolution; Enrichment; Extraction; Geochemistry; L-cysteine modified sorbent; Mercury; Mercury speciation; Research Article; Separation; Sorbents; Standard deviation; Surface water; Surface water analysis
• ISSN: 1895-1066; 2391-5420; 1644-3624; 2391-5420
• DOI: 10.2478/s11532-012-0027-0

A sorbent L-cysteine grafted silica gel has been evaluated for separation and enrichment of dissolved inorganic i-Hg(II) and methylmercury CH 3 Hg(I) from surface waters at sub-µg L −1 concentrations. Chemical parameters for mercury species enrichment and separation have been optimized. Analytical schemes for the determination of Hg species, using selective column solid phase extraction (SPE) with continuous flow chemical vapor generation atomic absorption spectrometry (CF-CVG-AAS) or inductively coupled plasma-mass spectrometry (ICP-MS) were developed. Possibilities for on-site SPE enrichment were demonstrated as well. The limits of quantification were 1.5 and 5 ng L −1 for dissolved i-Hg(II) and CH 3 Hg(I) by CF-CVG-AAS and 1 and 2.5 ng L −1 by ICP-MS with relative standard deviations between 7–12% and 7–14%, respectively. The chemically modified SPE sorbent has demonstrated high regeneration ability, chemical and mechanical stability, acceptable capacity and good enrichment factors. Results for total dissolved mercury were in reasonable agreement with those from independent analyses by direct ICP-MS determinations for river waters and for estuarine water certified reference material.