Re‐evaluation of distillation and comparison with HNO3 leaching/solvent extraction for isolation of methylmercury compounds from sediment/soil samples
- 21 May 2004
- journal article
- speciation analysis-and-environment
- Published by Wiley in Applied Organometallic Chemistry
- Vol. 18 (6) , 264-270
- https://doi.org/10.1002/aoc.617
Abstract
Distillation was re‐evaluated for the formation of artifacts arising from increasing naturally occurring mercury(II) concentrations, as opposed to previous identification of artifacts by spiking standard mercury(II) into samples. Naturally occurring mercury(II) concentrations lower than 2 µg g−1 were found not to affect methylmercury (MeHg) results. However, when the natural concentrations of mercury(II) were greater than 2 µg g−1, in contrast to standard mercury(II) spiked in samples, the MeHg concentrations measured were found to decrease (not increase) with increasing naturally occurring mercury(II) concentrations. This indicated that standard mercury(II) spiked in samples behaved differently from naturally occurring mercury(II) in the formation of MeHg artifacts during distillation. As a result, spiking standard mercury(II) into samples to identify the formation of MeHg artifacts is not adequate. It is difficult to explain why high naturally occurring mercury(II) suppresses MeHg measurements during distillation. In comparison with HNO3 leaching/solvent extraction (and other existing techniques), distillation was found to generate results comparable for samples containing less than 2 µg g−1 mercury(II). The HNO3 leaching/solvent extraction showed significant advantages over other procedures, as this technique generated the highest recoveries with good precision for all samples analyzed, and the results were found to be independent of mercury(II) concentrations for both naturally occurring and spiked standard mercury(II). Thus, except for samples from high mercury‐contaminated fields, distillation is still a good choice. Both the positive bias (possibly caused by artifact formation of MeHg) and the negative bias (due to incomplete leaching, back‐adsorption, and/or decomposition of MeHg) were investigated. Geologically, physically, and chemically different samples were used for the investigation. Copyright © 2004 John Wiley & Sons, Ltd.Keywords
This publication has 12 references indexed in Scilit:
- Comparison of distillation with other current isolation methods for the determination of methyl mercury compounds in low level environmental samples: Part 1. SedimentsPublished by Elsevier ,2001
- Artifact formation of methyl mercury during aqueous distillation and alternative techniques for the extraction of methyl mercury from environmental samplesAnalytical and Bioanalytical Chemistry, 1997
- Determination of artifactual formation of monomethylmercury (CH 3 Hg + ) in environmental samples using stable Hg 2+ isotopes with ICP-MS detection: Calculation of contents applying species specific isotope additionAnalytical and Bioanalytical Chemistry, 1997
- Rapid and Quantitative Microwave-assisted Recovery of Methylmercury From Standard Reference SedimentsJournal of Analytical Atomic Spectrometry, 1997
- Simple solvent extraction technique for elimination of matrix interferences in the determination of methylmercury in environmental and biological samples by ethylation-gas chromatography-cold vapor atomic fluorescence spectrometryTalanta, 1996
- Results of the international aqueous mercury speciation intercomparison exerciseWater, Air, & Soil Pollution, 1995
- Working Methods Paper: Certification of methylmercury compounds concentration in marine sediment reference material, IAEA-356Applied Organometallic Chemistry, 1994
- An improved speciation method for mercury by GC/CVAFS after aqueous phase ethylation and room temperature precollectionTalanta, 1994
- Determination of total mercury by single-stage gold amalgamation with cold vapour atomic spectrometric detectionJournal of Analytical Atomic Spectrometry, 1993
- Determination of Picogram Levels of Methylmercury by Aqueous Phase Ethylation, Followed by Cryogenic Gas Chromatography with Cold Vapour Atomic Fluorescence DetectionCanadian Journal of Fisheries and Aquatic Sciences, 1989