A new study now confirms the presence of ethylmercury in soil of the Florida Everglades probably as the result of bioalkylation.
Background:While methylmercury is a well known mercury species especially occuring in the aquatic environment resulting from microbial biomethylation of inorganic mercury, other organomercurials are mostly directly release from industrial processes or products. A few studies have reported the occurrence of monoethylmercury (
CH3CH2Hg+) in the natural environment, but further verification is needed due to the lack of direct evidence and/or uncertainty in analytical procedures for mercury speciation analysis. Most often,
CH3CH2Hg+ was identified according to its retention time on either GC or HPLC columns only. However, it has been shown that it is possible that other compounds bearing the same retention times with
CH3CH2Hg+ under the same experimental conditions would have been wrongly recognized as
CH3CH2Hg+. For example, it was found that one sulfur-containing species,
CH3SHg+, showed the same retention time as
CH3CH2Hg+ standard when an HPLC-inductively coupled plasma mass spectrometry (ICPMS) method was used for mercury speciation analysis. Other problems occur, when the analytical technique lacks in selectivity, as in the case of GC-ECD detection.
The new study:
Photo: Everglades
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A group of chinese researchers now have used various analytical techniques to verify the occurrence of
CH3CH2Hg+ in soil of the Florida Everglades. The combined use of aqueous phenylation-purge-and-trap-GC-ICPMS, HPLC-AFS and in particular GC/MS which is able to provide the molecular and structural information, confirmed the identity of
CH3CH2Hg+. Additionaly, stable isotope tracer experiments were conducted to exclude the possibility of artifact formation of
CH3CH2Hg+ during sample preparation and/or analytical processes. In the Everglades soil analyzed in this study,
CH3CH2Hg+ and
CH3Hg+ accounted for 0.10–1.30 and 0.26–1.27% of the total mercury concentrations respectively. According to the authors, the similarity between levels of
CH3CH2Hg+ and
CH3Hg+ reveals that ethylation of Hg could be an important transformation pathway of Hg.
The cited study
Yuxiang Mao, Yongguang Yin, Yanbin Li, Guangliang Liu, Xinbin Feng, Guibin Jiang, Yong Cai,
Occurrence of monoethylmercury in the Florida Everglades: Identification and verification, Environ. Pollution, 158/11 (2010) 3378-3384.
doi:10.1016/j.envpol.2010.07.031 Related Studies Yong-guang Yin, Ming Chen, Jin-feng Peng, Jing-fu Liu, Gui-bin Jiang,
Dithizone-functionalized solid phase extraction–displacement elution-high performance liquid chromatography–inductively coupled plasma mass spectrometry for mercury speciation in water samples, Talanta, 81/4-5 (2010) 1788-1792.
doi:10.1016/j.talanta.2010.03.039 Yong-guang Yin, Jing-fu Liu, Bin He, Jian-bo Shi and Gui-bin Jiang,
Mercury speciation by a high performance liquid chromatography—atomic fluorescence spectrometry hyphenated system with photo-induced chemical vapour generation reagent in the mobile phase, Microchim. Acta, 167/3-4 (2009) 289-295,
DOI: 10.1007/s00604-009-0250-3 Yong-guang Yin, Zhen-hua Wang, Jin-feng Peng, Jing-fu Liu, Bin He and Gui-bin Jiang,
Direct chemical vapour generation-flame atomization as interface of high performance liquid chromatography-atomic fluorescence spectrometry for speciation of mercury without using post-column digestion, J. Anal. At. Spectrom., 24 (2009) 1575-1578.
DOI: 10.1039/B907169E José Soares dos Santos, Miguel de la Guárdia, Augustin Pastor, Maria Lúcia Pires dos Santos,
Determination of organic and inorganic mercury species in water and sediment samples by HPLC on-line coupled with ICP-MS, Talanta, 80/1 (2009) 207-211.
doi:10.1016/j.talanta.2009.06.053 Francisco Pena-Pereira, Isela Lavilla, Carlos Bendicho, Lorena Vidal, Antonio Canals,
Speciation of mercury by ionic liquid-based single-drop microextraction combined with high-performance liquid chromatography-photodiode array detection, Talanta, 78/2 (2009) 537-541.
doi:10.1016/j.talanta.2008.12.003
Jianguo Chen, Hengwu Chen, Xianzhong Jin, Haiting Chen,
Determination of ultra-trace amount methyl-, phenyl- and inorganic mercury in environmental and biological samples by liquid chromatography with inductively coupled plasma mass spectrometry after cloud point extraction preconcentration, Talanta, 77/4 (2009) 1381-1387.
doi: 10.1016/j.talanta.2008.09.021 N. Issaro, C. Abi-Ghanem, A. Bermond,
Fractionation studies of mercury in soils and sediments: A review of the chemical reagents used for mercury extraction, Anal. Chim. Acta, 631/1 (2009) 1-12.
doi:10.1016/j.aca.2008.10.020
Yuxiang Mao,Guangliang Liu, George Meichel, Yong Cai, Guibin Jiang,
Simultaneous Speciation of Monomethylmercury and Monoethylmercury by Aqueous Phenylation and Purge-and-Trap Preconcentration Followed by Atomic Spectrometry Detection, Anal. Chem., 80 (2008) 7163–7168.
doi: 10.1021/ac800908b Bin He, Erle Gao, Jianbo Shi, Lina Liang, Yongguang Yin, Guibin Jiang,
Optimization of Pretreatment Method for Alkylmercuries Speciation in Coal by High-Performance Liquid Chromatography Coupled with UV-Digestion Cold Vapor Atomic Fluorescence Spectrometry, Spectroscopy Letters, 39 (2006) 785–796.
DOI: 10.1080/00387010600969945 Jen-How Huang,
Artifact formation of methyl- and ethyl-mercury compounds from inorganic mercury during derivatization using sodium tetra(n-propyl)borate, Anal. Chim. Acta, 532 (2005) 113–120.
doi:10.1016/j.aca.2004.10.057 J. Munoz, M. Gallego, M. Valcarcel,
Solid-phase extraction–gas chromatography–mass spectrometry using a fullerene sorbent for the determination of inorganic mercury(II), methylmercury(I) and ethylmercury(I) in surface waters at sub-ng/ml levels, Journal of Chromatography A, 1055 (2004) 185–190.
doi: 10.1016/j.chroma.2004.09.026 R.-D. Wilken, F. Nitschke, R. Falter,
Possible interferences of mercury sulfur compounds with ethylated and methylated mercury species using HPLC-ICP-MS, Anal. Bioanal. Chem., 377 (2003)149–153.
DOI 10.1007/s00216-003-2090-z Maximilian Hempel, Jürgen Kuballa, Eckard Jantzen,
Discovery of a transalkylation mechanism – Identification of ethylmercury+ at a tetraethyllead-contaminated site using sodiumtetrapropylborate, GC-AED and HPLC-AFS, Fresenius J. Anal. Chem., 366 (2000) 470–475.
DOI: 10.1007/s002160050095 Yong Cai, Rudolf Jaffe, Ronald Jones,
Ethylmercury in the Soils and Sediments of the Florida Everglades, Environ. Sci. Technol., 31/1 (1997) 302-305.
doi: 10.1021/es960587a Holger Hintelmann, Maximilian Hempel, Rolf-Dieter Wilken,
Observation of Unusual Organic Mercury Species in Soils and Sediments of Industrially Contaminated Sites, Environ. Sci. Technol., 29 (1995) 1845-1850.
DOI: 10.1021/es00007a023 Azaam Alli, Rudolf Jaffé, Ronald Jones,
Analysis of organomercury compounds in sediments by capillary GC with atomic fluorescence detection, J. High Resolution Chromatogr., 17/11 (1994) 745–748.
DOI: 10.1002/jhrc.1240171102 H. Hintelmann, R.-D. Wilken,
The analysis of organic mercury compounds using liquid chromatography with on-line atomic fluorescence spectrometric detection, Appl. Organomet. Chem., 7/3 (1993) 173–180.
DOI: 10.1002/aoc.590070303 Edison Munaf, Hiroki Haraguchi, Daido Ishii, Toyohide Takeuchi, Masashi Goto,
Speciation of mercury compounds in waste water by microcolumn liquid chromatography using a preconcentration column with cold-vapour atomic absorption spectrometric detection, Anal. Chim. Acta, 235 (1990) 399-404.
doi:10.1016/S0003-2670(00)82099-1 L. Magos, A. W. Brown, S. Sparrow, E. Bailey, R. T. Snowden and W. R. Skipp,
The comparative toxicology of ethyl- and methylmercury, Arch. Toxicol., 57/4 (1985) 260-267,
DOI: 10.1007/BF00324789 Sumie Yamanaka, Kiichi Ueda,
High ethylmercury in river fish by man-made pollution, Bull. Environ. Contam. Toxicol., 14/4 (1975) 409-414.
DOI: 10.1007/BF01705505 
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last time modified: September 18, 2010
