Determination of volatile mercury species at the picogram level by low-temperature gas chromatography with cold-vapour atomic fluorescence detection

A technique is presented, which allows the rapid and precise determination of methylmercury in aqueous samples. The sample is first reacted with sodium tetraethylborate, to convert the nonvolatile monomethyl mercury to gaseous methylethylmercury. The volatile adduct is then purged from solution, and recollected on a graphitic carbon column at room temperature. The methylethylmercury is then thermally desorbed from the column, and analyzed by cryogenic gas chromatography with cold vapour atomic fluorescence detection. The method allows the simultaneous determination of labile Hg(II) species, through the formation of diethylmercury, and of dimethylmercury, which is not ethylated. The methylmercury detection limit is about 0.6 pg Hg, or 0.003 ng∙L−1 for a 200-mL sample. The technique has been successfully applied directly to a wide variety of freshwater samples and alkaline tissue digestates. Seawater is analyzed following a simple extraction step to separate the methylmercury from the interfering chloride matrix. Analyses of natural surface waters have shown methylmercury levels typically in the range of 0.02–0.10 ng∙L−1, with values as high as 0.64 ng∙L−1 in a polluted urban lake. Waters collected from the anoxic bottom waters of a stratified remote lake have shown methylmercury levels as high as 4 ng∙L−1 as Hg.

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Simultaneous determination of methyl- and ethyl-mercury by solid-phase microextraction followed by gas chromatography atomic fluorescence detection

Journal of Chromatography A ◽

10.1016/j.chroma.2009.10.043 ◽

2009 ◽

Vol 1216 (51) ◽

pp. 8828-8834 ◽

Cited By ~ 28

Author(s):

Luis Carrasco ◽

Sergi Díez ◽

Josep M. Bayona

Keyword(s):

Gas Chromatography ◽

Simultaneous Determination ◽

Fluorescence Detection ◽

Solid Phase Microextraction ◽

Solid Phase ◽

Atomic Fluorescence ◽

Ethyl Mercury

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Liquid chromatographic – cold vapour atomic fluorescence spectrometric determination of mercury species

Journal of Separation Science ◽

10.1002/jssc.200500300 ◽

2006 ◽

Vol 29 (2) ◽

pp. 248-255 ◽

Cited By ~ 26

Author(s):

Pavlína Houserová ◽

David Matějíček ◽

Vlastimil Kubáň ◽

Jana Pavlíčková ◽

Josef Komárek

Keyword(s):

Mercury Species ◽

Atomic Fluorescence ◽

Cold Vapour ◽

Liquid Chromatographic

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Methods development for the determination of methyl mercury in sediment samples using gas chromatography with atomic fluorescence detection

Science and Technology Development Journal ◽

10.32508/stdj.v16i2.1452 ◽

2013 ◽

Vol 16 (2) ◽

pp. 53-60

Author(s):

An Quoc Trieu ◽

Huy Phuong Tran ◽

Dong Van Nguyen

Keyword(s):

Gas Chromatography ◽

Detection Limit ◽

Fluorescence Detection ◽

Potassium Oxalate ◽

Fluorescence Detector ◽

Atomic Fluorescence ◽

Sediment Samples ◽

Methods Development ◽

Instrumental System

An analytical method for methylmercury (MeHg) using gas chromatography with atomic fluorescence detection is studied. The instrumental system is made based on a old gas chromatograph interfaced with an atomic fluorescence detector which is specific to Hg, currently available in our lab. Operating parameters for the GC-AFS system are optimised and analytical performances of the system are verified by quality control chart for stability. MeHg in sediment is leached and extracted to dichloromethane (DCM) in the presence of nitric acid, potassium chloride and copper sulfate. DCM in the extract is purged and MeHg is back extracted to aqueous phase followed by ethylation with sodium tetraethylborate in acetate buffer pH 5.3 containing potassium oxalate. The ethylated MeHg is then extracted to hexane and injected to GC-AFS for quantitation. The instrumental detection limit and method detection limit are 0.5 pg MeHg and 0.029 ppb MeHg (as Hg), respectively. The method can be applied for the determination of MeHg in soil, sludge and sediment samples.

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