Monomethylmercury compounds are of great concern, as these highly toxic compounds are formed biotically by microorganisms in sediment and algae in sea water and/or abiotically. Once it is formed, methylmercury is bioaccumulated and biomagnified in the aquatic food chains, thus resulting in exposure levels among fish-eating populations, often at levels exceeding what is regarded as a safe level.
It is therefore of primary interest to have samples from sediments since this is the starting point of the food chain.
The main issues (see the related information below) to be controlled during the analysis of sediments for the speciation analysis of mercury are:
- quantitativeness of extraction of the species from the sediment/soil
- absence of artificial formation of methylmercury during the analytical procedure
- control of contamination mainly for inorganic mercury
- control of the derivatization yield
- avoidance of ion-exchange and adsorption problems on GC column packing materials
CRMs play a major role in the development and validation of
methods and for quality control. The following certified reference
materials (CRMs) are available for the speciation of mercury species in soils and sediments:
Supplier
|
Name
|
Material
|
Certificate
|
| BCR |
CRM 580
|
Estuarine sediment
|
Total and methyl mercury |
IAEA
|
IAEA 405
|
Estuarine sediment
|
Trace metals, mercury and methylmercury |
| IAEA |
IAEA 433
|
Marine sediment
|
Trace metals, mercury and methylmercury |
IRMM
| ERM-CC580
| Estuarine sediment
| Total and methyl mercury |
* () =information value only, []= original certification no longer valid
NB:! click on the material name for a link to the material database giving information on the certificate
Related EVISA Resources
Material Database: Materials related to mercury speciation Material Database: Mercury in sediments Material Database: Mercury in soils Material Database: Mercury standards Material Database: Mercury Isotopic Materials Link Page: All about CRMs Brief summary: Certified reference materials for mercury in marine animal tissues Brief summary: Certified reference materials for mercury in biological materials Brief summary: Certified Reference Materials for Speciation Analysis
Related information Alejandra Delgado, Ailette Prieto, Olatz Zuloaga, Alberto de Diego, Juan Manuel Madariaga,
Production of artifact methylmercury during the analysis of certified reference sediments: Use of ionic exchange in the sample treatment step to minimise the problem, Anal. Chim. Acta, 582 (2007) 109–115.
doi: 10.1016/j.aca.2006.08.051 Martine Leermakers, Willy Baeyens,
Philippe Quevauviller,
Milena Horvat,
Mercury in environmental samples: Speciation, artifacts and validation, Trends Anal. Chem., 24/5 (2005) 383-393:
doi: 10.1016/j.trac.2004.01.001 R. C. Rodríguez Martín-Doimeadios, M. Monperrus, E. Krupp, D. Amouroux,
O.F.X. Donard,
Using Speciated Isotope Dilution with GC-Inductively Coupled Plasma MS To Determine and Unravel the Artificial Formation of Monomethylmercury in Certified Reference Sediments, Anal. Chem., 75 (2003) 3202-3211.
doi: 10.1021/ac026411a Chad R. Hammerschmidt, William F. Fitzgerald,
Formation of Artifact Methylmercury during Extraction from a Sediment Reference Material, Anal. Chem.,73 (2001) 5930-5936.
doi: 10.1021/ac010721w Ph. Quevauviller,
Certification of methylmercury in sediment: from controversial facts to scientific evidence, Chemosphere, 39/7 (1999) 1153-1165.
doi: 10.1016/S0045-6535(99)00184-8 H. Hintelmann,
Comparison of different extraction techniques used for methylmercury analysis with respect to accidental formation of methylmercury during sample preparation, Chemosphere, 39/7 (1999) 1093–1105.
doi: 10.1016/S0045-6535(99)00180-0 Nicolas S. Bloom, John A. Colman, Lee Barber,
Artifact formation of methyl mercury during aqueous distillation and alternative techniques for the extraction of methyl mercury from environmental samples, Fresenius J. Anal. Chem., 385 (1997) 371-377.
doi: 10.1007/s002160050432 H. Hintelmann, R. Falter, G. Ilgen, R.D. Evans,
Determination of artifactual formation of monomethylmercury (CH3Hg+) in environmental samples using stable Hg2+ isotopes with ICP-MS detection: Calculation of contents applying species specific isotope addition, Fresenius J. Anal. Chem., 358 (1997) 363–370.
doi: 10.1007/s002160050431 Milena Horvat,
Nicolas S. Bloom, Lian Liang,
Comparison of distillation with other current isolation methods for the determination of methyl mercury compounds in low level environmental samples. Part 1. Sediments, Anal. Chim. Acta, 281 (1993) 135-152.
doi: 10.1016/0003-2670(93)85348-N
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