Micro-scale preparation of isotopically enriched monomethylmercury (MM201Hg)‎

Abstract EN

A simple and fast synthesis method for the micro-scale laboratory preparation of isotopically enriched monomethylmercury (MMHg) which is not commercially available has been evaluated and established successfully.

This enriched solution is an important standard for species-specific isotope dilution mass spectrometry analysis (SSIDMS) for determination of the true concentration of methylmerury in biological (hair) and environmental samples (soil and sediment).

The isotopically enriched MMHg has been synthesised from inorganic standard solution prepared from commercially available mercury oxide (201HgO) using methylcobalamin co-enzyme as methylation agent.

The synthesis time required is 1 h at 37°C.

The product is highly pure, yielded more than 95% as201Hg in MMHg.

The proposed method is allows control of unintentional formation of health hazard dimethylmercury.

It is also allows work on a micro-scale to control the use of expensive enriched isotope standard.

The synthesised product was analysed using capillary gas chromatography (CGC) coupled with inductively coupled plasma mass spectrometry (ICP-MS) after derivatisation with sodium tetraethylborate (NaBPr4).

The concentration, purity, isotopic composition and stability of synthesized, enriched MMHg have been investigated in order to establish standard protocols for MMHg isotope dilution analysis