Experimental study on the unintentional abiotic methylation of inorganic mercury during analysis: Part 1: Localisation of the compounds effecting the abiotic mercury methylation

An attempt was made to investigate the causes and factors involved in methyl mercury formation during analysis. A hyphenate HPLC-UV-PCO-CVAFS and a HPLC-ICP-MS technique was used in the completion of the isotope experiments. All mercury methylation experiments were carried out under conditions similar to those of the water vapour distillation method. The sample matrices, which showed the highest artefact formation potential, were further investigated using different extraction methods. The compounds responsible for higher artefact formation were especially well extractable using polar organic solvents such as acetone and acetonitrile and less soluble in nonpolar solvents such as toluene and hexane. The extracts were further separable with thin layer chromatography and with the aid of a packed liquid chromatography column. Methylation experiments using different model compounds of metabolisms from humic substances were carried out to give an idea of the compounds responsible for the methyl group transfer to inorganic mercury. (C) 1999 Elsevier Science Ltd. All rights reserved.