Simultaneous separation of organomercury species by nonaqueous capillary electrophoresis using methanol containing acetic acid and imidazole

Abstract

A simple and rapid nonaqueous capillary electrophoresis method for simultaneous separation of four kinds of mercury species, namely inorganic mercury, methylmercury, ethylmercury, and phenylmercury, is reported. The effective mobilities of organomercury in aqueous and nonaqueous electrolytes were compared. Imidazole was confirmed not only as a co-ion for the separation but also as an online complexing reagent for mercury species. The optimum conditions for separation were achieved by using methanol solvent containing 0.15 M acetic acid and 15 mM imidazole as electrolyte. The sensitive detection of mercury species was accomplished at 191 nm.

Development and application of a poly(2,2′-dithiodianiline) (PDTDA)-coated screen-printed carbon electrode in inorganic mercury determination

“…Methylmercury usually enters and can be accumulated in the human body after consuming fish that was contaminated. Hair is one of the main accumulation and identification sites of mercury [4][5][6][7].…”

Mercury speciation by CE: A review

“…While inorganic mercury species (Hg 2 21 , Hg 21 ) have appreciable water solubility, the aqueous solubility of organomercury compounds in water is limited and must be improved by adding organic solvents, e.g., methanol. Direct CE separation of mercury compounds without derivatization is thus non-trivial and of all publications concerned with CE speciation of mercury, only three [17][18][19] cover the direct separation of mercury species. Although derivatization is not necessarily a desirable step, it provides for two significant improvements in CE.…”

“…Peng et al [19] have examined nonaqueous separation of four mercury species in a BGE composed of 0.15 M acetic acid and 15 mM imidazole in methanol. Direct UV-Vis absorptiometry at 191 nm was used.…”

Recent trends in CE of inorganic ions: From individual to multiple elemental species analysis

“…Significant changes in selectivity for common inorganic anions upon increasing the percentage of methanol in the BGE were observed by Diress and Lucy [116,117]. Metal ions [118][119][120][121] or their inorganic and organic forms [122] can be well separated by NACE, methanol being the most appropriate solvent; however, peak shapes and efficiencies remained marginal. The alterations in mobility compared to that observed in water-based electrolytes are commonly ascribed to changes in solvation of ions.…”