Development of an easy portable procedure for on-site determination of mercury and methylmercury

A portable measurement and speciation procedure for inorganic mercury (HgIN) and methylmercury (CH3Hg) was developed. A portable sample pretreatment was optimized to determine total mercury content. A new homemade sorbent (CYXAD, CHYPOS 101 modified Amberlite XAD), was prepared to separate HgIN and CH3Hg. Mercury species were determined using square wave anodic stripping voltammetry (SW-ASV) with a solid gold electrode (SGE) and using a portable potentiostat. A certified reference material, five freeze-dried samples and three fresh samples were analysed with conventional voltammetric analyzer, after dissolution of the samples in microwave oven, and with a portable potentiostat after the mild eating procedure. The results obtained by SWASV were compared with those obtained using Direct Mercury Analyser (DMA). The quantification with the portable method is comparable to that obtained with the DMA. Retention tests showed the selectivity of CYXAD for HgIN, its stability and the possibility to re-use the same aliquot of resin.

Automated summary

A portable measurement and speciation procedure for inorganic mercury (HgIN) and methylmercury (CH3Hg) was developed, showing comparable quantification results to Direct Mercury Analyser (DMA). The new homemade sorbent demonstrated selectivity for HgIN and stability during retention tests. Overall, the portable method offers a convenient and reliable way to determine mercury species in samples.