Determination of Mercury in Drinking Water by Inductively Coupled Plasma Atomic Emission Spectrometry with Electrothermal Vaporization

The determination of mercury at the ng/mL level is needed in clinical, environmental, and occupational hygiene studies. The cold vapor atomic absorption technique for the determination of mercury in water is applied widely. An alternative approach is electrothermal atomization atomic absorption spectrophotometry (ETAAAS). The major limitation of this latter technique results from the extreme volatility of mercury, and a significant loss is observed when one is drying a mercury salt solution in ETA-AAS. Ediger reduced mercury volatility by thermal stabilization with ammonium sulfide. Halasz et al. compared sodium sulfide and dithizone as mercury stabilizing agents to find that in the presence of dithizone higher charring temperatures were usable. Recently Takla and Valijanian extracted mercury with dithizone, and the mercury-containing extract samples were dried and ashed prior to atomization at up to 250°C without loss. Lapanja et al. searched for stabilizing reagents for mercury and investigated the atomization of organic mercury chelates. The thermal decomposition product of these stabilizing reagents was HgS.