INDUCTIVELY COUPLED PLASMA MASS-SPECTROMETRY WITH DIRECT INJECTION NEBULIZATION FOR MERCURY ANALYSIS OF DRINKING-WATER

An improved technique has been developed to determine concentrations of mercury in drinking water. Inductively coupled plasma mass spectrometry (ICPMS) with direct injection nebulization (DIN) was used for the analysis. A characterization was conducted and optimum operating parameters found. The mercury detection limit with the DIN was comparable to a conventional pneumatic nebulizer f PN) while the inherent problems of memory effects were drastically reduced. The extent of spectral interference due to refractory oxide formations was compared using the DIN and the PN. Actual drinking water samples were spiked with varying concentrations of mercury and analyzed along with certified reference materials using DIN-ICPMS. Duplicate analysis was conducted between the DIN-ICPMS and the conventional technique of cold vapor atomic absorption spectrophotometry (CVAA) and a comparison made.