Comparison of Digestion Methods for the Determination of Total Mercury in Environmental Samples by Flow Injection CV-AAS

摘要

Three closed digestion methods were evaluated for the fast, accurate and precise determination of total mercury in environmental samples by flow injection cold vapor atomic absorption specirometry. The method based on the use of HNO_3-H_2O_2 mixture with microwave oven pre-treatmenl was found to be the most suitable for reliable determination of mercury. The methods based on the use of HNO_3 for digestion gave incomplete recovery of methyl mercury and the determinations were strongly interfered withby the volatile nitrogen oxides. This interference was not observed with the HNO_3-H_2O_2 digestion mixture. The application of the best method to mercury deposition study provided accurate and reproducible analytical data.