AUTOMATIC METHOD FOR THE DETERMINATION OF TOTAL MERCURY IN FRESH AND SALINE WATERS AND SEDIMENTS

Acid-dichromate and ultraviolet digestion are used sequentially in an automated system to extract mercury from particulate matter and oxidize organomercurials in briny waters and sediments. Mercury is then determined by reduction with tin(II) and cold-vapor atomic absorption spectrometry. The flow-through system is completely automatic and can accommodate samples with particulate solids up to 1 g l-1. The detection limit is 0.02 μg Hg l-1 in water or 20 μg Hg kg-1 in sediments. Both waters and sediments with high chloride levels can be analysed without interference at a rate of 30 samples per hour. © 1979.