FIELD ANALYSIS OF MERCURY IN WATER, SEDIMENT AND SOIL USING STATIC HEADSPACE ANALYSIS

We developed a field screening method for the rapid analysis of mercur y (Hg) in water, soil and sediment which can be applied cost-effective ly at Hg-contaminated sites. The samples are chemically pretreated in ordinary containers, followed by analysis of the sample headspace Hg v apor using a portable commercially-available analyzer. Mercury in wate r samples is reduced directly by the addition of stannous chloride, wh ile solids are first digested with aqua regia or piranha solution to l iberate the Hg from the solids. Aided by vigorous agitation after addi tion of the reductant, the elemental Hg partitions between the solutio n and headspace according to Henry's Law. The method requires about 2 and 15 minutes to complete for water and solids, respectively. The met hod provides very useful detection limits for water (0.1 mu g/L) and s olids (less than or equal to 2 mu g/g). Intercomparisons with laborato ry-analyzed environmental samples have shown reasonable agreement.