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Mercury Analysis in Environmental Samples by Cold Vapor Techniques

Environment: Water and Waste

  1. Kim A. Anderson

Published Online: 15 SEP 2006

DOI: 10.1002/9780470027318.a0841

Encyclopedia of Analytical Chemistry

Encyclopedia of Analytical Chemistry

How to Cite

Anderson, K. A. 2006. Mercury Analysis in Environmental Samples by Cold Vapor Techniques. Encyclopedia of Analytical Chemistry. .

Author Information

  1. Oregon State University, Corvallis, USA

Publication History

  1. Published Online: 15 SEP 2006


The accurate, precise, and automated determination of mercury in biological and environmental samples is complex, not only because of the various oxidation states of mercury (i.e. 0, I and II), but also because of biotic and abiotic methylation and the volatility of several forms of mercury(I and II). Mercury is unique among the metals because of its large vapor pressure at ambient conditions. Mercuric ions in solution can be reduced by tin(II), or sodium borohydride to produce volatile elemental mercury, referred to as the cold vapor process. The mercury is swept out of solution with a carrier gas (in the gas of sodium borohydride, the byproduct is hydrogen) into the cell (or torch) where the atomic absorption (or fluorescence, or emission) is measured. The cold vapor technique removes the mercury from the sample matrix, concentrates the mercury in the analytical sample into a small plug of carrier gas, and provides for a relatively long residence time. Detection limits vary depending on the instrument but are in the submicrogram to nanogram per liter range for atomic absorption spectrometry (AAS), atomic fluorescence spectrometry (AFS), and inductively coupled plasma atomic emission spectrometry (ICPAES).