Nippon MA-2 Mercury analyzer

Analysis of Total Mercury in Solid Samples by Atomic Adsorption following Direct Combustion with the Nippon MA-2 Mercury Analyzer.

The following standard operating procedure (SOP) is used by the U.S. Geological Survey’s Mercury Research Laboratory (MRL) to determine total mercury (HgT) concentrations in solid samples. This SOP describes the preparation of the sample and subsequent analysis. The Nippon MA-2 is a direct combustion instrument designed to analyze total mercury in solid samples. The solid sample is combusted at high temperature (850°C) in the presence of interference-reducing reagents, releasing mercury from the matrix as reduced gaseous mercury. In the resulting gas, matrix interference is further eliminated by catalytic treatment, adjusted to appropriate pH in a phosphate buffer, and then passed through a gold amalgam trap to quantitatively capture gaseous mercury. Lastly, the gold trap is heated, releasing the bound mercury into the sample stream, and detected by cold vapor atomic adsorption. Quality assurance and control protocols are employed throughout sample preparation and analysis, including: laboratory practices to prevent sample contamination, analytical blanks, method and analytical replication, and analysis of certified reference materials (CRM).

Mercury Research Laboratory, 2016