New analyzer detects PPQ levels of mercury

Environmental NEWS - Fall 2006

Just how small is a part per quadrillion (ppq)? Although this ultra low concentration is equal to just one penny in $1,000,000,000,000, chemists in the Metals Analysis Group are preparing to use a mercury analyzer capable of measuring in the ppq range. The new instrument utilizes atomic fluorescence detectors and gold amalgamation traps to concentrate and measure amounts as low as 50 ppq of mercury in water samples. The system also employs dual detectors to prescreen samples for unexpectedly high concentrations that could foul the sensitive instrument.

Mercury is a highly toxic element known to bioaccumulate in the food chain. For this reason, both national and state environmental agencies severely limit the amount of mercury allowed in discharges, sometimes requiring permittees to report levels that are not achievable using standard cold vapor atomic absorption techniques. After installation is complete, clients will be able to meet these strict permit levels by requesting the new low level mercury analysis, which is based on EPA methods 245.7 and 1631.

Parker Lindstrom, senior chemist, prepares the
HYDRA AF Gold Plus Mercury Analyzer
for water sample analysis.

The new technology comes with the challenge of controlling the laboratory contamination issues that can occur with trace measurements. “We are in the process of constructing a custom Plexiglas enclosure to prevent contamination of the instrument. It uses positive pressure and HEPA filtered air to maintain a clean environment,” says Bob Strocko, manager of the Metals Analysis Group. He anticipates that the instrument will be ready for use by the end of the year. The laboratory is currently evaluating accreditation options for the new methods.

For more information about low level mercury analysis, please call client services at (717) 656-2300.