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Archive for the ‘Metals Testing’ Category

Measurement of Trace Level Mercury by EPA Method 1631

Wednesday, February 4th, 2004

Measurement-of-Trace-Leve--Mercury-by-EPA-Method-1631Mercury is responsible for over three-quarters of all contaminant-related advisories for threats to human health. During the 1990’s, the number of mercury related fish consumption advisories more than doubled, despite significant decreases in the total mercury emissions over the last 20 years. The increase in advisories is probably the result of more testing rather than more contamination.

While the contamination is showing up in lakes and fish, most mercury does not come from effluent, rather is derived from atmospheric deposition. Atmospheric transport and subsequent bioaccumulation of mercury can affect aquatic ecosystems far from mercury sources. According to EPA estimates, emissions from coal-fired utilities account for 13 to 26 percent of the total (natural plus anthropogenic) airborne emissions of mercury in the United States. Thus, the EPA has begun to regulate emissions from power plant boilers and process heaters.


Ultra-trace Metals Determinations using Reductive Precipitation and ICP-MS

Saturday, July 26th, 2003

Ultra-trace-Metals-Determinations-using-Reductive-Precipitation-and-ICP-MSColumbia Analytical Services’ Kelso laboratory has continued the development of analytical techniques for pre-concentration and chemical separation of trace metals in saline aqueous samples using reductive precipitation followed by inductively coupled plasma-mass spectroscopy (ICP-MS). This technique replaces conventional techniques for the analysis of trace metals in complex aqueous matrices such as sea water where matrix problems prevent the ability to achieve desired low levels of detection. Detection limits for various metals of interest using these techniques are displayed in the table to the right. Details of this procedure were presented at the recent National Environmental Monitoring Conference (NEMC) held July 21-24 in Arlington, Virginia. The full abstract follows.