WEF Discussion Forums
Laboratory Management and Technical Issues
Low Level Mercury - Instrumentation & EPA 1631 Rev. E
I am interested in hearing any comments regarding recent Gold and Soda Lime Trap issues that may be leading to signal suppression of Hg readings? Recently, we have seen signal suppression on samples, blanks, standards, and other qc samples that we've traced (we think) to the Gold Traps and perhaps the Soda Lime traps and specifically the silanized components of those traps.
Has anyone experienced the same thing recently or in the past? If so, what was done to resolve the issue?
This is a new one for me. I'd be very interested in anything that has been published/written on this.
Our concerns over 1631E are not instrumental. We (and others) have found that the room temperature, BrCl digestion can "miss" a lot of mercury in domestic and industrial wastewater, by over an order of magnitude in some cases.
We've raised the issue a number of times with the EPA, but they are totally uninterested, claiming that the caution already in the digestion part of the protocol is enough. We put out a paper in WER and have given a number of talks at national meetings, but have been unable to get the EPA to toughen-up the language in the method.
City of Portland, OR