Chromatography Forum

I'm looking for an alternative to using mercury clean up on samples being ran on a gc with ECD, method 8081, and 8082.

Ive tried copper and TBA but neither are as effective as the mercury, and they tend to lower recoveries.

The issue I have with mercury is that in the same building they do low level mercury analysis and even a tiny bit of mercury cleanup in a hood on the opposite side of the building causes issues with the instrument. Any ideas on another cleanup method or a good way to prevent contamination of the mercury instrument.

I looked at the alternatives when we stopped using mercury in the late 90's. The TBA worked the best although the copper was about the same if the copper surface was very clean. A little nitric acid helps a lot. GPC cleanup was not quite as effective and much more work. I could check the removal efficiency using a GC with an atomic emission detector on a sulfur channel. With a little practice I was getting a consistent ~95 to 98% removal with one treatment, about the same as with mercury and I wasn't creating a health and safety hazard in the lab.

The TBA seemed to have the least problem with analyte loss, your results may differ, and the wash step helped with some interferences.
I moved on to volatiles and LC/MS, the current users rely on copper for sulfur removal.
One caveat, we don't analyze for the standard chlorinated pesticide list anymore. Our pesticides are now done by GC/MS-MS.