I use an Autotrace for extraction of drinking water for EPA 525. Early in the year I started loosing about 50% of my spiked compounds. I had the system rebuilt and it is working better, but not as good as when it was new. I still loose endrin, hexachlorocyclopentadiene, and metribuzin. There were a few parts that are not part of the rebuild. The ones that most concern me are the sample pumps. I'm wondering if something could be growing in the pumps.
Anyone have any suggestions?

Thanks