I am running masshunter workstation Quant v10.2 build 10.2.733.8 (enviromode) with masshunter workstation data acquisition v10.2.489. I am building EPA method 624 (purgeables) from scratch and having some trouble with some primary quant ions for certain compounds not showing up in the MS spectrum at low calibration levels (0.5 ppb) due to their naturally low abundance in relation to the other ions within the particular spectrum window. Raising the gain factor helps with this, but also causes early eluting compound accuracies, that were otherwise OK, to sky rocket over 200% in some cases, with or without weighting. My threshold in acquisition is currently 150. Instead of raising the gain factor, could lowering the threshold help to capture these low abundant quant ions without raising the abundances of some of the early eluting ions? Or is there something else that could be done instead?
I run this with an ATOMX purge and trap system. I have been trying different split ratios between 50:1 and 125:1 but this doesn't seem to make much of a difference with the quantitation. Other than that I do not change purge and trap parameters.