I am trying to bring up a Varian 3400 GC running an ECD for detection of trihalomethanes (such as chloroform) and haloacetic acids. We are running into a few problems as we are trying to set up our instrument to run the EPA 502.2 method (enviromental protection agency method for measuring disinfection by-products by use of chlorination of water). I wanted to start a thread here where i can troubleshoot with you all because i'm tired of spending hours flipping through useless manuals and online pdf files.

So, our problem is we are trying to figure out if our detector (an electrolytic conductivity detector, ELCD) is dead or if our purge and trap system is bad...so we have disconnected the TRACOR GC and we are going to bring up the Varian 3400 GC-ECD, and hook that up to the purge and trap to rule it out as the problem.

So the first thread question here is what should my flow rates be if i wanted to use just nitrogen for both my make-up and carrier gases? The column is a Restek, phase MXT-1 (used for EPA 502.2). The flow was set earlier today to 10mL/min through the column and 20mL/min make-up gas for a total flow of about 30cc. We are allowing it to flow for about an hour and a half (as i am writing this) then I plan to disconnect the column from the detector and bake it out. Does this sound like an appropriate proceedure for bringing up this instrument?