Chromatography Forum

Hello Everybody!!

I'm in problems : I'm developing a method and validating it and I've found that I 've lost linear range.....Can someone tell me if it may be a fault in the GC column performance?.Peak shapes are OK. I tried changeing the trap and it does not improve..

Thank you

Celia

Check your flow rates. Your split ratio can be important with purge and trap (20 mLs/min split vent) and also check your purge and trap sample flow rate (25-30 mLs/min).

celiagg,

Based on your earlier posts, I would propose you reduce your column flow by about 0.4 mL/min. This should put you around 0.8 mL/min which is going to make your run a little longer but I suspect it will improve your linearity. You will want a split ration of about 25:1 to maintain sufficient flow across the trap under these circumstances.

Best regards.

Split flow is very important in the anlysis of volatiles by P&T. Check your injector and liners.