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- Posts: 52
- Joined: Sat Jun 27, 2015 12:03 am
I'm having an issue with one of our 524.2 instruments. Earlier this week the recoveries suddenly dropped to ~15% of the calibration. I've tried everything i can think of to locate the issue and can't.
I'm running an Archon connected to an OI 4560 to 6890/5973. 11 minute purge at 40 mL/min 1 minute dry purge, desorb pre-heat to 135 and 4 minute desorb at 190 (we can't change the desorb time) and a 10 minute bake at 210. so far i've run an electronic leak detector over every line and joint and found nothing. I measured the flow from the Archon (we use soil mode for everything) and it's right about 40 mL/min. i then took the trap off and put the flow meter at the water management were the trap connects and it measures ~ 40 mL/min. From the transfer line to the GC only measures only 5-8 mL/min. So far i've tried changing the P&T-GC transfer line, 6-port valve, and the lower valve on the manifold. None of that changed anything, i'm concerned it might be the EPC on the 6890 but don't have one to swap out and check. Does anyone have any ideas?
quick edit: i did do a direct inject and everything was fine.