-
- Posts: 3
- Joined: Wed Mar 25, 2020 6:28 am
I've been using LC-MS for some time now, but unfortunately, I have no mentor to ask all the questions in mind so I will really appreciate your expertise.
My main concern is the hardware and keeping it clean and undamaged. There have been a few gas shortages and I would love to know the best practices for a situation of this kind.
The instrument in question is QTRAP. I've been told that if there's no gas flow I should monitor the system vacuum and if it falls below a certain level there's a risk of instrument contamination.
Why would the system vacuum keep increasing over time if there is no gas flow? The normal operating pressure of the instrument is 2x10^-5 Torr (system running) / 0.6x10^-5 Torr (system idle). I assume the decrease in vacuum when running is caused by the increased gas flow (compared to idle)?
Now, the normal (idle) pressure being 0,6x10^-5 Torr, what would be a harmfully low pressure for this system that could cause contamination?
How long, approximately, is it safe to have the instrument with full vacuum in case of gas shortage? The LC would be detached at this point, of course.
Thank you for reading and I hope you’ll find the time to share your knowledge.
Stay healthy, everyone!