I am new to the forum and full disclosure not an expert at GC-MS systems. However, I am a chemistry professor at a small liberal-arts school which kind of makes me a jack of all trades and puts me in charge of our instrumentation (I have the most experience of the faculty here). Anyways, we recently purchased and installed a refurbished Agilent 6890-5973 GC-MS system using He gas as our carrier. Currently, this instrument will only be used for teaching purposes, meaning it will only be used a couple of times of year in our Instrumental Analysis course and not for very sensitive quantitative work. With money always tight, I was wondering if it would be okay to shut the system down while it is not being used to conserve He gas. I know it is preferred to keep the system on and pumped down and gas flowing, but we are working to save as much as money as possible, and since the instrument will sit idle for several months, it seems somewhat wasteful to keep it running.
So first, is it possible to leave the MS system under vacuum without the carrier gas on? I would guess this means turning the temperature down or off on the filament, which is fine. I also know we would set the GC oven temperature to ambient while it is shutdown. So any advice I could receive from the experts here is GREATLY appreciated! We want to teach our students the importance of GC-MS, but also do so in an economic fashion!
Thanks again for any help!