Chromatography Forum

Hello Friends,

I work at a small liberal arts college where I do research using a Thermo 1300 GC paired to a Thermo ISQ MS. When I started to use the instrument for research and not just teaching it took a long time to clean it, and replace parts to get it working at the research grade.

Now my administrators are saying they want to turn off all power to the campus due to COVID-19 and having everyone work remotely for the foreseeable future. I urged the administrators to keep the power to my lab on so that I can keep the GC in rest mode, under vacuum and keep the sourced heated and clean, and carrier gas flowing. In the event that I have to turn it off for say 2 months or so what would be the best protocol to produce as little downtime as possible when I start it back up?

Would it be worth it to remove the column and cap the MS off with a blank ferrule? Would it be best to keep carrier gas flowing (UP H2)? Would it be worth it to remove the column and cap both ends of that as well?

Thank you for your help, this is an upsetting situation.

Are you able to set a low resting flow rate and then check the gas cylinders every week or two? As an add-on to that, will you be able to get gas delivery if needed?

I was faced with a similar decision this past week, as the order came last Saturday to prepare for remote work by yesterday. I spent Monday shutting down and venting my three GC-MSs. One actually came home with me, as I'm planning a major electronic refit . In any case, I just let everything cool down and left it as-is with the supply lines fed N2. I'm going to be going in every other week or so.

BTW, we were initially told a 3 week shutdown(April 5th), but that was extended yesterday to April 28th and it may well be longer. Some here advised me to leave them under vacuum with the heated zones off and no carrier gas flowing, but I wasn't comfortable doing that with no guaranteed return to service.

If you could switch to nitrogen as a standby flow then you would be ok, I don't think it would be a good idea to keep H2 flowing if everything is shut down unless you have a way to vent it outside the building. If the normal HVAC will still be running and you could keep any vent hoods going then it might be fine, but the last thing you would want is for the H2 to build up for a month then turn on the lights when you return and get a spark.

Under vacuum unheated with a flow of nitrogen would be best, capped and no flow would be second best. If the rough pump has to be switched off then you either need a valve between the pump and the MS or have the MS vented, you don't want to take the chance that the vacuum will suck oil or oil vapors back into the analyzer. If shutting down the vacuum I would flush well with nitrogen, after the pump is turned off until you are near atmospheric pressure, then cap the inlet, that should protect it from moisture and prevent any back flow of oil.

Why not leave it heated and under vacuum?
It's a virus that's comming not a tornado so I don't see why you would shut down your system for it.

Switching to nitrogen as carrier is ok and lot cheaper than He of H2 so that makes sence.

If you switch off al the power in the building what will happen to your standards (in fridge, freezer) ?

Hi there,

A similar question was addressed in the forum topic below if that's of any assistance:

'Shutting Down GC-MS System'
https://www.chromforum.org/viewtopic.php?t=89984

How has your experience been with the ISQ incidentally? We're considering purchase of the LC variant in the near future.

Cheers, Matt