Symptoms of Air damage to GC-MS

[metenglab]

I recently switched out helium tanks, but there was a leak in the fittings and my tank ran empty. It was at least 2 hours before I noticed and was able to cool and vent the system. Does anyone know what kind of damage this might have caused and how I can go about testing the system when I restart? I have a bruker 450 gc connected to a varian 300-ms. At the time the inlet temp was 250 C, oven temp 150 C, and source temp 280 C.

[James_Ball]

I recently switched out helium tanks, but there was a leak in the fittings and my tank ran empty. It was at least 2 hours before I noticed and was able to cool and vent the system. Does anyone know what kind of damage this might have caused and how I can go about testing the system when I restart? I have a bruker 450 gc connected to a varian 300-ms. At the time the inlet temp was 250 C, oven temp 150 C, and source temp 280 C.

If a lot of air passed through to the source, the metal parts will have a slightly golden or bluish color to them, unless they are silcosteel then you won't be able to tell.

150c on the column could do some damage, and that would show up as increased bleed from the air on the phase, but if it is not too bad then baking it out will bring it back down. The inlet should be ok, if you see increased breakdown you may need to swap out the inlet port liner.

As long as the filaments were not active they should not be hurt as with the electron multiplier. Electron multipliers would be damaged more if it went to atmospheric pressure than just a little air passing through the system.

[whdees]

you will likely need to trim several inches off the head of the column...

[HbJ]

I've experienced a similar situation and the damage caused was:
- Increased septum bleed, so change it.

- The silanisation of the liner was damaged which affected the peak shapes of active sample compounds, so just change it also.

- Terminal column damage (mine was a RTX-200ms). If you heat out the column, don't connect it to the MS (cap the MS inlet and leave it off e.g.). That way you don't contaminate your MS further. But from my experience, use a new column.

- The broken down phase did contaminate my MS quite a bit and I had to clean it according to the manual. Bonus tip: Your multiplier might be covered in broken down phase too so check the decontamination procedures in the manual. Basically, you just rinse it with the right solvents. A caveat: If you use other solvents than recommended in the manual you might terminally destroy the multiplier, so be careful.

Good luck!