Is this a problem with the GC-MS calibrant valve?

[soccerdad007]

Hi all

We have a HP5973 MSD system.
We have been having "lots of fun" with it recently but the current issue is

I noticed that the air levels were rising compared to the tuning ions of the PFTBA - I couldn't find any leaks in the GC or MS. I then checked the PFTBA vial and found it empty. I refilled the PFTBA vial and purged the valve as per the manual.
I found however that I can't tune the instrument at all - the 69, 219 and 502 ions are not found at all - strangely though when I run a sample I find the ions as normal - the sensitivity is lowered but the spectra of my samples give a good library match as normal.

When I try to manually tune using values recent from recent good tune files I find that I can detect ions such as 18 and 28 when the PFTBA valve is closed but as soon as I open the valve in the manual tune page, all those ions disappear and I don't see any others at all (no 69, 219, 502)
I did wonder whether the PFTBA I added to the calibration vial was still good as we have had for a few years but there was no expiry date on the container (it was still sealed).

Any ideas - is it likely to be the calibrant valve as I think

[Peter Apps]

I have known two 5973s whose tuning compound solenoid valve would occasionally stick closed. If you activated the valve you still heard a click as the solenoid kicked, but the poppet did not lift. The tune just showed noise. If I recall correctly a sharp tap with a screwdriver handle got it working again.

Peter

[soccerdad007]

Thanks for all your help. The problem is fixed. The main problem was that the calibration vial was not fully inserted through the o-ring in the calibration vial holder part - It seemed as though it wouldn't insert any further and then suddenly it would and everything is now okay.


Thanks again
Kevin.

[Peter Apps]

Hi Kevin

Thanks for the feedback. I'm glad it's sorted.

Peter