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Probleme of GCMS 4000 Varian

Posted: Wed Dec 23, 2009 10:19 am
by mabrouk mahmoud
Hi everyone
I have a problem with GC MS 4000 Varian, The Source temperature can't reached the actual temperature (200°C) it's stiil in 100 °C.
The conditions of the instrument are:
external source, damping gaz: 1 ml/mn, T gater: 425°C, T source 200, T trappe: 200, T tranfert line: 250, T manifold: 40, T colonne: 200, T inj: 250,
split 1/10, pump foreline: 32 mtorr, pump turbo: 15 µtorr, current: 237 mA,
pump speed 100%.
When I make the auto tune, the rapport is passed, but is indicate. There is a problem of the temperature of source.
Can I work and the temperature of the source is 100°C?

Posted: Wed Dec 23, 2009 12:55 pm
by willnatalie
You could try, but you might eventually have some problems with water, or even some of you analytes, if they are larger molecules (b.p > 100C). If the source is not hot enough, many large molecules will not be vaporized and sent into the MS. Some could stick to your source and leach into the MS yielding an uneven base line. If you have the money and the time it might be worth looking into.

Good luck.