Posted: Wed Feb 03, 2010 7:11 pm
by mfiligenzi
A friend of mine blew the oven door off of his GC/MS using hydrogen. I don't know what caused the leak, but as in the other cases this happened about twenty years ago prior to the use of electronic pressure control systems.
Posted: Fri Feb 05, 2010 11:50 am
by Ron
Even if you use hydrogen with 7 9s purity you will have more baseline noise. There is higher pressure in the vacuum chamber and more neutral noise with hydrogen, and these factors lead to a noisier baseline. I looked at extracted ion chromatograms of ions commonly found in the baseline noise using helium carrier and found lower intensity of these ions using hydrogen carrier. The overall random noise was higher, so as a result the baseline was higher and noisier.