make up gas

[rblucke]

Make-up gas may not be needed for FID. We have not use it for 7 GC's for several years (thousands injections of complex mixtures). Response is a little lower but the precission seems to be better or equivellent without make-up.

We are using a 10m x 0.1mm ID column with H2 as carrier gas.

[lgchrom]

In which cases is the make up gas not needed. Can you please specify?

[LindseyPyron]

We supply H2, N2 and Zero Air Generators - This has been a big issue due to the cost of helium going through the roof. From a safety standpoint, most companies believe H2 generators are safer than H2 tanks. 1.) You are not moving tanks around, 2.) if there is a leak and pressure drops, the H2 generator will shut off, and a tank will just keep sending H2.

H2 is not explosive until it gets to more than 4% in an oxygen rich environment. Because it dissipates so quickly, running H2 as a carrier gas, even with high split flows, is not a problem.

FYI~
If you are looking into generators, make sure you understand the long term cost. The maintenance on some designs is quite high and can be more than the cost of the generator over time.

[chromatographer1]

As long as your space above the lab is drafty and not sealed well you should have no problems with hydrogen. But if the crawl space above the lab is tightly sealed, if the attic so to speak, is not well ventilated, then concentrations can get too high over time. GRANTED hydrogen will seep out at every opportunity it has and will escape your building at any chance, it is a cheap and p rudent precaution to have splitter vent lines pass directly outside the building, through vents or out a side wall or window.

If that tech on the Hindenburg had used chew instead of that cigar, history would have been changed !

best wishes,

Rod