Chromatography Forum

Would it be OK to use compressed air to dry samples prior to GC/MS analysis? (solvents, derivatizing agents, etc.)? Or using nitrogen gas is better? I tried both and didn't see any difference but yet most labs use nitrogen, in many cases UHP Nitrogen...

Many lab 'air' lines are not immaculate in their composition.

They may have pump oil, or other contaminants (even water !) .

High purity nitrogen also prevents (or delays) any oxidation process that COULD occur in the drying process.

If it is important enough to spend your time in doing it, it is important enough to do it right the first time.

IMHO

Some folks like to gamble. Others like to keep their gold in the bank.
Whatever works for you.

Rod

I tried both and didn't see any difference ..

You apparently have proved that for your samples that it doesn't make any difference. So trust your data on those types of samples.

I would plug cotton into the delivery tube of my air supply in case there's trace oil. Maybe your compressor is oil-free. But when our guys got cheap and replaced one with an oil-lubed compressor, for which they claimed that the would religiously change/clean the trap system ... does anyone want to guess what started appearing in our air lines???

No chicken dinner to the winner.