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- Posts: 40
- Joined: Tue Sep 13, 2022 1:09 pm
- Location: USA
Some manufacturers are now requiring (or strongly recommending) "zero-air" for ESI source gas, while others are requiring nitrogen for the source gas. This is source gas only, not sweep or collision. The theory I was told was there would be less corona discharge in the source and better sensitivity.
While zero-air should be cheaper to generate than N2 (in theory), nitrogen is still needed for other uses on these mass spectrometers; therefore, it actually increases cost and complexity of supplying 2 (or more) separate gases.
Our laboratory has been using pure N2 as a source gas for years. We recently put a single method head-to-head on the same instrument with N2 versus zero-air as the source gas using identical settings. We saw no difference in any results, but that was for a single method.
Has anyone actually observed where there is a significant benefit to using zero-air over N2 as the source gas? What conditions/compounds/method was this for?
(I would presume that N2 would offer longer gas heater life and less chemical oxidation for some compounds in the source and a theoretical higher fire risk -- but these are both only theories too.)