additional gases

in flame atomic spectroscopy
https://doi.org/10.1351/goldbook.08448
Gases added to a combustion mixture.
Note:
An inert diluent is non-reactive, an auxiliary gas is reactive.
Source:
PAC, 2021, 93, 647. (Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)) on page 712 [Terms] [Paper]