In recent years the application of the inductively coupled plasma (ICP) has been extended to plasma source mass spectrometry (ICP-MS), as well as to gas, high-performance liquid, and supercritical fluid chromatography (GC, HPLC, and SFC). Argon typically is the discharge gas, although some developments with helium have been undertaken. Common molecular gases including air and nitrogen also can be used as the discharge gas. For example, a nitrogen ICP would be useful for ICP-MS.
Pengyuan Yang, Ramon M. Barnes, Jodi Vechiarelli, and Peter C. Uden, "Low-Power Nitrogen and Carbon Dioxide Inductively Coupled Plasmas for Spectrochemical Analysis," Appl. Spectrosc. 44, 531-535 (1990)