Plasma induced chemical vapor generation for atomic spectrometry: A review

Plasma induced chemical vapor generation (plasma induced-CVG) is a promising new vapor generation technique coupled with atomic and mass spectrometry, notable for its enhanced sensitivity and selectivity. The analyte could be converted into a volatile species simply by the free radicals and electrons generated by the plasma chemical processes. Plasma induced-CVG offers several advantages including avoiding the use of unstable chemical reduction/oxidation reagents, high vapor generation efficiency, fast reaction speed, simple device structure, and easy construction. Since it was first used as a sampling interface for atomic spectroscopy in 2008, plasma induced-CVG has been successfully applied to the vapor generation of As, Sb, Bi, Se, Te, Hg, Tl, In, Pb, Cd, Zn, Ag, Os, and I. This paper provides an overview of the developments and applications of plasma induced-CVG, including liquid electrode discharge plasma induced-CVG and dielectric barrier discharge plasma induced-CVG. Specifically, we summarized the influence of different discharge devices, operating parameters, and the interference of coexisting ions on the vapor generation method. The possible mechanism and future development trend of plasma induced-CVG are also discussed. Although significant progress has been made in expanding the scope of applicable elements of plasma induced-CVG in the past decade, further development requires better understanding of the reaction mechanism in order to better optimize experimental parameters for improving the analytical performance (sensitivity, and robustness, etc.) and application to real samples.