Photochemical vapor generation: a radical approach to analyte introduction for atomic spectrometry

Photochemical vapor generation (PVG) is the newest subset of widely used vapor generation techniques to be coupled to atomic and mass spectrometries to provide enhanced analyte introduction efficiency. Improved detection power, minimization of potential spectral interferences and the promise of green chemistry serve as additional drivers. PVG has been successfully applied to the conventional suite of elements typically amenable to chemical vapor generation, such as As, Sb, Sn, Bi, Se, Te, Hg and Pb, as well as transition metals (Cd, Fe, Co, Ni and Os) and non-metals (I and Br). This tutorial provides an overview of developments and applications since its inception in 2003, including consideration of needed hardware (UV photochemical reactor and phase separator designs), reaction mechanisms and products, interferences, as well as benefits and short-comings. While significant advances have been made over the past decade in expanding the scope of elements amenable to PVG, the way forward demands elucidation of reaction mechanisms to support optimization, enhance prediction power and provide comprehension and control of potential interferences. In this connection, speculations on ultimate limitations, needed developments and future outlook are also presented. More applications to real-world samples are needed to sustain interest in the field and elicit further investment of research.