Investigation of time-resolved OES for trace element analysis: ICCD study on volume DBD / APGD plasma sources
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| Year of publication | 2025 |
| Type | Appeared in Conference without Proceedings |
| MU Faculty or unit | |
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| Description | Various pulsed plasma sources have been investigated for their use in trace element analysis, including configurations based on dielectric barrier discharges (DBD) and so-called atmospheric pressure glow discharges (APGD) combined either with liquid sampling (liquid electrode), or with gaseous analyte introduction via hydride generation (HG). (Note: The APGD nomenclature has been given also to homogenous regime of volume DBD, which is not the case here.) In this contribution, the atomizers based on volume DBD and APGD were operated in Ar at atmospheric pressure with analyte introduction in the gas phase by HG. Model analytes included both atoms (Hg, Cd) and molecules - hydrides (AsH3, SeH2, CH3HgH). Molecules were atomized and free atoms subsequently electronically excited in the discharge to be detected by optical emission spectroscopy (OES). The phase-locked diagnostics using ns-gated intensified CCD camera (Andor iStar DH340T-18F-03) mounted on monochromator (Andor Shamrock 750) revealed the delayed temporal evolution of spectral constituents. The OES of low-intensity signals represents a challenging task considering the low signal-to-noise ratio. Photomultiplier-based single-photon-counting techniques (SPC) have been developed to reach the ultimate sensitivity. The possibilities of ICCD-based (SPC) spectroscopy are evaluated here. |
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