A novel atmospheric pressure glow discharge system for sensitive determination of As, Sb, and Se by optical emission spectrometry following their hydride generation.

Hydride generation (HG) was combined with an atmospheric pressure glow discharge (APGD), sustained in a completely novel system, to sensitively determine As, Sb, and Se by optical emission spectrometry (OES). The carrier gas with the analyte hydrides produced by chemical HG together with co-generated H 2 was introduced into the APGD system, where atomization and excitation processes took place. It was revealed that the essential factors responsible for the high stability of the plasma were its operating with He discharge gas (instead of Ar), operating the gas nozzle (used to introduce carrier He) as a cathode, and forcing the cathode spot to cover most of the surface of the gas nozzle. Under optimized operating conditions, the measurement repeatability was 2–3%, proving the high stability of the HG-APGD system. The detection limits (DLs) of As, Sb, and Se were 0.6, 0.14, and 1.2 μg L−1, respectively, and compared to those previously reported for HG-APGD with liquid electrodes, the DLs were improved over 3 times. In addition to improved DLs, the novel system offered a simplified and more compact design. The accuracy of HG-APGD OES was verified using a recovery test and proved by high agreement between spiked and measured concentrations of As, Sb, and Se in mineral and tap water samples, reaching recoveries within the range of 96–103%. [Display omitted] • A very simple microplasma excitation source was coupled with a hydride generation. • The operating parameters of the novel microplasma source were studied in detail. • The detection limits of As, Sb, and Se were 0.6, 0.14, and 1.2 μg L−1, respectively. [ABSTRACT FROM AUTHOR]