Ultratrace Determination of Tin, Germanium, and Selenium by Hydride Generation Coupled with a Novel Solution-Cathode Glow Discharge-Atomic Emission Spectrometry Method.

We herein describe a novel method of hydride generation (HG) coupled to a newly designed atmospheric pressure solution-cathode glow discharge (SCGD) spectrometric technique for the ultratrace determination of tin, germanium, and selenium. In this novel SCGD process, gas introduction was permitted using a hollow titanium tube as both the anode and sampling port. In these experiments, the analytes were converted into volatile hydrides upon passing through the hydride generator, and were introduced into the near-anode region of the SCGD system, where they were detected directly by atomic emission spectrometry (AES). A significant improvement in both selectivity and sensitivity was achieved, which was reflected in an improvement in the detection limits (DLs) by 3 orders of magnitude, in addition to successful valence analysis of Se without the requirement for chromatographic separation. In the absence of a strict sample pretreatment process and with a reduction in electrolyte consumption, the detection limits of Sn, Ge, and Se were determined to be 0.8, 0.5, and 0.2 μg·L. Moreover, our HG-SCGD-AES system demonstrated excellent repeatability (<3% peak height relative standard deviation) and more than 2 orders of linear dynamic range. The optimal operating conditions are outlined herein, and the analytical performance of the system is evaluated as described. Furthermore, our method was applied for the analysis of Sn, Ge, and Se in both environmental and biological samples, and the obtained results were in good agreement with reference values.