Novel Palladium Coated Tungsten Coil Atom Trap for Ultra-Trace Determination of Selenium by Hydride Generation Atomic Absorption Spectrometry (HGAAS)

Abstract

A new ultra-sensitive method was developed for selenium (Se) determination by combining a Pd-coated W-coil atom trap with hydride generation atomic absorption spectrometry (HGAAS). Firstly, gaseous hydrogen selenide, generated using a hydride generation system, was transported to an externally heated atom trap for in-situ preconcentration, where it was accumulated at 210 °C. Subsequently, the atom trap temperature was adjusted to 930 °C for revolatilization, resulting in the acquisition of a transient analyte signal within a very short time. The detection limit of 2.6 ng L−1 Se for a 90 s collection and a relative standard deviation of 2.4% for 0.01 µg L−1 Se (n = 14) were obtained. The devised trapping technique exhibited a remarkable 38-fold increase in sensitivity when compared to the conventional HGAAS method, as indicated by the characteristic concentration (C 0). The surface morphology was examined using scanning electron microscopy and energy dispersive spectroscopy. The proposed technique was validated by the analysis of certified reference materials (CRMs) and employed in the assessment of tap water samples. Statistical analysis using a t-test was conducted on CRMs and water samples, and the results showed no significant error.