A miniaturized UV-LED photochemical vapor generator for atomic fluorescence spectrometric determination of trace selenium

Abstract

A miniaturized UV-LED photochemical reactor is proposed for selenium photochemical vapor generation (Photo-CVG). The miniaturized Photo-CVG reactor with a coin size mainly consists of an ultraviolet light-emitting-diode (UV-LED) and a quartz coil with nano-TiO₂ coating on its inner wall. It was coupled with an atomic fluorescence spectrometer (AFS) as a sample introduction device for trace selenium determination. The nano-TiO₂ coating process, UV-LED wavelength and correlative experimental parameters as well as potential interference were investigated in detail. Under optimized experimental conditions, limits of detection of 0.21 and 0.28 μg L⁻¹ for Se(VI) and Se(IV) were obtained, respectively, with a relative standard deviation (n = 3) of 2.5% and 1.0% at 20 μg L⁻¹. The potential application of this UV-LED Photo-CVG AFS was demonstrated by successfully analyzing a certified reference water sample and several mineral water samples.