Homogeneous catalysis for photochemical vapor generation for speciation of inorganic selenium by high performance liquid chromatography-atomic fluorescence spectrometry

Abstract

A simple, sensitive and cost-effective homogeneous catalysis photochemical vapor generation (PVG) system for HPLC separation and atomic fluorescence spectrometry detection was reported herein for the speciation analysis of trace Se(IV) and Se(VI). Homogeneous Cd ions as a catalyst were stable and reliable, without complex nanomaterial synthesis and coating. Under the conditions of 60 μg mL⁻¹ Cd ions, 3.5 m reaction coil, 40% acetic acid and 0.30 mL min⁻¹ of 5 mM Na₂CO₃–1.3 mM NaHCO₃, the online HPLC-Cd-PVG-AFS system enabled us to achieve a calculated detection limit of 0.16 and 0.21 ng mL⁻¹ for Se(IV) and Se(VI), respectively. Moreover, it could also work successfully even in a phosphate separation system. Under the optimized conditions of 60 μg mL⁻¹ Cd ions, 5 m reaction coil, 40% acetic acid and 0.35 mL min⁻¹ of 50 mM Na₂HPO₃, a detection limit of 0.49/0.78 ng mL⁻¹ for Se(IV)/Se(VI) was achieved.