High-efficiency photooxidation vapor generation of osmium for determination by inductively coupled plasma-optical emission spectrometry

Abstract

A high-efficiency photooxidation vapor generation (POVG) method for the determination of osmium in water by inductively coupled plasma-optical emission spectrometry (ICP-OES) has been developed. Osmium is readily converted to volatile osmium tetraoxide in plain (neutral) water medium by simply exposing to UV irradiation, enabling fast and effective generation without the use of any chemical oxidizing agents. An optimum generation efficiency of 96.1% was achieved by the use of a home-made high efficiency photooxidation UV reactor. The influences of the background matrices, sample flow rate, carrier gas flow rate, and heating temperature were investigated. Under optimized conditions, a limit of detection (LOD) of 0.2 ng mL⁻¹ was obtained with the proposed POVG method. A precision of 1.3% (RSD, n = 6) was achieved at a concentration of 2 μg mL⁻¹. The method is simple, rapid, free of contamination, and not subject to severe interferences. It provides a novel approach to the generation of Os vapor from water samples in a green manner.