Determination of total gaseous selenium in atmosphere by honeycomb denuder/differential pulse cathodic stripping voltammetry

Abstract

A new analytical method has been developed for the determination of total gaseous selenium in the atmosphere by honeycomb denuder collection followed by differential pulse cathodic stripping voltammetry (DPCSV) measurement. Gaseous selenium was collected in a denuder coating solution containing 2% HNO 3 and 2% glycerine. The soluble product, selenious acid, was then extracted by water for DPCSV analysis. The collection efficiency for gaseous selenium was 99.1% at a flow rate of 1 l min −1 for 3 h. Excellent linearity in DPCSV was maintained up to Se concentration of 40 ng ml −1. This was equivalent to a working concentration of 220 ng m −3 of selenium in the atmosphere. A precision of 1.26% RSD ( n=5) for 5 ng Se was obtained, and the detection limit (3 σ) and the quantitative determination limit were estimated to be 0.96 and 3.19 ng m −3. The average recovery of selenium in three standard samples prepared by independent digestion of NIST SRM 1648 (Urban Particulate Matter) using our analytical system was 99.0%. The total content of gaseous selenium in the atmosphere of our laboratories was 3.2–4.4 ng m −3.