A Miniaturized Glow Discharge Optical Emission Detector for Aqueous Analytes

Abstract

A miniaturized optical emission detector has been developed for use with aqueous samples. Stability and durability compared to previous devices were improved by further miniaturization of the sample inlet and a better design creating a more stable gas/liquid flow interface during operation. Sample introduction was achieved by using a technique in which the liquid sample is used as the cathode for the discharge. A pulsed HV DC supply was used to ignite the discharge between the flowing sample and a platinum wire anode. The discharge operates in air at close to atmospheric pressure and the detection of sodium has been demonstrated with the observation of an emission line at 589nm.