Comparison of Atomization Sources for a Field-Deployable Laser Optogalvanic Spectrometry System

Abstract

A field-deployable laser optogalvanic spectrometry (LOGS) system has been developed to measure the concentration of metal species present in the near-atmospheric pressure off-gases of mixed-waste thermal-treatment systems, where metal species occur primarily as airborne metal oxide and/or metallic particles rather than as free, single atoms. Atomization is required to simplify the analyte and facilitate the detection of low concentrations. A comparative study of different LOGS atomization sources (electric glow discharge, radio frequency discharge, flames) was performed with respect to the feasibility of deploying each source. The advantages and disadvantages of the various atomization sources are discussed in terms of real-time monitoring, ease of operation, and ruggedness for field deployment. Although the various atomization sources permit a wide variety of laboratory-based LOGS applications, it is concluded that a flame-based atomization source is best suited for a field-deployable LOGS system to monitor airborne metal species in near-atmospheric pressure off-gas systems. Flame-based LOGS systems are usually referred to as laser-enhanced ionization spectrometry systems.