The use of on-line ion chromatography for high temperature and high pressure reaction studies

This paper describes the use of on-line ion chromatography as a tool for chemistry reaction studies in small volume systems. The technique was used to study chemistry behavior in a high temperature and high pressure autoclave system. A dual analyzer, multi-channel on-line ion chromatograph (IC) was configured to automate the sampling and analysis. Analytical channels were set up for analysis of inorganic anions, monovalent cations, conductivity, and pH. Conductivity and pH were measured using the IC as a flow injection analyzer. Use of the IC system provides significant advantages over conventional sampling and analysis techniques: Reduction in sample volume, a closed sampling system that protects air or light sensitive analytes from breakdown, around-the-clock test performance combined with automatic calibration and quality control checking, and detection and tracking of reaction products or unexpected contaminants. Methods used to correct measured concentrations for the effects of sampling and for calculation of control chemical loss half-lives are presented. A limited evaluation of the flow injection analysis methods for conductivity and pH is provided