The Application of a Calomel-based Chloride Electrode to the Continuous On-line Measurement of μg/1 Concentrations of Chloride in High-purity Waters

摘要

The development of a continuous on-line analyzer for the determination of μg/1 levels of chloride in high purity waters is described. The use of a solid state chloride electrode based on Hg/Hg_2Cl_2 permits the monitoring of 1-50 yg/1 chloride with a linear response of 0.4 mv/μg/1. Sample treatment consists of addition of formic acid by diffusion into the sample and cooling of the sample stream to 5°C. The system has no moving parts, requires calibration once a month, and reagent replacement every three months. This low level of maintenance and down-time should make this instrument useful in the control of chloride contamination in boiler water and other high purity process waters.