Application and validation of ion chromatography for the analysis of power plants water: Analysis of corrosive anions in conditioned water–steam cycles

Abstract

In this study, the possibility of monitoring ion species that could cause corrosion processes in the thermal power plant (TPP) using suppressed ion chromatography (SIC) was investigated. An ion chromatography method for the determination of target anions at sub-to-low-μg/L levels in power plant water samples was developed. In this method, the water samples are injected using the large-loop direct injection technique, the analyte anions are separated and detected using the suppressed conductivity detection method. The validation of the analytical method was studied in terms of linearity, sensitivity, precision and accuracy. The method was linear (r>0.995) over the concentration working range. The detection limits were found to be 0.080, 0.160, 0.180, 0.230 and 0.200μg/L for F−, Cl−, NO3−, PO43− and SO42−, using Na2CO3/NaHCO3 as the eluent, and 0.077 and 0.082μg/L for F− and Cl− using NaOH as the eluent, respectively. The relative standard deviations (RSD) of the retention times and peak areas were less than 0.8 and 8%, respectively. The derived data showed that the average recoveries were generally in the range of 60–120%. The performance of the new method was evaluated by analyzing water–steam samples from the thermal power plant “Nikola Tesla”, Serbia.