Simultaneous Determination of Anions and Cations in Sewage Water by Ion Chromatography with Dual-Flow Path System

A simultaneous determination method of anions and cations in sewage water by an ion chromatographic method using a dual flow path system has been investigated. This analytical method provides a high linearity of the calibration curve as well as repeatability and reproducibility. The correlation coefficients of the calibration curve were estimated to be from 0.9980 to 0.9999 for anions and cations in the low concentration range from 0.1 mg L-1 to 2.0 mg L-1. The detection limits by an EC detector calculated on 3σ were 0.01 mg L-1 for F-, 0.01 mg L-1 for Cl-, 0.02 mg L-1 for NO2-, 0.02 mg L-1 for Br-, 0.02 mg L-1 for NO3-, 0.02 mg L-1 for PO43-, 0.01 mg L-1 for SO42-, 0.01 mg L-1 for Li+, 0.01 mg L-1 for Na+, 0.01 mg L-1 for NH4+, 0.03 mg L-1 for K+, 0.01 mg L-1 for Mg2+, and 0.01 mg L-1 for Ca2+. In addition, the detection limits by UV detector calculated on 3σ were 0.02 mg L-1 for NO2-, 0.02 mg L-1 for Br-, and 0.01 mg L-1 for NO3-. These analytical methods could be successfully applied to the determination of anions and cations in inlet water of sewage water.