Determination of Common Inorganic Anions by Ion Chromatography in Surfacewaters

A method for the determination of common inorganic anions (F-,Cl-,NO2-,NO3-,SO42-,PO43-) in surfacewaters by ion chromatography using directconductivity detection is proposed. Chromatographic separation of common inorganic anions in surfacewaters on a Ionpac AS11-HC anion exchange column (250 mm× 4 mm). Sodium hydroxide are used as eluent. The effects of the types of eluent,eluent concentration,column temperature and flow rate on separation and retention time of the anions are investigated. The optimized chromatographic conditions for the separation and determination of common inorganic anions are as follows:20.00 mmol/L sodium hydroxide as the eluent,column temperature of 18~ 25 ℃ and a flow rate of 1.0 mL/min. The detection limits(S/N=3) of six anions were in range of 0.055～0.61 mg/L. There lative standard deviations(RSD) of the concentrationare as for six anions are from 1.56% to 2.50% (n=3). The method is successfully applied to determinete other inorganic anions in ionliquids.