Determination of inorganic anions in Oligocene waters by ion chromatography

Concentrations of F–, Cl–, Br–, NO-3 –, PO-4 exp.3 and SO4exp. 2– in Oligocene water samples taken from 10 wells in the Warsaw area were determined. The wells were randomly chosen to get data representative for all the major districts ofWarsaw and the sampling was repeated in 3 weeks interval. Concentrations of anions in the examined water samples were determined by ion chromatography (IC Metrohm System with conductometric detection, Metrohm Metrosep A Supp 5 anion separation column and a mixture of 3.2 mmol/l Na2CO3 and 1.0 mmol/l NaHCO3 as an eluent). The detection limits of the determined anions were in the range from 0.06 mg/l (PO4exp.3–) to 0.39 mg/l (NO3–). The accuracy of the method used was evaluated by determination of spike recoveries of analytes introduced to the examined water samples and analysis of reference material containing a mixture of the determined anions (water matrix). The concentrations of particular anions determined in the examined water samples match acceptable levels as specified by drinking water regulations