High-performance ion-exclusion/cation-exchange chromatography of anions and cations in acid rain waters on a weakly acidic cation-exchange resin

A new method for the simultaneous determination of anions (sulfate, nitrate , and chloride) and cations (sodium, ammonium, potassium, magnesium, and ca lcium) in acid rain waters was investigated using high-performance ion-excl usion/cation-exchange chromatography with conductimetric detection on a sep aration column packed with a polymethacrylate-based weakly acidic cation-ex change resin in the hydrogen-form and an eluent comprising 1.5 mM sulfosali cylic acid-6 mM 18-crown-6 at pH 2.6, operated at 1.5 ml/min. Effective sep aration and highly sensitive conductimetric detection for the anions and th e cations was achieved in about 14 min. Since the ionic balance (equivalent s of anions/equivalents of cations) of acid rain waters of different pH (4. 40-4.67) ranged from 0.97 to 0.94, evaluation of the water quality of acid rain was possible. This method was successfully applied to the simultaneous determination of the anions and the cations in acid rain transported from mainland China and North Korea to central Japan monitored by a meteorologic al satellite data analyzer. (C) 2001 Elsevier Science B.V. All rights reser ved.