Acid-rain monitoring in East Asia with a portable-type ion-exclusion–cation-exchange chromatographic analyzer

Abstract

A monitoring system consisting of a portable-type conductimetric ion-exclusion–cation-exchange chromatographic (CEC) analyzer and a meteorological satellite data analyzer has been investigated for the evaluation of the effects of acid precipitation on natural and urban environments in East Asia. The portable ion-exclusion–CEC analyzer uses a polymethacrylate-based weakly acidic cation-exchange resin column in the H+-form and a weak-acid eluent (tartaric acid–methanol–water) and is applied for the simultaneous determination of anions (SO42−, NO3−, and Cl−) and cations (Na+, NH4+, K+, Mg2+, and Ca2+) in precipitation transported from mainland China to central Japan, as mapped by the meteorological satellite data analyzer. Linear calibration graphs of peak area versus concentration for anions and cations were observed in the concentration range 0–1.0 mM for the anions and 0–0.5 mM for the cations. Detection limits at a signal-to-noise ratio of 3 were in the range 5.18–12.1 ppb for the anions and 6.58–16.5 ppb for the cations. The practical utility of this monitoring system is presented.