Simultaneous ion-exclusion/cation-exchange chromatography of anions and cations in acid rain waters on a weakly acidic cation-exchange resin by elution with sulfosalicylic acid.
A simple, selective, and sensitive method for the simultaneous determination of anions (sulfate, nitrate, and chloride) and cations (sodium, ammonium, potassium, magnesium, and calcium) in acid rain waters was developed using ion-exclusion/ cation-exchange chromatography with conductimetric detection. A weakly acidic cation-exchange resin column (Tosho TSKgel OA-PAK-A) and a sulfosalicylic acid-methanol-water eluent was used. With a mobile phase comprising 1.25 mM sulfosalicylic acid in methanol-water (7.5:92.5) at 1.2 ml/min, simultaneous separation and detection of the above anions and cations was achieved in about 30 min. Linear calibration plots of peak area versus concentration were obtained over the concentration ranges 0-1.0 mM for anions (R=0.9991) and 0-0.5 mM for cations (R=0.9994). Detection limits calculated at S/N=3 ranged from 4.2 to 14.8 ppb for the anions and from 2.4 to 12.1 ppb for the cations. The reproducibility of retention times was 0.14-0.15% relative standard deviation (RSD) for anions and 0.18-0.31% for cations, and reproducibility of chromatographic peak areas was 1.22-1.75% RSD for anions and 1.81-2.10% for cations. The method was applied successfully to the simultaneous determination of anions and cations in aerosols transported from mainland China to central Japan, as determined by a meteorological satellite data analyzer.
National Industrial Research Institute of Nagoya, Japan. ktanaka@nirin.go.jp
K
K
Tanaka
K
K
Ohta
P R
PR
Haddad
J S
JS
Fritz
D A
DA
Miyanaga
W
W
Hu
K
K
Hasebe
D000838:Anions / Q000032:analysis; D001557:Benzenesulfonates; D002411:Cation Exchange Resins; D002412:Cations / Q000032:analysis; D002852:Chromatography, Ion Exchange / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D015203:Reproducibility of Results; D012459:Salicylates / Q000737:chemistry*; D012680:Sensitivity and Specificity
D000838:Anions; D001557:Benzenesulfonates; D002411:Cation Exchange Resins; D002412:Cations; D012459:Salicylates; C003366:sulfosalicylic acid