1994 Volume 43 Issue 1 Pages 75-79
In non-suppressed ion chromatography with conductivity detection, a suspension of H-form cation exchange resin (SCR) was added to the eluate from the ion separating column. Sodium ions in the eluate were replaced by hydrogen ions, so that the background conductivity was reduced and anions were detected with higher sensitivity. The SCR was prepared as follows. A cation exchange resin (Amberlite IR-120B), converted into the H-form with hydrochloric acid, was ground with a millstone, and sieved to obtain the fraction which passes a 250 mesh screen. The powdered resin was suspended in water and left to stand for 2 h. The upper portion of the suspension was placed in a centrifuge tube and washed with water by centrifugation until the solution became neutral. An adequate amount of the collected fine resin was suspended in water at 0.20.5% concentration (6.315×10-3 meq/ml in ion exchange capacity). When the sodium hydrogen carbonate (1.7mM)-sodium carbonate (1.8 mM) solution was used as eluent at 0.8 ml/min and the SCR (8.2×10-3 meq/ml in ion exchange capacity) was added to the eluate at 0.8 ml/min, the background conductivity, originally 520 μS, was reduced to 15μS and 0.05 μg/ml of Cl-, 0.2 μg/ml of F-, NO2-, Br-, NO3-, PO43-and SO42-were able to be determined.
