Separation of inorganic anions and carboxylic acids using sulfonic acids as eluents

Separation of inorganic anions and weak acids in a non-suppressed ion chromatography was investigated. A number of sulfonic acids were examined as eluents using simultaneous UV absorption and conductivity detection. Ion-exchange separation was conducted on a low capacity anion exchange column. Methane-, ethane-, camphor-, naphthalene- and toluene sulfonic acid and octane sulfonate the eluents employed. Retention of the inorganic anions was determined by their ion-exchange selectivities relative to the ion-exchange selectivity of the eluents and the eluent concentration. For a given inorganic anion, as the eluent selectivity or its concentration increased, retention decreased. A plot of log capacity factor versus eluent concentration for each anion studied yielded a linear plot. Detection-limits were in the range of 1-100 ppm for both conductivity and UV absorption detection. (author)