Determination of Inorganic Anions in Eucheuma cottonii and Carrageenan by Suppressed Ion Chromatography

Abstract

Inorganic anions in Eucheuma cottonii (a species of red algae) and carrageenan were determined by ion chromatography with a packed-column suppressor system. Two packed-column suppressors were connected in series via a 10-port switching valve for continuous chromatographic runs. Sodium carbonate-bicarbonate solution was used as the mobile phase and its background conductivity was reduced significantly by the suppressor, leading to achievement of lower detection limits. F^–, Cl^–, Br^–, NO₃^–, HPO₄^2-, SO₄^2- and I^– contained in Eucheuma cottonii and carrageenan were determined within 15 min. The detection limits obtained by the present method were 2.7-12 nM for these anions.