Alumina as stationary phase for ion chromatography and column-coupling techniques

Columns packed with alumina were combined with common anion-exchange columns and applied to the ion chromatographic determination of sulphate in brines and biological fluids and for the trace determination of iodide in mineral waters and fruit juice samples. Alumina was found to be a highly selective stationary phase for the preconcentration of sulphate from complex matrices. Further, owing to its selectivity, which is different from that of R4N+-type anion-exchange materials, it is well suited for on-line column-coupling techniques. In this way sample clean-up can be minimized, and the sensitivity of the chromatographic system allows determinations of iodide down to the low ppb range.