Ion chromatographic determination of organic acids and cations via exchange columns connected in parallel

A column switching technique has been developed for the sequential determination of organic acids and cations in alcoholic drinks. An anion-exchange column and a cation-exchange column were connected in parallel for the measurement. Oxalic acid was employed as a common eluent for both the anion- and cation-exchange columns. Under the same chromatographic conditions, the organic acids and cations can be separated sequentially by a switching operation selecting the path way through the anion-and cation-exchange columns. This method is simple to operate and is very sensitive with detection limits of 0. 1 1. 0 mg/L for organic acids and 10 ~ 20 μg/L for cations.