NEW APPROACH FOR CONTROLLING THE PARTITIONING OF ANALYTE IONS IN ION CHROMATOGRAPHY WITH A WATER MOBILE-PHASE

The problem of the ''confusing'' distribution of analyte ions in quant itative analysis using ion chromatography with a water mobile phase (w ater mobile-phase ion chromatography, WMP-IC) has been overcome. Hence , the number of possible applications of ion chromatography using wate r as the mobile phase is vastly enhanced. In previous WMP-IC studies o f inorganic ions, each analyte cation and/or anion species was distrib uted to each counterion species and co-eluted as ion pairs. Such a par titioning of the analyte ions hampers their quantitative analysis beca use calibration graphs must be derived for all possible ion pairs. Thi s paper deals with a simple and convenient method to obtain an ''exclu sive'' partitioning, i.e. where each analyte ion species exists in onl y a single ion pair. This was achieved by the addition of specific ion s to the sample solution to regulate the number of species and the con centration ratio of the ions in the sample solution. ''Exclusive'' par titioning of the analyte ions and their precise detection have been re alized.