Quantitative ion chromatography with an ultraviolet absorbance detector without standards

Samples of ions are studied by non-suppressed ion chromatography and an ultraviolet absorbance detector. When two eluents of similar properties but different absorptivities per normal concentration are used in succession, two distinct chromatograms are obtained for the same sample. This information can be used to predict the number of equivalents of each ion present, as well as its absorptivity. In conjunction with elution-time studies, molar concentrations can also be obtained. The procedure does not require knowledge of the identity or any physical properties of the ionic species, and is applicable to ions with arbitrary absorption strengths.