Ion chromatographic determination of acidity

The practice of determining acid concentrations by titrations has remained unchanged for more than a century. We introduce a new approach to the deter mination of acid concentrations based on cation exchange chromatography, We demonstrate the ability of sulfonated styrenedivinylbenzene based stationa ry phases to separate the hydrogen ion from other monovalent cations, The e luent is a dilute solution of a neutral salt, sometimes containing a small concentration of the corresponding acid, e.g., sodium ethanesulfonate, pH a djusted with ethanesulfonic acid, The high equivalent conductance (similar to 350 S.cm(2)/equiv) of H+ and relatively low eluent concentration allows sensitive conductometric detection of H+, down to the 50 mu M level under f avorable conditions, The conductometric response to H+ can be linear over a wide range of H+ concentrations, from snb-millimolar to several molar conc entrations, The system allows the rapid quantitation of strong acids; weak, acids can also be determined depending on pK(a) and injected concentration , The determinations of several strong and weak acids are presented along w ith factors that govern their chromatographic analysis.