DIRECT DETERMINATION OF SODIUM, POTASSIUM, MAGNESIUM, AND CALCIUM-IONS IN HUMAN SALIVA BY ION CHROMATOGRAPHY USING A TAURINE-CONJUGATED BILE-SALT MICELLE-COATED STATIONARY-PHASE

Ion chromatography using a taurine-conjugated bile salt micelle-coated stationary phase has been investigated for the direct determination o f common metal ions in biological samples. Taurine-conjugated bile sal t micelles are reversed aggregates, where the negative charges of sulp honate form the inside of the micelle. The sulphonate charges are acti ng as the ion-exchange sites for the separation of cations, while the cavity of the helical micelle also acts as a size-exclusion site for t he rapid elution of large organic compounds. The combination of ion-ex change and size-exclusion functions provide a new model for the direct determination of inorganic species in biological fluids using ion chr omatography. The present system was successfully used for the direct d etermination of sodium, potassium, magnesium and calcium ions in human 's mixed saliva.