ORTHO-PHOSPHATE OF AROMATIC-AMINES AS THE INTERACTION REAGENTS IN REVERSED-PHASE HPLC CHROMATOGRAPHY - DIRECT SPECTROPHOTOMETRIC DETECTION OF NONABSORBING ANIONS

This paper shows that in the ion-interaction-reagent reversed-phase HPLC chromatography here employed anions too, like amines, are retained through the formation of ion-pairs and that under this form they are also released. Experiments were performed with spectrophotometric detection and with the use of interaction reagents composed by an anion which does not absorb at the detection wavelength and an amine which on the contrary does. The formation of the characteristic system peaks was discussed and explained, in agreement with previously obtained results. The method here developed permits the spectrophotometrical detection of non-absorbing anions, through the absorbance properties of the hetaeron amine.