SEPARATION OF SULFONIC-ACIDS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY (HPLC) .1. BENZENESULFONIC ACIDS

The conditions for the separation of benzene monosulphonic acid and the three isomers of benzene disulphonic acid were investigated with high performance liquid chromatography (HPLC). Optimization was obtained by variation of the mobile phase so that a complete separation of the 4 components is possible in about 5 min. In all cases the stationary phase was silica gel chemically modified with octadecyl trichlorosilane and the mobile phase was a water-methanol mixture, to which tetraalkylammonium salts and sodium sulphate were added. The separation behaviour possibly shows that an ion-exchange mechanism and also an ion-pair mechanism are responsible for the interaction between substrate and stationary phase. The selectivity of the system could then be contributed primarily to ion-pair formation. © 1979 Springer-Verlag.