Two new types of boronate affinity solid phases were synthesized and characterized. The materials were prepared by silylation of porous silica gel with monochlorosilane derivatives containing synthetic sulfonyl-and sulfonamide-substituted phenylboronic acids. The new solid phases were evaluated for boronate affinity chromatography with aryl and alkyl cis-diol compounds, and found suitable for the retention of cis-diols under acidic conditions. Significant correlations between the retention factor (K) and the pH of the mobile phase demonstrate that the binding of cis-diols to the solid phases is best rationalized by chelation. Based on the low ionization constant, caused by the electron-withdrawing effects of the sulfonyl and sulfonamide groups, these media display an enhanced affinity for cis-diols as compared to unsubstituted phenylboronic acid. Utilizing Isocratic elution, a mixture of various biologically relevant L-tyrosines, L-DOPA and several catecholamines were resolved with a mobile phase composed of 0.05 M, pH5.5 phosphate buffer. Mono-, di-and triphosphates of adenosine were also separated at pH 6.0. Hence, the new boronate solid phase offers efficient affinity separation and purification of cis-diol containg molecules under rather mild pH regions.

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