Preparation, chromatographic evaluation and comparison of cystine- and cysteine-bonded stationary phases

In this paper, cystine- and cysteine-bonded stationary phases were synthesized and characterized by UV spectroscopy, Fourier transform infrared spectroscopy and elemental analysis which proved the successful immobilization of cystine and cysteine on the silica support. Both the new stationary phases displayed mixed-mode behavior, hydrophilic interaction chromatography (HILIC) mode and reversed-phase liquid chromatography (RPLC) mode. Retention behaviors of polar compounds on the two stationary phases were studied under different mobile phases by varying their water content, pH and ionic strength. The separation of sulfanilamide and substituted benzoic acid compounds was demonstrated on the new phases.