CHROMATOGRAPHY, Vol. 35 (2014), No. 1, pp. 31-39
Focusing Review
Development and Pharmaceutical Applications of Functional Stationary Phases for Capillary Electrochromatography and Chiral Separation
Kaname Ohyama
Graduate School of Biomedical Sciences, Nagasaki University,
1-14 Bunkyo-machi, Nagasaki, Nagasaki 852-8521, Japan
We synthesized 3-(4-sulfo-1,8-naphthalimido)propyl-modified silica (SNAIP) for capillary electrochromatography (CEC). The unique structure of SNAIP contributed to the retention by three interactions including hydrophobic, electrostatic and π-π interactions and the acceleration of electroosmotic flow at an acidic condition. The CEC employing SNAIP was successively applied to the rapid separations of several drugs, peptides and polar compounds. Also, several examples for applying CEC to real sample analyses were demonstrated. Furthermore, with the idea to use adamantane as a shield to reduce the peak tailing of charged solutes in CEC, adamantyl (ADM)-functionalized polymer monolith by a single-step copolymerization with the monomer containing ADM structure and a cross-linker was presented. Three chiral stationary phases with different phenylalanine (Phe) peptide lengths, Phe4, Phe8, Phe12, were prepared to study the effect of peptide length on enantioseparation in reversed-phase HPLC. The highest resolution was observed for the selector with intermediate peptide length (i.e., Phe8). The side chain of amino acids was also found to play a role for the separation performance of the chiral stationary phases (CSPs). The IR spectra suggested that the Phe peptides immobilized on the CSPs were assumed to be mainly in theα-helical state. Also, it was found that the conformation strongly contributed to the chiral recognition of the CSPs by thermodynamic study.
Keywords: Capillary electrochromatography, Chiral separation, Stationary phase.
Received: 9 January 2014
Accepted: 26 January 2014