Liquid chromatographic retention behaviour in the separation of anti-epileptic drugs on phenyl-, diphenyl-, and triphenyl-bonded silicas and glasses.
The retention and selectivity behaviour of some anti-epileptic drugs were studied by high-performance liquid chromatography on 21 kinds of phenyl-modified porous glasses and silicas, prepared from solutions of phenyldimethylchlorosilane, diphenylmethylchlorosilane or triphenylchlorosilane in xylene, and from various kinds of glass or silica with various mean pore diameters and/or specific surface areas. From elemental analysis data for carbon, the maximum number of bonded phenyl surface groups per gram (mean pore diameter 15 nm, specific surface area 217 m2/g, pore volume 0.85 ml/g) in phenyl-, diphenyl-, and triphenyl-bonded gels was calculated to be 0.313, 0.159, and 0.112 X 10(21), respectively. Using various acetonitrile-0.01 M potassium dihydrogen phosphate mixtures as eluents, the anti-epileptic drugs were separated on all the gels studied, but with different degrees of resolution. With increase in specific surface area on the glasses or silicas, the k' values of three anti-epileptic drugs increased. The selectivity for the separation of carbamazepine and diphenylhydantoin is discussed and explained by the pi-pi interaction between solutes and stationary phases. It has been shown that diphenyl and triphenyl phases are more suitable stationary phases for the selective separation of anti-epileptic drugs than monophenyl phases.
D000927:Anticonvulsants / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D005898:Glass; D007202:Indicators and Reagents; D012822:Silicon Dioxide
D000927:Anticonvulsants; D007202:Indicators and Reagents; D012822:Silicon Dioxide