2-芳基丙酸类手性药物色谱拆分的热力学研究

以0.5%和1.0%(体积分数)正丙醇-50 mmol/L磷酸盐缓冲液(pH 6.41)为流动相,温度74~313 K,在Chiral-AGP柱手性固定相上,考察了萘普生和布洛芬对映体在手性柱上的保留和分离行为。在实验范围内,温度升高对分离不利,随着温度的升高,对映体的保留时间、分离度和选择性因子都减少;萘普生对映体的分离度均比布洛芬大;流动相含1.0％正丙醇时,萘普生对映体和布洛芬对映体达到完全分离应控制的最高温度分别为298和288 K。用ln k对1/T作图得到的Van’t Hoff曲线都具有良好的

Extra-thermodynamic Properties of 2-Arylpropionic Acids on a Chiral-AGP Column by High Performance Liquid Chromatography

The effect of temperature (274-313 K) on the chromatographic behavior of naproxen and ibuprofen on a Chiral-AGP column was investigated with a mobile phase consisting of 50 mmol/L phosphate buffer (pH 6.41) and 0.5% (or 1.0%, v/v) 1-propanol. Higher temperature was found disadvantageous to the enantiomeric separation. With temperature increased, the retention time, resolution and selectivity of the chiral separation were decreased. The resolution of naproxen was larger than that of ibuprofen in all cases. When naproxen and ibuprofen enantiomers were entirely separated by the mobile phase containing 1.0% 1-propanol, the maximum temperatures allowed were 298 K and 288 K, respectively. All of the Van' t Hoff plots of the In k vsrsus 1/T were found to have good linearity, with the correlation coefficients better than 0.99 in all cases. The thermodynamic parameters (changes of enthalpy, i. e., deltaH0, for the transfer of enantiomers from the mobile phase to the stationary phase and differences of enthalpy and entropy changes, i. e., deltaS,R deltaH0 and deltaS,R deltaS0) were calculated. In general, in the temperature range examined the enthalpic contribution to the overall enantiomer transfer energy was found to be more significant than the entropic one.