溶质在动态改性氧化锆液相色谱柱上的保留行为

Retention Behavior of Solutes on Liquid Chromatographic Column Packed with Dynamically Modified Zirconia

分别采用硬脂酸、环糊精和十二烷基磺酸钠动态改性自制的ZrO2微球，研究了流动相中甲醇和改性剂浓度对苯酚及苯甲酸的衍生物、苯胺衍生物及芳香烃类化合物的色谱保留行为的影响。中性及碱性化合物的保留时间较短，色谱峰对称；酸性化合物保留时间较长，色谱峰拖尾较严重。改性氧化锆表现出反相色谱性能。

Zirconia was dynamically modified with stearic acid, β-cyclodextrin and sodium dodecylsulfonate,separately, to form liquid chromatographic packings. The chromatographic behaviors of aromatic hydrocarbons, acidic compounds (phenol, nitrophenols and benzoic acids ) and basic compounds (aniline,nitroanilines and toluidines ) were investigated on these modified zirconia packings with a mixture of methanol/water as the mobile phase. On stearic acid modified zirconia, aromatic hydrocarbons and the basic compounds exhibit symmetrical peaks. The retention time of these solutes decreases with increasing the concentration of methanol in the mobile phase. When the mobile phases with stearic acid were used, the retention time of these solutes has a maximum with variation of stearic acid concentration (0-1. 0 mmol/L) in the mobile phase. However, the acidic compounds such as nitrophenols and benzoic acids are strongly adsorbed and can not be eluted from the column with the mobile phases. No leaking of stearic acid on the modified zirconia was found after 3000 column volumes of the methanol/water mobile phase were used. The results showed that the stearic acid modified zirconia can be used as a stationary phase for reversed-phase liquid chromatography. On β-cyclodextrin modified zirconia, aromatic hydrocarbons and basic compounds exhibit shorter retention time than those on the stearic acid modified zirconia under the same mobile phase composition, however, nitrophenols can be eluted but give unsymmetrical peaks. On sodium dodecylsulfonate modified zirconia packings, the basic compounds can not be retarded；Aromatic hydrocarbons and acidic compounds exhibit short retention time. The results can be ascribed to the weak adsorption of sodium dodecylsulfonate on the zirconia.