毛细管区带电泳对羟基苯甲酸三种异构体的分离研究

Research on separation of three isomers of hydroxybenzoic acid by capillary zone electrophoresis

考察了邻羟基苯甲酸、间羟基苯甲酸和对羟基苯甲酸在毛细管区带电泳分离时的行为。研究了缓冲液pH、浓度和分离电压对三种羟基苯甲酸异构体分离的影响，结果表明在10mmol／L Na2HPO4缓冲体系（pH 10．15），运行电压25kV，实验温度25℃的分离条件下，采取压力进样（3．4kPa×3s），检测波长210nm；3种异构体在7min内获得基线分离。邻羟基苯甲酸、间羟基苯甲酸、对羟基苯甲酸在2-100μg／mL范围内，峰面积与质量浓度具有较好的线性关系，检出限分别是0．96，1．27和1．07μg／mL。

Separation of three hydroxybenzoic acid isomers by capillary zone electrophoresis was investigated. The effects of running buffer concentration, buffer pH and applied voltage on the separation of three isomers were disscused. The isomers of hydroxybenzoic acid were baseline separated within 7 min under the following separation conditions： 50 cm uncoated fused silica capillary, 10 mmol/L phosphate buffer （pH 10.15） as running buffer, 25 kV separation voltage. A linearity with UV detection exists between peak area and mass concentration of hydroxybenzoic acid isomers in the range of 2- 100μg/mL, and the detection limit of o-hydroxybenzoic acid is 0.96 μg/mL, m-hydroxybenzoic acid 1.27μg/mL and p-hydroxybenzoic acid 1.07μg/mL, respectively.