胶束电动毛细管色谱法测定板蓝根中苯甲酸、水杨酸和邻氨基苯甲酸

Determination of Benzoic Acid,Salicylic Acid and o-Aminobenzoic Acid in Radix Isatidis by Micellar Electrokinetic Capillary Chromatography

采用胶束电动毛细管色谱法对板蓝根中芳香酸类化合物苯甲酸、水杨酸和邻氨基苯甲酸进行了分离测定。电泳介质(pH 9.8)为20 mmol.L-1硼砂、30 mmol.L-1十二烷基硫酸钠、2 mmol.L-1β-环糊精和4%(体积分数)甲醇组成的混合溶液,以对-羟基苯甲酸为内标,分离电压为16 kV,检测波长为250 nm。在优化的试验条件下,苯甲酸、水杨酸和邻氨基苯甲酸的线性范围分别为40～240 mg.L-1,64～320 mg.L-1和40～400 mg.L-1,检出限(3S/N)依次为0.64,1.08,1.36 mg.L-1。应用此方法分析了板蓝根样品,测定回收率在93.3%～104.2%之间。

Micellar electrokinetic capillary chromatography （MECC） was applied to the separation and determination of aromatic acids, including benzoic acid, salicylic acid and o-aminobenzoic acid, in Radiz Isatldis. A mixed buffer solution of pH 9.8 containing 20 mmol · L ^-1 borate, 30 mmol ·L ^-1 SDS, 2 mmol· L ^-1 β-CD and 4% （by vol. ） methanol was used as the electrophoretic medium, p-Hydroxybenzoic acid was chosen as internal standard. Separation voltage applied was 16 kV and wavelength of detection was taken at 250 nm. Under the optimum conditions, linearity ranges of benzoic acid, salicylic acid and o aminobenzoic acid found were between 40- 240, 64-320 and 40-400 mg · L^-1 , with detection limits （3S/N） of 0. 64, 1.08, 1.36 mg · L^-1 respectively. The proposed method was used in the analysis of sample of Radix Isatidis, giving values of recovery in the range of 93.3%-104. 20%.