柱前衍生化高效液相色谱-荧光检测法测定桑叶中的1-脱氧野尻霉素

采用柱前衍生化高效液相色谱-荧光检测法测定了桑叶中的1-脱氧野尻霉素(DNJ)。用0.05 mol/L HCl提取桑叶中的DNJ,采用6-氨基喹啉基-N-羟基琥珀酰亚氨基甲酸酯(AQC)试剂在pH 8.5硼酸盐缓冲液下对DNJ进行衍生化,以0.02 mol/L磷酸二氢钾缓冲液(pH 5.0)-乙腈(体积比为85∶15)为流动相,利用C18色谱柱(5 μm,250 mm×4.6 mm)分离,在激发波长为250 nm、发射波长为395 nm条件下进行荧光检测,DNJ的AQC衍生物与衍生化试剂的水解产物分离良好。方法的线性范围为0.5～25 mg/L,检出限为0.02 mg/L（S/N=3）。实验测得桑叶中DNJ含量为0.12%;回收率为96.1%～98.6%。

Determination of 1-deoxynojirimycin in Morus alba L. Leaves using reversed-phase high performance liquid chromatography-fluorescence detection with pre-column derivatization

A rapid, reliable and suitable method for the determination of 1-deoxynojirimycin (DNJ) in Morus alba L. leaves has been developed. The DNJ in 100 mg dried leaves was extracted twice with 10 mL aqueous 0.05 mol/L HCl, then derivatized by 6-aminoquinoiyi-N-hydroxysuccinimidyl carbamate （AQC） in K3BO3 buffer （pH 8.5）, and analyzed using a high performance liquid chromatograph equipped with a fluorescence detector. The analyte was eluted with a mobile phase of 0.02 mol/L potassium dihydrogen phosphate buffer-acetonitrile (85∶15, v/v) at the rate of 1.0 mL/min. The derivatized DNJ was well dissolved from the hydrolysis products of AQC. The linearity ranged from 0.5 to 25 mg/L, and the detection limit was 0.02 mg/L （S/N=3）. The content of DNJ in Morus alba L. leaves was 0.12%, the recovery was 96.1%-98.6%.