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 Monts 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 Monts alba L. leaves was 0. 12%, the recovery was 96. 1% - 98.6%.