A rapid, accurate and precise method for the determination of 22 amino acids in Isatidis Radix by Hydrophilic Interaction Ultra-High-Performance Liquid Chromatography Coupled with Triple-Quadrupole Mass Spectrometry (HILIC-UPLC-MS/MS) was established. Chromatographic separation was carried out on a Acquity UPLC BEH Amide column (2.1 mm × 100 mm, 1.7 m) with gradient elution of acetonitrile (containing 0.05% formic acid and 2 mM ammonium formate) and water (containing 0.15% formic acid and 10 mM ammonium formate) at a flow rate of 0.4 mL/min; Waters Xevo TM TQ worked in multiple reaction monitoring mode. All components were separated in 17 min. All calibration curves were linear (R 2 > 0.991) over the tested ranges. The limits of detection (LOD) and limits of quantitation (LOQ) for these compounds were 0.21-79.55 and 0.72-294.23 ng/mL, respectively. The average recoveries were in the range of 93.75-104.16% with RSD value less than 6.56%. Therefore, this method could be an alternative assay for the determination of 22 amino acids in Isatidis Radix due to its rapidness, sensitivity, less sample and solvent consumption.

To establish an ultra-high performance liquid chromatography coupled with triple quadrupole mass (HILIC-UPLC-MS/MS) for determination of sixteen nucleosides and nucleobases in Isatidis Radix. Chromatographic separation was carried out on a Acquity UPLC BEH Amide column with gradient elution of acetonitrile (containing 0.1% acetic acid) and water (containing 0.8% acetic acid and 10 mmol L À1 ammonium acetate) at a flow rate of 0.3 mL min À1 , the column temperature was set at 35 C; Waters XevoÔ TQ worked in multiple reaction monitoring mode. Each component were separating in 11 min. All calibration curves were linear (r 2 > 0.997) over the tested ranges. The limits of detection of these compounds were 0.02-42.54 ng mL À1 . The limits of quantitation of these compounds were 0.05-98.18 ng mL À1 . The average recoveries were in the range of 93.81-105.77% with RSD value less than 7.5%. The result showed that almost all of these Isatidis Radix were rich in nucleosides and nucleobases, but their contents were obviously various. The method was simple and fast with high precision, sensitivity and repeatability, which can be used for determination of this type class of nucleosides and nucleobases in other medicinal herbs.