Objective: To establish a HILIC-UPLC-MS/MS for determination of 11 nucleosides and nucleobases in Ziziphi Spinosae Semen. Method: Acquity UPLC BEH Amide (2.1 mm×100 mm

1.7 μm) was adopted as chromatographic column

with Amide 1.7 μm VanGuard as the guard column; the mobile phase consisted of acetonitrile (containing 0.1% acetic acid) and water (containing 0.8% acetic acid and 10 mmol·L-1 ammonium acetate) at a flow rate of 0.3 mL·min-1; the temperature was set at 35℃; sample size was 1 μL. Waters XevoTM TQ worked in MRM mode. Result: The Tested components were separated in 7 min. All calibration curves were linear (r>0.992 2) within the tested range between 0.002 32-8.66 mg·L-1. The average recoveries ranged from 92.15% to 108.23%

with RSD value below 7%. The contents of these batches of nucleosides and nucleobases were obviously different. The mass fraction of all of the target compounds ranged between 24.5-48.48 μg·g-1. Sample No. 10 had the lowest content

while sample No. 2 had the highest content. Uridine was found to be the highest content in all samples (mean:14.84 μg·g-1). Furthermore

the content of thymidine was observed to be lower than others in all markers (mean:0.14 μg·g-1). Conclusion: The method was simple and fast

with a high precision

sensitivity and repeatability

which can be used for qualitative and quantitative analysis for nucleosides and nucleobases in Semen Ziziphi Spinosae.