Objective: To establish an analysis method for direct detection of monosaccharide compositions of Ephedrae Radix et Rhizoma polysaccharide by HILIC-LC-MS/MS. Method: The separation was performed on ACQUITY UPLC BEH Amide column (2.1 mm×100 mm

1.7 μm) with 95%acetonitrile (A)-95% water (B) as the mobile phase for gradient elution (0-10 min

92%-70% A; 10-10.1 min

70%-92% A; 10.1-15 min

92%A) at a flow rate of 0.2 mL·min-1. The injection volume was 2 μL

and the column temperature was 60℃. In mass spectrometry

electrospray ion source was used:multiple reaction ion monitoring mode (MRM) under the negative ion. Turbo V ion source parameters were common to all analytes

as follows:the capillary voltage was -4.5 kV

and the source temperature was at 550℃. The curtain gas and collision gas setting were 30 psi and 10 psi

respectively. The pressure for nebulization gas and vaporization gas setting were 55 psi. The entrance potential (EP) and collision cell exit (CXP) were all -10 V. Result: Eight monosaccharide components were separated clearly within 12 min. The RSD values of precision

stability and reproducibility were all less than 2.1%. The average recoveries were 99.3%-102.5%

with RSD of 1.5%-2.9%. The developed method has been successfully applied to determine the major saccharides in 5 Ephedra Radixet Rhizoma polysaccharide samples. It was clear that the predominant composition monosaccharide in Ephedra Radixet Rhizoma polysaccharides were Rha

Ara

Man

Gal and GalUA. Conclusion: The established method for determination of the eight monosaccharides is stable

reliable

accurate

and reproducible

its sample pre-treatment is simple

without derivatization

and can be used for rapid detection of monosaccharide compositions in plant polysaccharide.