Objective: A monosaccharide derivative method with improved efficiency was developed through the addition of borax in the process of 1-penyl-3-methyl-5-pyrazolone(PMP) and p-aminobenzoic acid(PABA) derivatization. Method: The effect of borax on the derivative efficiency of 8 common aldoses with PMP

and ketose (fructose) with PABA was investigated. Derivative conditions such as the concentration of borax solution

temperature and time were optimized by capillary zone electrophoresis(CZE) method. The improved method was applied to the determination of monosaccharide composition of Adenophorae Radix polysaccharide. Result: The results showed that the addition of borax could enhance both the PMP and PABA derivative efficiencies during the monosaccharide derivatization

and the most significant improved efficiency belonged to glucose

which could be increased roughly 1.2-fold. The optimized conditions of aldoses derivatization with PMP were as follows:the concentration of borax solution was 6.86 mmol·L-1

the temperature was 70℃

and the time was 30 min; the optimized conditions of ketose derivatization with PABA were as follows:the concentration of borax solution was 20.43 mmol·L-1

the temperature was 70℃

and the time was 60 min. The application of the improved method to the determination of monosaccharide composition of Adenophorae Radix polysaccharide showed monosaccharide with lower content could be detected by the improved method while the original one failed. Conclusion: Therefore

it is an useful approach to improve the monosaccharide derivative efficiency and detection sensitivity by adding the borax to change the balance of conformations of monosaccharide

which makes the proportion of chain structure increased. The method is accurate

sensitive and simple

and provides technical support for the monosaccharide composition analysis and the evaluation of structure-activity relationship of polysaccharide from traditional Chinese medicines.