Analysis of Mono-, Di- and Oligosaccharides by CE Using a Two-Stage Derivatization Method and LIF Detection.

A sensitive CE with LIF method has been developed for quantitative analysis of small carbohydrates. In this work, 17 carbohydrates including mono-, di- and oligosaccharides
were simultaneously derivatized with 4-fluoro 7-nitrobenzo furazane (NBD-F) via a twostep reaction involving reductive amination with ammonia followed by condensation with NBD-F. Under the optimized derivatization conditions all carbo-hydrates were successfully derivatized within 2.5 h and separated within 15 min using borate buffer (90 mmol/L, pH 9.2). For sugar standards LODs were in the range of 49.7 to
243.6 nmol/L. Migration time and peak area reproducibility were better than RSD 0.1 and 3%, respectively. The method was applied to measure sugars in nanoliter volume samples of phloem sap obtained by stylectomy from wheat and to honeydew samples obtained from aphids feeding from wheat and willow.