On-line concentration and separation of multiple derivatized monosaccharides from edible fruit with...

An on-line enrichment and separation of multiple derivatized monosaccharides with cyclodextrin-encapsulated sweeping (CDES) by micellar electrokinetic chromatography (MEKC) was presented. Five monosaccharides (L-(-)-Mannose, D-(+)-Glucose, D-(-)-Ribose, D-(+)-Xylose, and L-(+)-Rhamnose) were derivatized with 1-phenyl-3-methyl-5-pyrazolone, subsequently concentrated and separated by MEKC. The optimized conditions were as follows: 50 mM phosphoric acid (PA), 100 mM sodium dodecyl sulfate (SDS), and 30 % (v/v) methanol in background solution; 140 s injection of sample solution containing 50 mM CD and 100 mM PA, followed by 90 s injection of 40 mM SDS solution. Under the optimized conditions, the correlation coefficients ≥ 0.9953, and the limits of detection ranged from 4.2 to 7.4 ng/mL. Relative standard deviation values ranged from 0.24-4.23 %, and sensitivity enrichment factors were in the range of 53-82 compared with typical injection (50 mbar, 3 s). The CDES-MEKC method was successfully applied to Jujube with good recoveries of 84.22-104.33 %. The method provides new ideas for the on-line enrichment and detection of trace monosaccharides and even other target analytes in foods with complex matrices.