On‐capillary fluorescent labeling of saccharides for capillary electrophoresis

Abstract

The feasibility of on-capillary derivatization of saccharides by aromatic aminebased fluorescent labeling agents was tested. To avoid the problematic evolution of gaseous hydrogen cyanide, the Schiff base reduction by sodium cyanoborohydride, as the second step of the standard reductive amination protocol, was omitted. Glucose was used as a model analyte and 7-amino-1,3-naphthalenedisulfonic acid as the labeling agent. Our experiments showed that the direct reaction of the saccharide with the labeling agent in 2.5-M acetic acid yields a labeled product that is sufficiently stable to be separated from the labeling agent in 20-mM phosphate buffer, pH 3.5, and detected using UV detection. The glucose and label zones were introduced separately into the capillary and mixed using a negative voltage. Mixing voltage, its duration, the concentration of acetic acid in the reaction zone, and the waiting time between mixing and separation were optimized. To show the applicability of the procedure to a broader range of analytes, a mixture of different types of saccharides, that is, xylose (pentose), fucose (hexose), glucose (hexose), N-acetylglucosamine (N-acetylaminosaccharide), and lactose (disaccharide), was subjected to derivatization and analysis under the optimal conditions. The linearity and repeatability of the process were evaluated as critical parameters for its analytical applications. Six-point calibration dependences in the 1-50 mM range showed excellent determination coefficients of 0.9992 or higher for all five saccharides tested. The repeatability of the labeled saccharide peak areas was between 2.2% and 4.3%.

Establishment and application of characteristic degradation fingerprint for the quality control of Compound Banlangen Granules polysaccharides

“…Compared with ultraviolet spectroscopy, infrared spectroscopy, and high-performance liquid chromatography, capillary electrophoresis has the advantages of high column efficiency, large peak capacity, and simple sample pretreatment. For many years, capillary electrophoresis has been widely used in sugar analysis [18][19][20][21][22]. Zhang et al [23] used glycation enzyme to remove the excipient dextrin in Banlangen Granules, established a fingerprint of partial degradation products of polysaccharide in Banlangen Granules by capillary zone electrophoresis (CZE), and evaluated the quality of preparations from different manufacturers on the basis of polysaccharides and its partial degradation products by cluster analysis.…”

“…Compared with ultraviolet spectroscopy, infrared spectroscopy, and high‐performance liquid chromatography, capillary electrophoresis has the advantages of high column efficiency, large peak capacity, and simple sample pretreatment. For many years, capillary electrophoresis has been widely used in sugar analysis [18–22]. Zhang et al.…”