Ultrasensitive fluorometric detection of carbohydrates as derivatives in mixtures separated by capillary electrophoresis.

Reducing monosaccharides and oligosaccharides, after reductive amination, were separated and detected as their 3-(4-carboxybenzoyl)-2-quinolinecarboxaldehyde (CBQCA) derivatives by capillary electrophoresis/laser-induced fluorescence. Under optimized conditions, the minimum detectable quantities for monosaccharide solutes were assessed at low attomole levels (0.5 amol for the CBQCA derivative of galactose). The system has shown considerable promise for high-sensitivity analysis of both neutral and amino sugars in glycoproteins. Complex oligosaccharides, isolated from bovine fetuin by hydrazinolysis, were also successfully "mapped."