- for HILIC of Complex Carbohydrates-
This neutral material has the unusually high capacity needed to retain complex carbohydrates in the HILIC mode. Columns can frequently be operated with just acetonitrile and water, although charged carbohydrates may require inclusion of some salt such as ammonium acetate. These conditions are convenient for isolation of carbohydrates or direct flow to a mass spectrometer. Selectivity is good for both native glycans and derivatives such as those with the 2-aminopyridine (PA-) fluorophore. Oligosaccharide mixtures can often be resolved isocratically, although gradients are recommended for especially varied samples. Sialylated and asialo- glycans can be resolved using the same running conditions. In some cases selectivity compares favorably with that of HPAEC with PAD detection, and both running conditions and equipment maintenance are far more convenient.