Methylation analysis in glycoprotein chemistry: low- bleeding columns for the gas chromatographic analysis of methylated sugar derivatives

Columns packed with 0.3–0.4% OV-225 on Chromosorb surface modified wit high-molecular-weight polythylene glycol have been developed for the gas chromatographic analysis of methylated sugar derivatives. These columns provided a better separation of O-acetyl-O-methylmannitols and -galactitols than those usually employed (packed with 3% ECNSS-M or 3% OV-225) and an exceptionally good resolution of O-trimethylsilyl(TMS)-O-methylalditols. Methylated derivatives of glucosamine could be chromatographed well both in the form of N,O-acetylgluco- saminitols and as the corresponding N-acetyl-O-TMS derivatives. Short retention times make it possible to perform analyses rapidly and at temperatures 40–50° lower than the upper operation limit of the packing (ca. 250°). Column bleeding is negligible, thus ensuring that the retention parameters are constant for long-term functioning of the column.