The absolute configuration of neutral monosaccharides, 2-acetamido-2-deoxy sugars, and uronic acids can be determined by capillary g.l.c. on SE-30 after glycosidation with (-)-2-butanol and protection of the remaining polar groups. The method is illustrated by application to mixtures of the constituent sugars of the capsular polysaccharide from Klebsiella type 57, alpha 1-acid glycoprotein, mucus glycoproteins, and the methylated, acidic polysaccharide from the coccoliths of Emiliania huxleyi (Lohmann) Kamptner.