FIG. 7.

GC-MS total ion chromatographs of the PMAAs derived from the trideuteriomethyliodide methylation of the CE3 and CE367 O-chain polysaccharides. The PMAAs of the glycosyl residues are as follows. Peak 1, terminally linked 3-O-methyl-6-deoxytalose; peak 2, 2,3,4-tri-O-methylfucose; peak 3, 3-linked fucose (and 3-linked 2-O-methylfucose); peak 4, 3,4-linked fucose (and 3,4-linked 2-O-methylfucose); peak 5, 3-linked mannose; peak 6, terminally linked glucuronic acid; peak 6*, a small amount of terminally linked glucuronic acid mixed in with some non-carbohydrate material; peak 7, 4-linked glucuronic acid; peaks a, undermethylated 3-O-methyl-6-deoxytalosyl residues; peaks b, undermethylated fucosyl residues; peak c, a small amount of galacturonic acid presumably due to slight contamination of the O antigen with core oligosaccharides; peaks ∗, non-carbohydrate contaminants from the derivatization process.