FIG. 4.

GC-MS spectra of individual perdeuteromethylated alditol acetate derivatives from serotype 16 OSE. The formation of prominent fragment ions is illustrated; fragments were assigned to 1,3,4,5-tetra-O-deuteromethyl-2-O-acetyl-6-deoxy-talitol (A), 2,4-di-O-deuteromethyl-1,3,5-tri-O-acetyl-rhamnitol (B), 2-O-deuteromethyl-4-O-methyl-1,3,5-tri-O-acetyl-rhamnitol (C), and 2,4-di-O-deuteromethyl-1,5-di-O-acetyl-3-2′-methyl-3′-O-deuteromethyl-4′-methoxy-pentanoyl-deuteromethylamido-3,6-dideoxy-hexitol (D).