The MS-MS spectra of m/z of 1,341 and 1,473 from B-3501 GXM and a m/z of 868 from I23 GXM. The fragmentation patterns show the loss of Man, GlcA, and Xyl from the ions, confirming the oligosaccharide composition. (A) A m/z of 1,341, singly charged ion; (B) m/z of 1,473, singly charged ion; (C) m/z of 868, doubly charged ion.