Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry of N-Linked Carbohydrates and Related Compounds

Fig. 1. Positive ion MALDI mass spectrum of N-linked glycans released from chicken ovalbumin (Sigma grade VI, containing other glycoproteins) by hydrazinolysis and recorded from 2,5-DHB with a delayed extraction, reflectron-TOF mass spectrometer. Structures of the constituentglycans are listed in Table 1. The inset shows an enlargement of one of the peaks with its accompanying MK+, [M + 41J+ and [M + 42J+ ions. The [M + 41J+ ion is produced by the N-acetyl-glycosylamine, whereas the [M + 42J+ ion is caused by a mono-O-acetyl derivative. Peaks in the mlz 1400 region correspond to acetyl-hydrazides and the potassium adducts of the [M + 41J+ and [M + 42J+ ions.