However, especially the spectra of larger oligosaccharides were characterized by multiple signals (double / triple charge quasimolecular and fragment ions) and significant source fragmentation (cleavage of sulfate). Therefore, only the later eluting small double peak at 16 min was identified as κ-carrahexaose, whereas the other peak could not be assigned to a specific structure. In the κ-carrageenase hydrolysate of IC1, trace amounts of κ-carrabiose and κcarratetraose were present. This confirms the occurrence of small amounts of κ-units in IC1 as well as the specificity of the κ-carrageenase. ι-carrageenase completely degraded IC1 to low molecular weight products, while no change was observed for KC1. In the HPLC-MS chromatogram obtained from the hydrolysis of IC1 with ι-carrageenase, three peaks could be assigned to ι-carrabiose, ι-carratetraose, and ι-carrahexaose. The mass spectra of the other later eluting peaks contained to many fragments which prevented an unambiguous assignment.