The sulfate contents of the carrageenans are shown in Table . Generally, comparable sulfate contents were obtained by using the two methods, but some differences were observed between the carrageenan types. For the κ-carrageenan and unspecified carrageenan samples, the sulfate contents calculated from ICP-OES were slightly lower than from the IC analysis, whereas no trend was observed for ι-carrageenans. In contrast, the sulfate contents determined by ICP-OES were in some cases higher than the ones determined by IC in case of the λ-carrageenan samples. Nevertheless, both methods are suitable to obtain information on the degree of sulfation. As expected, the ι-carrageenan samples contained higher sulfate contents than the κ-carrageenan samples which is caused by the presence of a second sulfate group at the DA unit. However, IC3 and IC4 showed a clearly lower sulfation degree. This can be explained by the presence of κ-units (IC3) as well as the presence of glucose and sucrose (IC3 and IC4). Furthermore, the presence of sucrose also explains the sulfate content of C2 which was lower than expected for a carrageenan with 41 % ι-units. Although the obtained values for κ-and ι-carrageenans were slightly lower than in the literature , the results confirm the carrageenan type determined by NMR spectroscopy. The sulfate contents obtained for the LC samples were all below the theoretical value for λcarrageenan (calculated from the mass fraction of sulfate in a carrageenan with strictly repeating G2S and D2S,6S units). This is in good agreement with the absence of λ-units in the NMR spectra. For LC2 and LC6, the sulfate contents were in good agreement with the contents which were expected based on the NMR spectroscopically determined carrageenan composition. The samples LC1, LC3, LC4, LC5, and C1 showed higher degrees of sulfation which is in good agreement with the occurrence of ν-units (trisulfated repeating unit) in these carrageenans.