Sialic Acids and Methylation Analysis

The foregoing demonstrates that if exact mass measurements are carried out, each fragment as such can provide essential structural information. However, it should be emphasized that, if working under low-resolution conditions only, the whole series of selected fragment ions form a self-consisted system, in which the interpretation of the fragment ions should support each other. It is obvious that to arrive at an unambiguous conclusion about the substitution pattern, the whole mass spectrum should also be considered. 

Finally, it has to be mentioned that methylation analysis data have also been 

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