Characterization of GM1 ganglioside by direct inlet chemical ionization mass spectrometry.

Intact permethylated and permethylated-reduced (LiAlH4) derivatives of GM1 ganglioside were analyzed by direct inlet ammonia chemical ionization (CI) mass spectrometry. In addition, the trimethylsilylated derivative of the permethylated-reduced sample of this ganglioside was similarly analyzed. CI mass spectrometry proves to be a highly satisfactory method for structural studies of GM1 ganglioside because of the simple fragmentation pattern and the presence of prominent molecular ions and fragment ions in the high mass region. Complete information on the carbohydrate sequence and lipophilic composition can be easily obtained.