Abstract: Comparative analysis of impurities in batches of monosialotetrahexosylganglioside (GM1) powder, injections, and the intermediates for the synthesis of GM1 was performed by using high performance liquid chromatography in order to find out the possible impurities that lead to the clinical side effects. We found that there were two additional peaks in a batch of GM1 powder with retention times that were the same as that presented in the intermediates. The semi-preparative separation and collection of the two impurities in the GM1 powder and intermediates were performed, and then freeze-dried and enriched about 35 times for structure analysis. They were confirmed that the peak 1 and peak 1′ were the same compound, and so did the peak 2 and peak 2′ by electrospray ionization-quadrupole-time of flight mass spectrometric (ESI-Q-TOF MS) analysis. The structures of the compounds were deduced based on the tandem mass spectra of the main ions, proposed to be fucose-GM1. The two impurities were different on the hydrocarbon chain of the ceramide. The peak 1 has 16 groups of CH2, while the peak 2 has 18. The analysis results were consistent with the clinical results for both GM1 powder and injections. It was confirmed that the two impurities were the main cause of the side effects.

Key words: monosialotetrahexosylganglioside (GM1) , impurities, intermediate of medicines, Key words: high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS)