Combined gas chromatography-chemical ionization mass spectrometry of sphingolipids. I. Glucosyl sphingosine, ceramides and cerebrosides of the spleen in Gaucher's disease.

Trimethylsilylated glucosyl sphingosine, ceramides and glucocerebrosides were analysed by combined gas chromatography (GC)-chemical ionization (CI) mass spectrometry. Isobutane, methane and ammonia were used as reactant gasses for chemical ionization. Essentially the same fragment ions were detected in the spectra with the different reactant gases. Purified glucocerebrosides isolated from the spleen of a patient with Gaucher's disease were clearly separated into their 8 molecular species by gas chromatography. Three other minor components were detected by spectrometry, and these 11 molecular species of glucocerbrosides from the spleen of the patient with Gaucher's disease have been analysed. The ceramides obtained by periodate oxidation and then alkaline reduction of the glucocerebrosides were also separated into 11 molecular species by GC-CI mass spectrometry. Molecular weight could be determined using the major fragment ion of m/e (M+-90) in the spectra of ceramides and cerebrosides. The chemical ionization method is useful for structural analysis and determination of the molecular species of sphingoglycolipids.