Abstract
We describe the results of FAB/MS analysis of urine sediments from a patient, 12-year-old boy, who had peripheral neuralgia, impediment in perspiration and angiokeratoma of his skin. Glycosphingolipids in urine sediments from the patient were extracted with chloro-form-methanol by the method of Folch's partition. Ceramide trihexoside (CTH) fraction in the glycosphingolipids was purified by silicic acid column chromatography and thin layer chromatography. The purified CTH fraction was analyzed by positive FAB/Mass spectrometry. The condition of FAB/MS analysis was as follows; first beam was Xe gas, emission current and acceleration voltage were 20mA, 2KV, respectively. JEOL JMS-DX 300 mass spectrometer was used in this study.
Glycerine, triethanolamine and triethanolamine-added NaOH were tested as matrices. As glycerine matrix was used, molecular ions, [CTH+H]+, weakly detected at m/z 1136 (composed fatty acid C24:0), 1134 (C24:1), 1108 (C22:0) and fragment ions were shown as the results from sugar chain cleavage, dehydration at m/z 1118, 1116 and 632. As triethanol-amine-added NaOH matrix was used, [CTH+Na]+ were strongly detected at 1158, 1156, 1130, respectively and S/N ratio was significantly made improvement than glycerine matrix. By the results of FAB/MS analysis of glycosphingolipids, chemical diagnosis of Fabry's disease could be made. This method could be applied to the detection of abnormal metabolic substances which are caused by hemi or heterozygotes with many inherited lysosomal enzyme deficiencies. FAB/MS method will be widely used to analyze many valuable substances in the section of clinical chemistry.
