Die ontwikkeling van 'n tandem-massaspektrometriese metode as bevestigende analise vir koolhidraat metaboliese defekte

Abstract

The study of carbohydrate structure and -metabolism has indicated the importance of these compounds in the human body. Metabolic defects in the carbohydrate metabolism, for example galactosemia and glycogen storage disease, result in serious clinical complications as well as a direct influence on the energy production in the body. The involvement of carbohydrates in multifactorial diseases has been confirmed (Burke et al, 1996:609). The increase of all these diseases contributed to the development of analytical techniques like mass spectrometry. At present, the screening procedure for carbohydrate defects, is done by thin layer chromatography. The method is fast and reasonable qualitative, but problems may occur with definite identification as well as the influence of medication on the analysis (Sewell, 1991:219). Mass spectrometry will be used complementary to thin layer chromatography in this study. The MS-analysis are based on pre-column derivatisation as well as MS-MS and LC-MS-MS detection and separation. Mono-, di-, and oligosaccharides are derivatised by PMP (1-phenyl-3-methyl-2,5- pyrazalone) and subjected to MS-MS and LC-MS-MS analysis (Rozakalis et 01, 2002). A complimentary analysis of ketose sugars is used in this study. Derivatization of fructose and fructose containing metabolites are unfavourable. Thus, an additional spectrophotometric method is implemented for the identification of fructose and related compounds (colour reaction with a thryptamine reagent) (Taylor, lWS:2 15). This three way approach is an effective screening procedure for the definite identification of carbohydrate metabolic diseases. It is indicated in this study that the use of LC-MS-MS analysis may be confirmative to the TLC-results (especially in the disorders like galactosemia). A variety of oligosaccharidoses, for example glycogen storage disease, a-mannosidosis, P-mannosidosis and fucosidosis, are successfully identified by tandem mass spectrometry. An additional spectrophotometric analysis confirms a possible fructosuria or fructose related defect. Through this approach, effective identification of carbohydrates, which may be linked to a carbohydrate metabolic disease or other carbohydrate related diseases, is made.