Rapid quality control analysis of C-13-enriched substrate synthesis by isotope ratio mass spectrometry

Morrison, D.J., Dodson, B., Preston, T. and Weaver, L.T. (2001) Rapid quality control analysis of C-13-enriched substrate synthesis by isotope ratio mass spectrometry. Rapid Communications in Mass Spectrometry, 15(15), pp. 1279-1282. (doi: 10.1002/rcm.341)

Abstract

There is a growing interest in the use of C-13-enriched substrates to investigate metabolic processes in humans. The non-invasive nature of C-13 breath tests makes them attractive to clinicians, particularly because they can be safely used in children. The availability of suitable C-13-enriched substrates can limit the application of this biotechnology. We have used isotope ratio mass spectrometry to assay the chemical purity and isotopic enrichment of substrates that were synthesised to study gut transit and colonic fermentation. Lactose ureide and lactose [C-13]ureide were synthesised by acid-catalysed condensation of lactose and urea or C-13 urea, respectively. Glucose ureide and glucose [C-13]ureide were synthesised by similar methods but required an additional purification step to remove urea. of crystallisation. Substrates were analysed by standard analytical techniques and combustion isotope ratio mass spectrometry for carbon and nitrogen content and C-13- enrichment. Monitoring the C/N ratio proved to be a sensitive assay of chemical purity. Analysis of the percentage composition of C and N (and hence O + H) suggested that lactose ureide crystallises as the dihydrate. It was synthesised with similar to 99% chemical purity and with the theoretical enrichment. Glucose ureide was synthesised with similar to 98% chemical purity but with lower than theoretical enrichment.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Preston, Professor Tom and Morrison, Professor Douglas
• Authors: Morrison, D.J., Dodson, B., Preston, T., and Weaver, L.T.
• Subjects: Q Science > QD Chemistry
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Rapid Communications in Mass Spectrometry
• ISSN: 0951-4198