Strategy for specific isotope ratio determination by quantitative NMR on symmetrical molecules: application to glycerol

The strategy for the measurement of the site-specific isotope ratios by NMR within a symmetrical molecule is illustrated by the determination of the site-specific C-13 content in glycerol on the basis of (i) a selective derivatisation of glycerol, carried out by a lipase (Candida antarctica) to overcome the symmetry of the molecule, (ii) purification of the (R)-monobenzoate glycerol with a high enantiomeric excess and (iii) use of this derivative for quantitative C-13 NMR spectroscopy for the determination of C-13 isotopomer concentrations. (c) 2006 Elsevier Ltd. All rights reserved.