Natural origin of ascorbic acid: Validation by 13C NMR and IRMS

A new method for the extraction and purification of ascorbic acid from two tropical fruits (acerola and camu-camu) is presented. 13 C nuclear magnetic resonance and isotopic ratio mass spectroscopy (C-13/C-12) were used to recognize ascorbic acid coming from either natural or industrial sources. A quantitative C-13 NMR procedure was optimized to calculate isotopic relative abundances on each molecular site; data were treated by a multivariate method. Samples were also analysed by IRMS coupled with gas-chromatography/combustion and elemental analysis devices. The combined use of these techniques enabled us to validate the origins of ascorbic acid batches issuing from different sources. (C) 2008 Elsevier Ltd. All rights reserved.