A preliminary study in determining the geographical origin of wheat using isotope ratio inductively coupled plasma mass spectrometry with 13C, 15N mass spectrometry

Abstract

Commercially, wheat functionality and usage are dependent on the species and cultivars with each country tending to favour particular ones. Certain geographical origins attract a premium price so there may be a financial incentive to misdescribe grain or extend it via adulteration with cheaper varieties. A preliminary investigation was carried out to examine the utility of ICP-MS elemental isotope analysis of Cd, Pb, Se and Sr plus stable isotope gas analysis of ¹³C and ¹⁵N with multivariate statistics in identifying the country of origin of Triticum aestivum. The emphasis of this work was on differentiating USA, Canadian and European samples on the basis of their fingerprint due to underlying geogenic and anthropogenic differences rather than legislative borders. It was found that the samples in this pilot study could be geographically classified using a single analyte, δ¹³C and that the methodology shows some potential in identifying different cultivars and blends within a region using discriminant analysis. Further work, however, is required to confirm this and to determine if the methodology can be extended to identify the degree of sample adulteration.