CEN/TC 460/WG 6 - Stable Isotope Analysis

This document specifies a method for the determination of the ratio of stable isotopes of carbon (13C/12C) of sugars contained in honey by using liquid chromatography coupled to an isotope ratio mass spectrometer (LC-IRMS) for compound separation and subsequent determination of the 13C/12C ratio of mono-, di-, and trisaccharides. These ratios can be used to assess honey authenticity by comparing them to guidance values of genuine honey, which have been previously agreed by subject matter experts, as the 13C/12C ratios of sugars of genuine honey and sugars contained in adulterants (syrups made from starch-rich plants or from sugar cane or sugar beet) differ to a certain extent.
The compliance assessment process is not part of this document.

This document specifies an isotopic method to control the authenticity of vinegar and food containing vinegar as an ingredient (for example Aceto Balsamico di Modena), with a density below 1,28 g/cm3. This method is applicable on acetic acid of vinegar (from wine, cider, agricultural alcohol, etc.) in order to characterize the botanical origin of acetic acid and to detect adulterations of vinegar using synthetic acetic acid or acetic acid from a non-allowed origin (together with the method described in EN 16466 2).
The isotopic analysis of the extracted acetic acid by 2H-NMR is based on a similar method already normalized for wine analysis[10].

This document covers instrumental analysis by elemental analyser-isotope ratio mass spectrometry (EA-IRMS) of food materials to determine C and/or N isotope ratios.
The isotope ratios obtained by following this document are expressed as δ13C and/or δ15N values relative to international measurement standards.
Sample preparation is not included within this document. It is assumed that the food sample has been pre-treated as necessary and homogenized.
Similarly, the interpretation of the obtained isotope delta values is not covered by this document. Following this protocol will result only in isotope delta values for the sample materials.
Solid and/or liquid sample materials can be analysed following this document.
Although other instrumental techniques can be applied to determine δ13C and/or δ15N values in food materials, these other techniques are not covered by this document.

This European Standard specifies an isotopic method to control the authenticity of vinegar. This method is applicable on acetic acid of vinegar (from wine, cider, agricultural alcohol, etc.) in order to characterise the botanical origin of acetic acid and to detect adulterations of vinegar using synthetic acetic acid or acetic acid from a non-allowed origin (together with the method described in FprEN 16466-2).
The isotopic analysis of the extracted acetic acid by 2H-NMR is based on a similar method already normalised for wine analysis [2].
The application to complex matrices made with vinegar as an ingredient, such as balsamic vinegar, is out of the scope of the inter-laboratory validation performed.