prEN 18337

Scope

This document specifies a method for instrumental analysis by equilibration-isotope ratio mass spectrometry (Eq-IRMS) of liquid, aqueous food matrices to determine ¹⁸O/16O isotope ratios of the water of the product. The ¹⁸O/¹⁶O isotope ratios obtained by following this document are expressed as δ¹⁸O values relative to internationally recognised reference materials. This document does not apply to sample preparation. It is assumed that the food sample has been pre-treated as necessary and homogenised. Similarly, the interpretation of the obtained δ¹⁸O values is not covered by this document. Following this protocol will result only in isotope delta values for the sample materials. Although other instrumental techniques can be applied to determine δ¹⁸O values in liquid, aqueous food materials, these other techniques are not covered by this document.