Marking manufactured product comprises adding or partially substituting isotopic derivative of one component and verifying product identity by mass spectrometry of sample of that component

A component X, which is a constituent of the manufactured product, is selected and a predetermined quantity of an isotopic derivative of component X is added to it or replaces part of the product. The product identity is verified by analysis using a mass spectrometer of a sample of the component X and its isotopic derivatives. The isotopic derivative is a derivative in which one or more hydrogen atoms are substituted by one or more deuterium atoms. Two or more derivatives are added to the manufactured product, for example using two or more isotopic derivatives X1, X2 etc. of the same component X. Each derivative represents between 10 ppm and 10% of the natural component X. Component X is selected as a component of the manufactured product forming less than 20 wt.% of the product. The manufactured product is a mixture of components such as a colorant, a flavouring or a perfume. Predetermined quantities of four or more isotopic derivatives are added to the product. An independent claim is made for verifying the identity of a manufactured product in which the original example has been marked as above. The component X and its derivatives are separated partially or totally before analysis using a mass spectrometer. Un procédé de marquage d'un produit manufacturé, caractérisé en ce que l'on choisit un composé X qui est un constituant dudit produit manufacturé, et en ce que l'on ajoute à la composition dudit produit manufacturé une quantité déterminée d'un dérivé isotopique dudit composé X ou remplace une partie dudit produit manufacturé par une quantité déterminée d'un dérivé isotopique dudit composé X, et procédé de vérification de l'identité d'un produit manufacturé dans lequel l'exemplaire original a préalablement été marqué par mise en oeuvre du procédé de marquage ci-dessus et dans lequel on procède à une analyse par spectrométrie de masse d'un échantillon du composé X.