Isotopic analysis methods belong to the most modern and up-and-coming analytical methods. They are used for determination of origin and composition of products. The equipment in CTL is as follows: nuclear magnetic resonance spectrometer (NMR) and isotope ratio mass spectrometer (IRMS). Laboratory unit of isotopic analyses is equipped with large number of accessories for the sample preparation and for control of process e.g. elementary analyser, gas chromatograph with combustion unit, equilibration unit, microwaves decomposition unit, automatic distillation and rectification system, electronic density meter, automatic titrator etc.
Isotopic methods (SNIF-NMR, IRMS, ICP-MS) determine ratio of stable isotopes of basic elements of organic mater. This ratio is characteristic for biological, geographical, technological or another origin of some products. SNIF-NMR method determines D/H ratio in various sites of organic molecules e.g. ethanol. IRMS method determines D/H, 13C/12C, 18O/16O ratios in products and in their components. ICP-MS method determines isotope ratio of nearly any element. After determination of isotope ratios followed by their comparison with standards one is able to indicate for example:
- Botanical origin of ethanol in alcoholic beverages.
- Technological origin of ethanol to distinguish between natural and synthetic one in distillates.
- Botanical origin of sugars and amount of added sucrose in fruit juices.
- Amount of added water in wines.
- Origin of cereals, natural fats, natural textile fibbers.
Isotopic methods are indispensable in determination of origin of the goods produced from natural sources. Especially in the field of alcohol and alcoholic beverages they have the primary importance for disclosure backdoor moving of the goods and for detection of adulteration of the goods. The possibilities of isotopic methods and quality of the interpretation of measured results depend on the range of the databases of isotopic parameters of the products and their components. In addition to commercial databases the isotopic section creates their own databases for example: Czech and Moravian wines, fruit juices, and bee honeys.
To be sure about quality of measured results of these isotopic methods the section participates in the inter-laboratory proficiency testing and some of these methods are accredited. At present this section belongs to the very well equipped isotopic laboratories all over the world and proficiently co-operates with other well recognized international institutions.
