The analytical origin testing is based on natural differences found in the isotope values in water, plants and animals at different geographical locations. These geographical differences do not correspond automatically to country or state/province borders determined by men, but rather orient themselves to climatic and ground specific factors.
For example, beef stemming from the region of South Germany can clearly be distinguished from north German beef.
Another example is that vegetables out of the Spanish region Andalusia shows very distinct isotope values.
Different vineyards can often be distinguished very well through quite specific isotope values in the the wine.
Even within the border of Luxembourg, different regional isotope values could be assessed for wheat.
In a large project, the region Wendland-Elbetal in the state Lower Saxony was examined with respect to characteristic Isotope values. A detailed project description and its results are found on the web page www.farm-id.de
The base of a reliable statement again is formed by authentic reference material which necessary quantity and diversity depends on the particular test objectives.
According to the objectives and and the size of the defined region, it can be advisable to find out beforehand whether a defined region can be characterized by typical isotope values.