Claims
- 1. A method for determining the origin of substances with biological, biochemical and nutritional physiological relevance and distinguishing them from synthetic analogs using their relative positional oxygen or hydrogen isotope ratios (δ18O value and δ2H value) comprising the steps of determining—based on the fact that for organic compounds there are at least two different primary or secondary sources for these elements, each with different isotope values, and that the incorporation of these elements is accompanied by a different, but characteristic isotope effect—the positional δ18O values or δ2H values, individually in the substances to be tested, comparing them with the values expected from the biosynthesis, where a correspondence or deviation makes it possible to detect the authenticity or origin or adulteration of the substance, and detecting the authenticity or origin or adulteration of the substance.
- 2. A method as in claim 1, comprising the further step of measuring one isotope in respect of the global value, namely, the average value of all of the positional isotope values that occur in the substance to be tested, compared with the average δ18 O value expected from the correlation to the starting substances, and detecting the authenticity or origin or adulteration of the substance responsive to the comparison.
- 3. A method as in claim 1, including the step of determining in biological material the origin of the oxygen from leaf water (δ18O value +5 to −5 [%]V-SMOW, 2-8 [%]V-SMOW over that of the relevant ground water) or atmospheric O2 (δ18O value+23.5 [%]V-SMOW), the O atoms of which experience a characteristic isotope discrimination upon incorporation.
- 4. A method as in claim 1, including the steps of determining by 2H NMR the positional hydrogen (δ2H) isotope value in aromatic compounds, and comparing with the relative 2H frequency p>o>m to be expected for natural substances arising by the shikimic acid pathway or for substances substituted in p position with OH, o>m or m>o, in each case according to biosynthesis.
- 5. A method as in claim 1 including the step of testing L-tyrosine in the form of a metabolite or a component of a (macro)molecule or molecular aggregate.
- 6. A method as in claim 1 including the step of detecting the plant or animal origin of tyrosine on the basis of the different origin of oxygen and/or hydrogen and the different isotope effects as incorporated into tyrosine.
Priority Claims (2)
Number |
Date |
Country |
Kind |
100 64 457.0 |
Dec 2000 |
DE |
|
101 36 460.1 |
Jul 2001 |
DE |
|
RELATED APPLICATION
[0001] This application is a continuation of PCT International Application No. PCT/EP01/15071 filed Dec. 19, 2001, the contents of which are here incorporated by reference in their entirety.
Continuations (1)
|
Number |
Date |
Country |
Parent |
PCT/EP01/15071 |
Dec 2001 |
US |
Child |
10459414 |
Jun 2003 |
US |