Intermolecular, Site-specific and Positional Isotope Ratio Analysis

3 Intermolecular, Site-specific and Positional Isotope Ratio Analysis 

1 Mass Spectrometric Determination of Intermolecular and Intramolecular Isotopic Correlations 

The intrinsic or intermolecular standardisation (evaluation of isotopic correlations in between molecules of the same origin) demands the separation, purification and isotopic analysis of at least two components of the same source, which is, in practice of routine analysis of flavourings, normally only realisable by GC-C-IRMS or by multi-dimensional (MD)GC-C-IRMS. Instmmentation and practical performance have already been outlined in 6.2.2.2.2. 

Very informative examples for this principle are GC-C-IRMS analyses of monoterpe-nes from essential oils. Assuming that all terpenes from a given natural source are 

2 Stable Isotope Pattern Analysis by Nuclear Magnetic Resonance Measurements 

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