Position-Specific Isotope Analysis by Isotopic NMR Spectrometry: New Insights on Environmental Pollution Studies

The common practice of measuring the change in isotope ratio for the whole molecule using isotope ratio measurement by mass spectrometry leads to the loss of significant information of potential interest, since it is the position-specific fractionation which most closely reflects the effect of physicochemical processes. We have shown for MTBE, a common ground water contaminant, that isotopic quantitative 13C NMR spectrometry can be effectively applied to obtain this position-specific data. It is found that different characteristic position-specific isotope fractionation patterns are introducedby different types of evaporative process or by oxidative degradation.