RESUMO
Nuclear magnetic resonance (NMR) studies involving 17O are increasingly important in molecular biology, material science, and other disciplines. A large number of these studies employ H217O as a source of 17O, and this reliance can be limiting because the high cost of H217O. To overcome this constraint, a recent study proposed a distillation scheme capable of producing significant quantities of H217O at a low cost. Although this method is reported to be effective, the reactions proposed to quantify percent of 17O enrichment are either time intensive or have a risk of errors due to the isotope effect. Here, an alternative reaction scheme is described to measure 17O water that ultimately creates methyl benzoate as the sole 17O-containing product. The proposed reaction is completed in a matter of minutes at room temperature, produces only one 17O product, and requires no clean-up step. The large isotope shift observed in solution NMR between the 13Câ16O and 13Câ17O resonances allows for integration of the individual peaks. This 13C NMR analysis is found to be highly accurate over a wide enrichment range and is accessible to most NMR spectroscopists.
