Rapid, Quantitative Nuclear Magnetic Resonance Test for Oxygen-17 Enrichment in Water

Anal Chem. 2022 Apr 19;94(15):5741-5743. doi: 10.1021/acs.analchem.2c00081. Epub 2022 Apr 4.

Abstract

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 13C═16O and 13C═17O 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.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Magnetic Resonance Spectroscopy
  • Oxygen Isotopes / chemistry
  • Prothrombin Time
  • Stanford-Binet Test
  • Water* / chemistry

Substances

  • Oxygen Isotopes
  • Oxygen-17
  • Water