title: DFTMP, an NMR reagent for assessing the near-neutral pH of biological samples.
abstract: A new NMR chemical shift standard and pH indicator, difluorotrimethylsilanylphosphonic acid (DFTMP), is described, and the utility of this reagent is demonstrated for in situ determination of pH in complex biofluids. The pH dependence of this reagent allows accurate in situ determination of aqueous solution pH to within an RMSE of 0.02 pH units over a pH range of 5 to 8. Advantages of this reagent over previously described pH-sensitive components include (1) lack of metal binding affinity, (2) minimal disturbance of endogenous spectral regions, and (3) the potential to function as a multinuclear pH indicator and chemical shift reference point for 19F, 1H, and 31P nuclei. This reagent will be generally useful for NMR experiments on biological systems where the pH needs to be accurately measured at the moment of data acquisition.
authors.affiliation: Pfizer Global Research and Development, 2800 Plymouth Road, Ann Arbor, Michigan 48105, USA. michael.reily@pfizer.com
authors.forename: Michael D
authors.initials: MD
authors.lastname: Reily
authors.forename: Lora C
authors.initials: LC
authors.lastname: Robosky
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Manning
authors.forename: Andrew
authors.initials: A
authors.lastname: Butler
authors.forename: John David
authors.initials: JD
authors.lastname: Baker
authors.forename: R Thomas
authors.initials: RT
authors.lastname: Winters
mesh_terms: D000818:Animals; D002118:Calcium / Q000737:chemistry / Q000652:urine; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents / Q000138:chemical synthesis / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry / Q000652:urine; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D051381:Rats; D014297:Trimethylsilyl Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D014556:Urine / Q000737:chemistry*
chemical_list: C522995:1,1-difluoro-1-trimethylsilanyl methylphosphonic acid; D007202:Indicators and Reagents; D014297:Trimethylsilyl Compounds; D008274:Magnesium; D002118:Calcium