Determination of pH using water protons and chemical exchange dependent saturation transfer (CEST).
Solution pH was measured using water proton NMR via chemical exchange dependent saturation transfer (CEST) with selected chemical exchange sites. Several useful pH-sensitive proton chemical exchange agents were found: 5,6-dihydrouracil, 5-hydroxytryptophan, and a combination of 5-hydroxytryptophan and 2-imidazolidinethione. A ratiometric approach was developed that permitted pH determinations that were independent of water T(1) or exchange site concentration.
Ward
K M
KM
Laboratory of Cardiac Energetics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
Balaban
R S
RS
D003287:Contrast Media / Q000737:chemistry / Q000378:metabolism; D005682:Gadolinium / Q000737:chemistry / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D011522:Protons; D014867:Water / Q000737:chemistry
D003287:Contrast Media; D011522:Protons; D014867:Water; D005682:Gadolinium