High resolution 1H n.m.r. studies of vertebrate blood and plasma

Spin echo Fourier transform proton n.m.r. spectra of whole blood contain resonances from both erythrocytes and plasma. A large number of well-resolved signals from mobile protons of low-molecular-weight metabolites in plasma and serum have been identified. Spectra from the plasmas of eight animal species and commercial, quality control sera are compared. CaEDTA2- and MgEDTA2- resonances can be used for the simultaneous determination of EDTA-chelatable calcium and magnesium concentrations in intact plasma and other biological fluids. Cholesterol is too immobile to contribute to the spectra of intact plasma, but is readily estimated by n.m.r. in both its free and esterified forms after extraction into methanol.