Fig. 2.

(a) Representative ¹³C NMR spectrum of HP ¹³C-GLC after hydrolysis. The ¹³C-GLC peak is referenced to 158.6 ppm. (b) Excitation pulses and simulated frequency profiles used for co-localizing HCO₃^– and CO₂ at 14 T. The degree of excitation of each resonance (bicarbonate : CO₂) was in the ratio of 1 : 1 (left) or 1 : 9 (right) (c) pH phantom results at 14 T: (left) T₂-weighted ¹H image, with electrode-measured pH values in white; (right) HP ¹³C spectra and calculated pH values for each color-coded voxel in left image. Spectra were obtained using an excitation pulse from (b), as indicated above each column.