One dimensional ¹³C NMR spectra of galactose (top) and glucose (bottom) in a solution of 1 : 1 H₂O : D₂O. The spectra clearly show the effect of isotopic deuterium substitution, which in many cases produces two chemical shifts, one for C–OH (less shielded) and the other for C–OD (more shielded). Using this spectrum, the ¹³C spectrum and two additional spectra (one obtained in 100% D₂O, the other obtained in 100% H₂O) allows for the use of line shape analysis to deduce OH/OD exchange rate constants.