Chemical exchange of labile protons by deuterium enables selective detection of pharmaceuticals in solid formulations.

Chemically assisted swapping of labile protons by deuterons is presented for amino acids, polysaccharides, pharmaceutical compounds, and their solid formulations. Solid-state packing interactions in these compounds are elucidated by H-H isotope correlation NMR spectroscopy (iCOSY). A minuscule concentration of dopamine, 5 wt% or ∼100 μg, in a solid formulation can be detected by H NMR at 28.2 T (H, 1200 MHz) in under a minute.