In this brief contribution we demonstrate that 1H and 2H NMR spectroscopy can be an effective method of investigating adsorption from liquids at the solid-liquid interface. The method is illustrated here with the adsorption of a simple alkane adsorbed on graphite, in particular the system n-dodecane and graphite at coverages of 1 and 5 monolayers. Static single-pulse proton nuclear magnetic resonance and static quadrupolar echo deuterium nuclear magnetic resonance spectra were recorded for both coverages. The experimental NMR results presented here show features clearly consistent with earlier calorimetric and neutron scattering work and demonstrate the formation of solid adsorbed layers that coexist with the bulk adsorbate with both isotopes. This ability to probe both deuterated and protonated materials simultaneously illustrates that this experimental approach can be readily extended to investigate the adsorption behaviour of multicomponent mixtures.