Differences in molecular mobility between polystyrene foam and Brij-78 wax results in vast differences in the 1H nuclear magnetic resonance (NMR) linewidth. This allows for the convenient determination of wax content in the polystyrene foam components of inertial confinement fusion targets via solid-state NMR. Contamination levels as low as 0.1% are easily recognized and quantified, and the detection limit is calculated to be 0.02% even when only 32 transients are recorded.