To effectively compare whether gas-phase acetylation truly is more regioselective than the alternative liquid-phase methods, an analytical workflow was set up whereby the FD-CNCs were acetylated under different conditions: in gas or liquid Ac2O, catalysed or uncatalyzed, at two temperatures (RT & 80 °C) with 3 kinetic time points (1, 2 & 6 d) (Figure ). The bulk DS of acetylation was determined for each by 1 H NMR (peak fitting, SI-Section S2.4).