The Spinsolve high-resolution bench-top NMR spectrometer has been used to monitor the reaction kinetics of the hydrolysis of acetic anhydride, detecting concentrations of less than 0.5%.
The hydrolysis of acetic anhydride to acetic acid was carried out in water, described in the latest application note ‘Benchtop NMR Reaction Monitoring for Kinetic Profiling’. The reaction was pumped from the reaction vessel through Teflon tubing into the Dewar in the bore of the magnet. Using continuous flow, spectra were acquired every 15 seconds using the Reaction Monitoring feature in the Spinsolve software. The rate constant of the reaction was determined assuming a pseudo-first order reaction due to the large excess of water in the reaction. The reaction was repeated at various temperatures and, using the Arrhenius Equation, the activation energy of the reaction was determined.
The ability to measure in continuous flow mode for more than 30 minutes is due to the superior stability and resolution of the Spinsolve.