Variable pH kinetics: an easy determination of pH-rate profile.
The complete pH-rate profile of the hydrolysis reaction of aspirin, requiring many experiments in the past, was obtained by a single variable-parameter kinetic experiment carried out by varying the hydrogen ion concentration. The experiment was carried out spectrophotometrically, reading automatically absorbance, pH, and temperature inside the reaction vessel. The results obtained by the fast processing of the kinetic profile are identical to those obtained under the same conditions but using traditional constant-pH kinetic runs. This method provides the possibility of reducing the amount of time and chemicals usually spent in collecting kinetic data in such mechanistic studies by nearly two orders of magnitude.
Alibrandi
G
G
Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Università di Messina, Salita Sperone 31, Villaggio S. Agata, 98166 Messina, Italy. alibrandi@chem.unime.it
Coppolino
S
S
Micali
N
N
Villari
A
A
D001241:Aspirin / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D013053:Spectrophotometry
D001241:Aspirin