Real-Time Reaction Monitoring by Continuous-Introduction Ion-Spray Tandem Mass Spectrometry

Article abstract of DOI:10.1021/ja00195a012

A temperature-controlled reaction vessel was closely coupled to the ion-spray LC/MS interface on an atmospheric pressure ionization, triple quadrupole mass spectrometer and used to study mechanistic and kinetic aspects of reactions taking place in solution.Free access to the reaction vessel and temperature control as well as minimal sample consumption make continuous-introduction ion-spray mass spectrometry a useful approach for real-time measurement of reactions.The reaction medium, reactants, and products were transferred to the ion source of the mass spectrometer from the reaction vessel in less than 1 s.A variety of model reactions have been investigated to demonstrate the feasibility and potential for continuous-introduction ion-spray mass spectrometry for real-time reaction monitoring.The half-life for the solvolysis of methandrostenolone sulfate in aqueous medium and the Michaelis-Menten constant of the enzymatic hydrolysis of O-nitrophenyl β-D-galactopyranoside by lactase were determined.The enzymatic hydrolysis of dynorphin 1-8 by α-chymotrypsin and leucine aminopeptidase and the reduction of the disulfide bridge in oxytocin with β-mercaptoethanol were obtained on-line to emphasize the technique's capability for peptide sequencing and structural elucidation.