Abstract: A combination of collision-induced dissociation (CID) and ion-molecule (IM) reaction was used to study the reequilibrium procedure which took place in a quadrupole ion trap mass spectrometer. The re-equilibrium in the gas phase was found to proceed through ligand loss, gain or exchange reaction with the participation of solvent ligands methanol and water. Quantitative CID measurements depending on activation time were carried out. The comparison among the kinetic behaviors of the cycled metal complexes reveals that the chemical re-equilibrium occurred in the gas-phase system is due to the thermodynamic stability of original metal complex.