Investigation of the mass shifts caused by the coupling of ion motions in the ion trap mass spectrometer

An ion-coupling model has been proposed to predict and interpret the occurrence of mass shifts induced by the presence of ions of other m/z ratios in the ion trap mass spectrometer. The method of dynamically scanning the dipolar tickle frequency has been used to determine the mass shifts for two species of ions involved in a coupling interaction. The experimental results, together with the evidence found in published spectra, provide a fair support of the existence of ion-coupling effects which give rise to a subsequent mass shift. The ion-coupling phenomenon is expected to arise whenever more than one species of ion is trapped.