Experimental methods have been developed which permit operation of the standard ICR cell in a trapped ion mode. Appropriate configurations of applied electrostatic fields permit trapping of ions in the source region of the ICR cell. Detection is effected after a suitable delay by drifting the ions from the source through the analyzer region where their power absorption is monitored with the usual marginal oscillator-detector. The minor modifications required do not inhibit normal operation of the cell, thus allowing for the full range of conventional ICR experiments with the additional capability of examining variation of ion abundance with time. The latter mode of operation greatly simplifies elucidation of reaction kinetics. The ion molecule reactions of methyl chloride have been investigated using this new technique. Accepted values of reaction rate constants are reproduced, demonstrating the accuracy of the method
