Patent ID: 8164054
Filing Date: 2012-04-24
Classification: H01J

Abstract:
1. A mass analysis method using a multi-turn time-of-flight ion optical system in which ions originating from a sample is made to fly repeatedly along a loop orbit and then, at a predetermined point in time or later than that, divert from the loop orbit to be detected by a detector, which is characterized by comprising: a) a no-passing mode execution step for obtaining a time-of-flight spectrum by performing a mass analysis of a target sample in a no-passing mode in which the ion is either prevented from completing one turn along the loop orbit or allowed to fly through the loop orbit a number of times within a range where any ion is assuredly prevented from lapping or passing another ion; b) a peak information collection step for collecting information relating to a peak appearing on the time-of-flight spectrum obtained by an operation of the no-passing mode; and c) a timing determination step for predicting, based on the collected information relating to the peak, a number of turns and a time of flight corresponding to the peak to be observed when a mass analysis of the target sample is performed in a loop-turn mode in which the ion is made to fly through the loop orbit, and for determining a timing for beginning a diversion of the ion from the loop orbit so that at least a peak corresponding to an ion of interest can be separately identified on a time-of-flight spectrum based on an prediction.