| 摘要 |
The present invention aims at creating an accurate mass spectrum with a high resolving power based on a plurality of multi-turn time-of-flight (TOF) spectra, while reducing the amount of computation to assure the real-time processing. First, a plurality of TOF spectra each obtained for a different timing when ions are ejected from the loop orbit are measured (S2 and S3). At this point, the concept of the coincidence detection method is utilized to determine what mass-to-charge ratio a peak appearing on the TOF spectra originates from. From the information on the peak of interest in one TOF spectrum and other data, the time range in which a corresponding peak appears on other TOF spectra is set, and the existence or nonexistence of the peak in that range is determined (S5). In the case where the corresponding peak is found on most of the other TOF spectra, the m/z is deduced from the peak on the TOF spectrum with the highest resolving power and a mass spectrum is created (S6 and S7). At the same time, from the density of the peaks around the peak of interest, the reliability of the deduction is computed. For a peak with a low reliability, the ion ejection time is optimized and the TOF spectrum is measured again (S8).
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