日本質量分析学会 第67回質量分析総合討論会

Abstract

Poster Presentations

Day 3, May 17(Fri.)  Room P (Multi-purpose Hall)

Improved Quantitative Dynamic Range of Time-of-Flight Mass Spectrometry by Simultaneously Waveform Averaging and Ion-Counting Data Acquisition

(1Osaka Univ., 2Osaka Univ.)
oYosuke Kawai1,2, Toshinobu Hondo2, Kentaro Terada1,2, Michisato Toyoda2

The most common data acquisition method in a time-of-flight (TOF) mass spectrometry is an "averaging mode" that sums ion current signals obtained from a detector for each flight cycle. While it is possible to process many ions arrived at the detector at the same TOF in one flight cycle, low abundance ions are difficult to measure because the spectral quality easily affected by noise signals from the detection system. An “ion-counting mode” is suitable for the measurement of such low concentration ions, but counting loss occurs when two or more ions arrive at the detector within the dead time of the acquisition system. To compensate for these disadvantages, we have developed a new data acquisition method that combines two modes to measure target ions with a high concentration difference, i.e., averaging mode and ion-counting mode are used simultaneously for high abundant and trace ions, respectively. The result of the argon isotope analysis shows that this method provides a more accurate determination of the isotope ratio compared to averaging mode alone at one-twentieth of the analysis time required by ion-counting mode alone.