Zhanping Li oral presentation (FN3-Fri1-2-5)
A discussion on mass resolution
A comparison of mass resolution between TOF and magnetic SIMS considering real peak shapes
1 Tsinghua University, Haidian, 100084 Beijing, China
2 Institute of Semiconductors, CAS, Haidian, 100083 Beijing, China
3 Institute of Geology, CAGS, Xicheng, 100037 Beijing, Chile
Mass resolution is a very important parameter for mass spectrometry. As such,it is necessary to compare the mass resolution between the newly developed TOF-SIMS with the conventionally used high-performance magnetic SIMS towards geological applications. The definitions of mass resolution for the above two types of instruments are quite different. Whether it is possible and how to do the comparison is a challenge that has been proposed for discussion at the 2012 ISO/TC 201 meeting in Tampa, US. The related resolution is required to investigate the existing standards on mass resolution and report at the next ISO/TC 201/SC 6 meeting. This constitute the background of this discussion.
Due to historical reasons, quite different definitions for mass resolution and testing methods have been developed and used, including the established national and international standards, such as AVS, ASTM, ISO, and IUPAC etc.[1-2]
However, nearly all of the existed definitions of mass resolution nowadays still used just restrict the peaks to be at a specific position in spite of the quite different peak shapes, which is impossible to be used to compare instrument performance. Therefore, it is very important to show the real peak shape to give a correct definition of mass resolution. Current evidence suggests that it is one of the most important and fundamental problems for mass spectrometry that should attract enough attentions.
A new definition for mass resolution as well as a method to calculate it by considering the peak shape is suggested to compare the mass resolution between TOF and magnetic SIMS, which is confirmed by experimental results as well. The investigation, discussion and experimental studies during the past four years, including cooperation with ISO/TC 201/SC 6 and SC 1, are summarized and discussed in this paper.