CHROMATOGRAPHY, Vol. 27 (2006), No. 2, pp. 73-79
Technical Review
Development of a unique software tool to predict empirical formulae utilizing accurate mass MSn measurements
Yusuke Inohana＊, Shinichi Yamaguchi, Norio Mukai and Ichiro Hirano
Analytical Applications Department, Analytical & Measuring Instruments Division, Shimadzu Corporation
1, Nishinokyo−kuwabaracho, Nakagyo−ku, Kyoto 604−8511, Japan
Abstract:
Since a hybrid quadrupole ion trap TOF system generates MS and MSn spectra, the prediction tool set can use the fragment ion data to reduce
the list of potential candidates and remove invalid formulae. Although the main variables affecting the returned scores for potential candidates
are mass accuracy and isotopic distribution for the MS spectra, results presented will also highlight the importance of fragment ion data. The
fragment ion data helps in filtering candidates by allowing for the ability to remove invalid formulae thus helping to identify the correct empirical
formula with a higher degree of confidence without the need for using sub−ppm mass accuracy data. This paper will also show the importance
of advanced modeling tools for fitting experimental and theoretical mass accuracy and isotope distribution data applied to empirical
formula prediction using a diverse chemical library as a test system.
Keywords:
quadrupole ion trap, TOF, MSn, mass accuracy, isotopic distribution, empirical formula
