Evaluation of Differences in MS/MS Spectra from Two Differentgeneration Q-TOF Instruments: Implications for Metabolomic Database Use

Abstract

Generating reproducible fragmentation patterns is a problem in electrospray ionization mass spectrometry. Two generations of quadrupole time-of-flight(Q-TOF) instruments were selected to evaluate the reproducibility of tandem mass spectrometry(MS/MS) spectra:an old-and a new-generation instrument. Ninety-four MS/MS and MS/MS/MS spectra with information-rich product ions were obtained in positive-or negative-ion mode with two different-generation Q-TOF instruments, BioTOF-Q and micrO-TOF-Q. Two principles were selected to optimize the collision energy. On the one hand, maximal structural information is obtained when the collision energy is increased; on the other hand, when most product ions show relative abundance of more than 10%, the lowest collision energy should be selected. The Paired-Samples T Test method was used to analysis these paired-spectra. We found that most product ions were the same and the profiles of the product ions were similar with both Q-TOF instruments. Interestingly, at the low signal to-noise ratio (S/N) of the precursor ion (ion intensity low to 180 counts), the profile of the MS/MS spectrum is very similar to that at a high S/N. Furthermore, when spectra were generated with micrOTOF-Q even before and after a four-year interval, the profiles and product ions were virtually identical. In summary, databases built with different-generation Q-TOF instruments may be universally applicable.

Recent (2000–2015) developments in the analysis of minor unknown natural products based on characteristic fragment information using LC–MS

“…a). To evaluate the differences in the MS/MS spectra of two different‐generation Q‐TOF instruments, Wu et al used another QTOF instrument to analyze known epipolythiodioxopiperazines and obtained the same MS/MS spectra (Guo et al, ). This indicates that MS/MS databases built with different‐generation Q‐TOF instruments may be universally applicable.…”