Figure 1.

Mass spectra collected by TOF-SIMS tandem MS imaging in the positive ion mode, plotted in the range of m/z 0–920. (a) An MS¹ precursor ion spectrum acquired from a cell culture of human neuronal cells prior to the 3D analysis. (b) The MS¹ precursor ion spectrum summed over the entire 3D analysis. The m/z 430.40 precursor peak is no longer present. The orange marker highlights the distorted portion of the spectrum surrounding the monoisotopic precursor selection window. (c) The MS² product ion spectrum, with precursor selection centered at m/z 430.40, summed over the entire 3D analysis. Some of the characteristic product ions, and the precursor, are annotated with their tentative structures. (d) An MS¹ precursor ion spectrum acquired from a thin tissue section of zebrafish infected with M. marinum bacteria. The m/z 430.20 precursor peak is no longer present, and the orange marker highlights the distorted portion of the spectrum surrounding the monoisotopic precursor selection window. (e) The MS² product ion spectrum, with precursor selection centered at m/z 430.20. Some of the characteristic product ions, and the precursor, are annotated with their tentative structures