Definition of terms

List of term

• Base peak (BP) (from [1]): Peak in a mass spectrum that has the greatest intensity.
• Base peak profile (BPP) (adapted from [1]): Profile (Chromatogram, electropherogram or other) obtained by plotting the intensity of the base peak ions in each of a series of mass spectra recorded as a function of retention or migration time.
• Base peak spectrum (BPS): spectrum obtained by recording the highest intensity at each m/z during a separation. Note: Only relevant for profile spectrum
• Centroid mode or centroid scan or centroid spectrum (from [1]): Procedure of recording mass spectra (profile mode) in which an automated computer-based system detects peaks, calculates the centroid based on the average m/z value weighted by the intensity, and assigns m/z values based on a calibration file. Only the centroid m/z value and the peak magnitude are stored.
• Extracted ion profile (EIP) (from [1]) Any plot of signal intensity observed at a chosen m/z value or set of values in a series of mass spectra (centroid of profile mode) recorded as a function of time, including extracted ion chromatogram, extracted ion electropherogram, or from flow injection analysis or any other time-dependent sampling.
• Frequency ion spectrum (FIS): number of non-nulls values at each m/z during a separation. Note: Only relevant for profile spectrum
• Mass spectrum (from [1]): Plot of the relative abundances of ions forming a beam or other collection as a function of their m/z values. Note: The term is a misnomer because it is m/z rather than mass that is the independent variable in a mass spectrum
• Profile: Chromatogram, electropherogram, or other two-dimensional traces obtained by a detector of a separation techniques
• Profile mode or profile scan or profile spectrum (from [1]): Method for acquiring a mass spectrum where each peak is displayed as a curve, with the data points defining the curve corresponding to the signal intensities at each particular m/z value.
• Pure ion profile (PIP)
• Total ion profile (TIP) (adapted from [1]): Profile (Chromatogram, electropherogram or other) obtained by summing the intensity of all ions in each of a series of mass spectra recorded as a function of retention or migration time.
• Total ion spectrum (TIS): summation of all MS spectra obtained during a separation Note: Only relevant for profile spectrum
• X-HRMS: a separation technique hyphenated with high resolution mass spectrometry

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[1]: K. K. Murray, R. K. Boyd, M. N. Eberlin, G. J. Langley, L. Li and Y. Naito, "Definitions of Terms Relating to Mass Spectrometry" (IUPAC Recommendations 2013) Pure Appl. Chem. 2013, 85, 1515-1609.