CHM 2354 Lecture Notes - Lecture 20: Microchannel Plate Detector, Photomultiplier, Full Width At Half Maximum
25 May 2015
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Chm2354 lecture 20 mass spectrometry: analyzes ions need to ionize atoms so they can be detected. Ions are separated based on their mass to charge (represented as m/z) The mass seen on the periodic table is the average mass between the isotopes. Peaks of protonated and deprotonated are slightly different. Other machines may not provide sufficient mass reslulation and accuracy for obtatining the exact mass. Measurements will be slightly different due to instrument. In most species there are some isotopes are much more abundant. If our machine is high enough accuracy we can distinguish atoms with different isotopic ratios. The monoisotopic mass is the sum of the atoms in a molecule using the unbound, ground-state, rest mass of the principal (most abundant) species. Mass resolution: represents the ability to separate two adjacent masses measures the sharpness of the ms peak. Mass accuracy: indicates the accuracy of the mass information provided mass spectrometry.
