Mass Spectra interpretation
After reaching the detector, the data on mass over charge ratio of the different fragments are turned into a spectrum. Remember, that this happens only if the fragment was a charged cation, otherwise it won’t be visible. On the X axis we find the m/z value of the fragments, while on the Y axis we find their relative abundance. Each line in the spectrum represents a different fragment produced when the molecule breaks. The highest peak on the graph is defined as base peak and given the relative value of 100, as it represents the most common ion to be formed. The molecular ion peak is the peak at highest m/z value and it indicates the ion of the sample molecule; note that it can be accompanied by the M+1 peak, which represents a possible isotope in the molecule.