https://doi.org/10.1351/goldbook.M03752
The abbreviation \(\frac{m}{z}\) is used to denote the dimensionless quantity formed by dividing the @M03726@ of an ion by its @C00993@. It has long been called the mass-to-charge ratio although \(m\) is not the ionic mass nor is \(z\) a multiple or the elementary (electronic) charge, \(e\). The abbreviation \(\frac{m}{e}\) is, therefore, not recommended. Thus, for example, for the ion (C7H72+) , \(\frac{m}{z}\) equals 45.5.