In this technique, a substance is first volatilized and then ionized with the help of a high energy beam of electrons. The gaseous positive ions, thus formed, are separated based on their masses to charge ratio (m/e) and then recorded in the forms of peaks. Mass Spectrum is the plot of data in such a way that (m/e) is plotted as abscissa (x-axis) and the relative number of ions as ordinate (y-axis).
“The average atomic mass of an element is the sum of the masses of its isotopes, each multiplied by its natural abundance. Atomic Masses depends upon the number of possible isotopes and their natural abundance.”