Relative intensity chart
Of course, compounds of chlorine and bromine have very large isotope abundances.Ī more elegant and complete isotope pattern calculator has been created by Junhau Yan. The numbers displayed in the M+1 and M+2 boxes are relative to M being set at 100%. Simply enter an appropriate subscript number to the right of each symbol, leaving those elements not present blank, and press the " Calculate" button. The calculator on the left may be used to calculate the isotope contributions to ion abundances 1 and 2 amu greater than the molecular ion (M). For compounds of chlorine and bromine, increments of 1.997 and 1.998 respectively must be added for each halogen to arrive at the higher mass isotope values. Only the mass of the most abundant isotope, relative to C (12.0000), is used for these calculations. The mass calculator on the right may be used to calculate the exact mass of a molecule based on its elemental composition. This table is adapted from Introduction to Mass Spectrometry, by J.T. The factor is multiplied by the number of atoms (n) of the designated element to calculate the intensity contribution from higher mass isotopes. * X represents the relative intensity of the lowest mass ionin an isotopic ion cluster. Masses Exact Masses & Isotope Abundance Ratios Element