Question

devise a general method for determining the fractional abundances of two or more isotopes from a mass spectrum. Your method must include some means of measuring the signals. You must state the the of of measuring decide that you will need to apply your method.

Answer 1

In this case, we can simply use a ruler to measure the heights of the signal. Use the same ruler all throughout to reduce deviations in the measurement.

So for example we have 3 isotopes, so we get 3 signals with heights of (for example):

isotope 1 = 62

isotope 2 = 2

isotope 3 = 8

Therefore the mass of the signals would be:

62 + 2 + 8 = 72

The fractional abundance of each isotope would be:

frac isotope 1 = 62/72 = 0.86

frac isotope 2 = 2/72 = 0.03

frac isotope 3 = 8/72 = 0.11