The IPQ is defined as the sum of the absolute differences between observed and theoretical fractions per isotopic peak. However, it is often interpreted/reported as the fraction/percentage deviation (in other words, the sum of the percentage difference between the observed and the theoretical fraction). It should be discussed whether the explanation or the calculation of the IPQ should be adjusted.
The IPQ is defined as the sum of the absolute differences between observed and theoretical fractions per isotopic peak. However, it is often interpreted/reported as the fraction/percentage deviation (in other words, the sum of the percentage difference between the observed and the theoretical fraction). It should be discussed whether the explanation or the calculation of the IPQ should be adjusted.