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Table 1 Sequential correction of 13C natural abundance effects in a four-carbon example

From: Correcting for the effects of natural abundance in stable isotope resolved metabolomics experiments involving ultra-high resolution mass spectrometry

IM+i=bValue = (cIM+i;NA- ΣIM+x*BC(x, i))/(1 - BCsum(i))

IM+0 = 1.00 = (0.956)/(1.00 - 4.36E-2)

IM+1 = 1.00 = (1.01 - 1.00 * 4.29E-2)/(1.00 - 3.29E-2)

IM+2 = 0.00 = (3.33E-2 - 1.00 * 7.22E-4 - 1.00 * 3.25E-2)/(1.00 - 2.21E-2)

IM+3 = 0.00 = (3.70E-4 - 1.00 * 5.40E-6 - 1.00 * 3.65E-4 - 0.00 * 2.19E-2)

/(1.00 - 1.11E-2)

IM+4 = 0.00 = (1.38E-6 - 1.00 * 1.51E-8 - 1.00 * 1.36E-6 - 0.00 * 1.23E-4

- 0.00 * 1.11E-2)/(1.00 - 0.00)

  1. The example involves a four-carbon molecule with 13C-labeling involving a single carbon 50% of the time. Each row represents a single application (step) of Equation 5. All numbers rounded to three significant figures.
  2. bCorrected isotopologue values. The use of these values in subsequent steps is highlighted in bold.
  3. cContaminated isotopologue values.