Fig. 5
a Comparison of the correction matrices for natural abundance before and after deconvolution of acetyl-CoA using the ULS method. FAM from labeled samples is from Ref. [10]. The left panel shows the correction matrix used in Ref. [10], and the right panel shows the correction matrix used in ElemCor. Matrices are truncated to show the first six rows and columns for illustration purposes. b Combinations of oxygen atoms included in the correction matrix for different methods. The example is for glutamine at an instrument resolution of 100,000. Note that the total mass excess over base mass due to the heavy isotopes of oxygen should not exceed the number of tracer (carbon) atoms in the molecule