Metabolite Spectral Accuracy on Orbitraps

Su, X.; Lu, W.; Rabinowitz, J.D.

Spectral accuracy is an important metric of mass spectrometer performance, reflecting the ability to accurately quantify labeled forms. Rabinowitz et al. identify potential systematic errors in spectral accuracy that occur in high resolution Orbitrap measurements. These are fixed with proper choice of mass scan window together with a novel isotope correction algorithm – AccuCor (open source). The theory and experimental utility is described, the latter of which was evaluated with isotope-labeled metabolites from a yeast cell extract. The combined experimental and computational advances were found to provide accurate labeling quantitation for metabolic flux analyses.