Relative quantitation of phosphatidylcholines with interfered masses of protonated and sodiated molecules by matrix-assisted laser desorption/ionization mass spectroscopy

Abstract

This work presents a computational method for deconvolution of interfered peaks of protonated and sodiated phosphatidylcholines (PCs) to solve the problem of relative quantitation of these PCs. The method is based on the fact that adducts of PCs with proton and sodium ion give unique characteristic peaks in tandem mass spectra. The intensities of these peaks were used to find out contribution of protonated and sodiated PCs to the formation of interfered peak in full-scan mass spectrum and, further, to correlate peak intensities that correspond to PCs in fullscan mass spectrum with PC’s concentrations. The model was calibrated on synthesized PCs and verified for applicability in the range of Na+ ion concentrations from trace to physiological one.