PNNL

Abstract

Space charge effects produce frequency shifts in Fourier transfoffi1 ion cyclotron resonance (FTICR) mass spectrometry and correction for these shifts is necessary for obtaining accurate mass measurements. We report a novel method for ~btaining accurate mass calibration to correct for space-charge induced mass shifts without the requirement for internal calibrants. The new approach is particularly well suited for electrospray ionization-FTICR mass spectra that contain multiple charge states of the same molecular species. This method, Deconvolution of Coulombic Affected Linearity (DeCAL ), is described and presented with several examples demonstrating the increased mass measurement accuracy obtained. DeCAL will allow more routine high mass accuracy measurements to be made in conjunction with chromatographic separations for complex mixture analysis, obviating the need for internal calibration in many applications.