APPLICATION OF SEQUENTIAL PAIRED COVARIANCE TO CAPILLARY ELECTROPHORESIS ELECTROSPRAY-IONIZATION TIME-OF-FLIGHT MASS-SPECTROMETRY - UNRAVELING THE SIGNAL FROM THE NOISE IN THE ELECTROPHEROGRAM

The combination of capillary electrophoresis (CE) with electrospray ionization (ESI) time-of-night mass spectrometry (TOF-MS) has recently been demonstrated, When CE is combined with TOF-MS using an electrospray interface, the method provides fast, high-resolution separations with rapid mass analysis and the potential for very high sensitivity. In analyzing the data, one first reconstructs an electropherogram from the data set and then identifies peaks in the mass spectra, The mass spectra corresponding to the peaks in the electropherogram are then inspected to enable solute identification. However, background noise often prevents detection of peaks in the reconstructed electropherogram, thus interfering with the analysis, In this work we demonstrate alternative electropherogram reconstruction techniques that enhance its signal-to-noise ratio, allowing more immediate identification of the number of components in a mixture and their corresponding retention times, The techniques described here should also be adaptable for on-line analysis of CE-ESI-TOF data and the combination with other separation techniques coupled to mass spectrometry (e,g,, LC/MS), as well as any multichannel detection scheme.