High throughput analytical systems and methods employing multiple liquid phase separation process regions coupled to a common mass spectrometer are provided. Disclosed systems and methods permits parallel separation and parallel storage of discrete eluate fractions, followed by sequential discharge and ionization of previously stored eluate portions to yield a composite ion stream containing the sequential series of eluate portions, followed by mass analysis of the ion stream. A common manifold may receive ions and utilize pressurized gas or ion gating to direct ions within the manifold toward the mass spectrometer inlet.