Abstract
This paper presents a novel combination of of-line liquid chromatography (LC) separation with desorption ionization on silicon mass spectrometry (DIOS-MS) as an alternative to the traditional on-line coupling of LC and electrospray ionization (ESI). In this work, electrospray deposition is used to generate a spatially preserved linear track of the separated sample on a specially designed DIOS chip. The total sequence coverage analysis of two model protein systems was evaluated by both LC-DIOS-MS and nanoLC ESI tandem MS (MS/MS). LC-DIOS-MS yielded improved sequence coverage for both of the model systems (between 99.5 and 100%) compared with traditional LC-ESI-MS/MS analysis (between 82 and 87.6%). In addition to improved sequence coverage determination, LC-DIOS-MS also offers the potential for high-throughput protein characterization.