Fully automated four-column capillary LC-MS system for maximizing throughput in proteomic analyses

We describe a four-column, high-pressure capillary liquid chromatography (ILC) system for robust, high-throughput liquid chromatography-mass specbrometry (LC-MS(/MS)) analyses. This system performs multiple LC separations in parallel, but staggers each of them such that the data-rich region of each separation is sampled sequentially. By allowing nearly continuous data acquisition, this design maximizes the use of the mass spectrometer. Each analytical column is connected to a corresponding ESI emitter in order to avoid the use of postcolumn switching and associated dead volume issues. Encoding translation stages are employed to sequentially position the emitters at the MS inlet. The high reproducibility of this system is demonstrated using consecutive analyses of global tryptic digest of the microbe Shewanella oneidensis.