多柱耦合提高Nano-ESI-MS的色谱分离

　　Coupling columns of same or different resin materials is often employed in complex proteomic digest analysis. Despite enhanced separation, these multidimensional columns are costly, timeconsuming to produce, and initiate post-column loss by deadvolume introduction. Confounding factors of column-coupling can be eliminated via transparent, true zero-dead-volume (ZDV) unions that achieve flush connections and rapid swap-out facility during system maintenance. In the current investigation, two conventional 10 cm-bedded columns were coupled and connected to the bed terminus of a third 10 cm nanobore column with integrally fritted tip. Analytical merit of this extended column was compared with a single 30 cm-bedded column with integrally fritted tip and the same resin material. These novel unions supported chromatographic data collection with zero dead-volume, negligible resolution loss, and comparable caliber as the single 30 cm-bedded column. The performance of a 35 cm column fabricated from 15- and 20-columns is also detailed.