Improved Ion Transmission from Atmospheric Pressure to High Vacuum Using a Multicapillary Inlet and Electrodynamic Ion Funnel Interface

摘要

A heated multicapillary inlet and ion funnel interface was develped to couple an electrospray ionization(ESI) source to a high-vacuum stage for obtaining improved sensitivity in mass spedtrometric applications. The inlet was constructed from an array of seven thin-wall stainless stell tubes soldered into a central hole of a cylindrical hiating block. An electrodynamic ion funnel was used in the interface region to more effctively capture, focus, and transmit ions from th multicapillary inlet. The intertface of seven cpaillary inlets with the ion funnel showed more than 7 times higher transmission efficiency compared to that of a single capillary inlet with the ion funnel and a 23-fold greater transmission efficiency tha could be obtained using the standard orifice-skimmer interface of a trple-quadrupole MS. The multiple-capillary inlet and ion funnel interface showed an overall 10% ion transmission efficency and approximately 3-4% overall detection efficiency of ions from solution based(i.e., prior to electrosprray). The improved performance was achieved under conditions where ESI operation is robust and result in a significant icrease in dynamic range.