PNNL

Abstract

A heated multi-capillary inlet and ion funnel interface was developed to an ionization (ESI) source to a high vacuum stage for obtaining improved sensitivity in mass spectromic applications. The multi-capillary inlet was constructed from an array of seven thin wall stainless steel tubes soldered into a central hole of a cylindrical heating block. An electrodynamic ion funnel was used in the interface region to more effectively capture, focus, and transmit ions from the multi-capillary inlet. The interface of seven capillary inlet with ion funnel showed more than seven times higher transmission efficiency compared to that of a single capillary inlet with the ion funnel, and a 23-fold greater transmission efficiency than could be obtained using the standard orifice-skimmer interface of a triple quadrupole MS. The multiple capillary inlet and ion funnel interface showed an overall 10% ion transmission efficiency and approximately 3 to 4% overall detection efficiency of.based (i.e. prior to electrospray). The improved performance was achieved under conditions where ESI operation is robust and results in a significant increase in dynamic range.