Basic Information
Abstract Number: 1780-1    
Author Name: Keqi Tang Affiliation: Pacific Northwest National Laboratory
Session Title: Achievements and Challenges in Mass Spectrometry
Event Type: Symposia
Event Title: Advancing ESI-MS Interface Technologies for High Sensitivity Proteomics
Presider(s): Thurman, Michael Start Time: 08:05 AM ( Slot # 2 )
Date: Thursday, March 17th, 2011 Location: 310B
Keywords: Electrospray, Instrumentation, Liquid Chromatography/Mass Spectroscopy, Mass Spectrometry

Kelly, Ryan TPacific Northwest National Laboratory
Marginean, IoanPacific Northwest National Laboratory
Smith, Richard DPacific Northwest National Laboratory

Abstract Content
Achieving high sensitivity in electrospray ionization mass spectrometry (ESI-MS) is critical to the effective analysis of complex biological sample. The sensitivity of ESI-MS is largely determined by the gas-phase ion production rate in the ESI source (ionization efficiency) and the ability to transfer analyte ions from ion source to MS detector (ion transmission efficiency). The most ion loss in the conventional ESI-MS instrument is in the interface region. The ion transmission through this interface is essentially limited by the small sampling inlet (typically 400 to 500 um in diameter as required to maintain a good vacuum pressure in MS analyzer chamber) resulting in a <1% overall ion transmission efficiency or ~99% ion loss in the interface region. This low interface ion transmission efficiency can be significantly improved by using the new interface technologies including ESI emitter array, multicapillary inlet, electrodynamic ion funnel and subambient pressure ESI source. Some of the new interface technologies have been successfully implemented on the commercial MS products while others are still evolving. This presentation will start with a brief discussion of the ion funnel operation principle and its unique features to allow effective ion focusing and transmission in the ESI-MS interface region followed by a detailed description of the critical components in the new ESI-MS interfaces. The discussion will then be switched to our recent experimental evaluation of the new ESI-MS interfaces on several MS platforms to achieve high sensitivity in proteomic sample analysis with focus on the significantly improved limit of quantitation on a triple quadrupole MS.