Open AccessImproving Ion Mobility Measurement Sensitivity by Utilizing Helium in an Ion Funnel Trap
Author(s) -
Yehia Ibrahim,
Sandilya Garimella,
Aleksey V. Tolmachev,
Erin Baker,
Richard Smith
Publication year - 2014
Publication title -
analytical chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.117
H-Index - 332
eISSN - 1520-6882
pISSN - 0003-2700
DOI - 10.1021/ac404250z
Subject(s) - chemistry , ion , buffer gas , helium , funnel , inert gas , ion trap , drift tube , ion mobility spectrometry , trap (plumbing) , analytical chemistry (journal) , nitrogen , atomic physics , mass spectrometry , signal (programming language) , chromatography , optics , laser , physics , organic chemistry , environmental engineering , computer science , programming language , engineering
Ion mobility instruments that utilize nitrogen as buffer gas are often preceded by an ion trap and accumulation region that also uses nitrogen, and for different inert gases, no significant effects upon performance are expected for ion mobility spectrometry (IMS) of larger ions. However, we have observed significantly improved performance for an ion funnel trap upon adding helium; the signal intensities for higher m/z species were improved by more than an order of magnitude compared to using pure nitrogen. The effect of helium upon IMS resolving power was also studied by introducing a He/N2 gas mixture into the drift cell, and in some cases, a slight improvement was observed compared to pure N2. The improvement in signal can be largely attributed to faster and more efficient ion ejection into the drift tube from the ion funnel trap.