Improving ion mobility measurement sensitivity by utilizing helium in an ion funnel trap.
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.
Biological Sciences Division, Pacific Northwest National Laboratory , P.O. Box 999, Richland, Washington 99352, United States.
Yehia M
YM
Ibrahim
Sandilya V B
SV
Garimella
Aleksey V
AV
Tolmachev
Erin S
ES
Baker
Richard D
RD
Smith
D000465:Algorithms; D002021:Buffers; D006371:Helium / Q000032:analysis*; D007477:Ions / Q000737:chemistry; D013058:Mass Spectrometry; D009584:Nitrogen / Q000737:chemistry; D011492:Protein Hydrolysates / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry
D002021:Buffers; D007477:Ions; D011492:Protein Hydrolysates; D006371:Helium; D012710:Serum Albumin, Bovine; D009584:Nitrogen