Damping Factor Links Periodic Focusing and Uniform Field Ion Mobility for Accurate Determination of Collision Cross Sections

• Published in: Analytical chemistry (Washington) Vol. 84; no. 6; pp. 2818 - 2824
• Main Authors: Silveira, Joshua A, Jeon, Junho, Gamage, Chaminda M, Pai, Pei-Jing, Fort, Kyle L, Russell, David H
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 20.03.2012
• Subjects: Analytical chemistry; Animals; Cattle; Chemistry; Exact sciences and technology; Horses; Ions; Ions - chemistry; Mass spectrometry; Mass Spectrometry - methods; Peptides; Peptides - chemistry; Proteins; Proteins - chemistry; Spectrometric and optical methods; Design; Ion collision; Ion mobility spectroscopy; Ion mobility; Peptides; Ion spectrometry; Cross section (collision); Protein; Operating conditions
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac203294q

The methodology for obtaining accurate ion-neutral collision cross section (Ω) values for peptides and proteins using periodic focusing ion mobility spectrometry (PF IMS) is presented. A mobility dampening factor (represented by the term α) is introduced to account for the relative increase in ion-neutral collisions in PF IMS compared to uniform field ion mobility spectrometry (UF IMS) for equivalent operating conditions. The results show that α may be easily quantified both theoretically and empirically for a specific PF IMS design operating at a given pressure based upon the charge state of the analyte. By simply incorporating an α term into traditional UF IMS expressions, accurate Ω values were obtained with excellent agreement (≤4% difference) compared to UF IMS measurements found in the current literature.