Development of a Structure for Lossless Ion Manipulations (SLIM) High Charge Capacity Array of Traps

• Published in: Analytical chemistry (Washington) 2023-03, Vol.95 (9), p.4446-4453
• Main Authors: Huntley, Adam P., Hollerbach, Adam L., Prabhakaran, Aneesh, Garimella, Sandilya V. B., Giberson, Cameron M., Norheim, Randolph V., Smith, Richard D., Ibrahim, Yehia M.
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Arrays; Chemistry; Controllability; high resolution; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Ion charge; ion mobility spectrometry; ion trap; Ion traps (instrumentation); Ionic mobility; Ions; mass spectrometry; Mobility; Populations; Sensitivity enhancement; SLIM; Traps; traveling waves
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/acs.analchem.2c05025

Enhancing the sensitivity of low-abundance ions in a complex mixture without sacrificing measurement throughput is highly desirable. This work demonstrates a way to greatly improve the sensitivity of ion mobility (IM)-selected ions by accumulating them in an array of high-capacity ion traps located inside a novel structures for lossless ion manipulations ion mobility spectrometer (SLIM-IMS) module. The array of ion traps used in this work consisted of seven independently controllable traps. Each trap was 386 mm long and possessed a charge capacity of ∼4.5 × 108 charges, with a linear range extending to ∼2.5 × 108 charges. Each ion trap could be used to extract a peak (or ions over a mobility range) from an ion mobility separation based on arrival time. Ions could be stored without losses for long times (>100 s) and then released all at once or one trap at a time. It was possible to accumulate large ion populations by extracting and storing ions over repeated IM separations. Enrichment of up to seven individual ion distributions could be performed using the seven independently controllable ion traps. Additionally, the ion trapping process effectively compressed ion populations into narrow peaks, which provides a greatly improved basis for subsequent ion manipulations. The array of high charge capacity ion traps provides a flexible addition to SLIM and a powerful tool for IMS-MS applications requiring high sensitivity.