title: Inductively Coupled Plasma Zoom-Time-of-Flight Mass Spectrometry.
abstract: A zoom-time-of-flight mass spectrometer has been coupled to an inductively coupled plasma (ICP) ionization source. Zoom-time-of-flight mass spectrometry (zoom-TOFMS) combines two complementary types of velocity-based mass separation. Specifically, zoom-TOFMS alternates between conventional, constant-energy acceleration (CEA) TOFMS and energy-focused, constant-momentum acceleration (CMA) (zoom) TOFMS. The CMA mode provides a mass-resolution enhancement of 1.5-1.7× over CEA-TOFMS in the current, 35-cm ICP-zoom-TOFMS instrument geometry. The maximum resolving power (full-width at half-maximum) for the ICP-zoom-TOFMS instrument is 1200 for CEA-TOFMS and 1900 for CMA-TOFMS. The CMA mode yields detection limits of between 0.02 and 0.8 ppt, depending upon the repetition rate and integration time-compared with single ppt detection limits for CEA-TOFMS. Isotope-ratio precision is shot-noise limited at approximately 0.2% relative-standard deviation (RSD) for both CEA- and CMA-TOFMS at a 10 kHz repetition rate and an integration time of 3-5 min. When the repetition rate is increased to 43.5 kHz for CMA, the shot-noise limited, zoom-mode isotope-ratio precision is improved to 0.09% RSD for the same integration time.
authors.affiliation: Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA.
authors.forename: Elise A
authors.initials: EA
authors.lastname: Dennis
authors.affiliation: Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Ray
authors.affiliation: Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM, 87131, USA.
authors.forename: Christie G
authors.initials: CG
authors.lastname: Enke
authors.affiliation: Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA. hieftje@indiana.edu.
authors.forename: Gary M
authors.initials: GM
authors.lastname: Hieftje
mesh_terms: D004602:Elements; D004867:Equipment Design; D007554:Isotopes / Q000032:analysis; D013058:Mass Spectrometry / Q000295:instrumentation* / Q000379:methods
chemical_list: D004602:Elements; D007554:Isotopes
keywords: Inductively coupled plasma; Mass spectrometry; Time-of-Flight; Zoom-TOF