Increased applications of fluorochemicals have prompted development of elemental methods for detection and quantitation of these compounds. However, high-sensitivity detection of fluorine is a challenge because of difficulties in excitation and ionization of this element. Recently, a new approach has emerged to detect F as a diatomic ion (BaF+) in inductively coupled plasma mass spectrometry (ICP-MS). However, formation of this species in the high-temperature plasma is inefficient, leading to low sensitivities. Here, we introduce a post-ICP chemical ionization approach to enhance analytical performance for F detection in liquid samples. Solutions of fluorochemicals are introduced into an ICP leading to formation of HF in the afterglow. Subsequently, reagent ions from nanospray of sodium acetate and barium acetate electrolytes are utilized to ionize HF to Na2F+ and BaF+, respectively, via post-plasma ion-neutral reactions. Both ions provide substantially better sensitivities compared to that of BaF+ formed inside the plasma in conventional ICP-MS methods. Notably, post-plasma BaF+ offers a sensitivity of 280 cps/ppb for F, near two orders of magnitude higher than that of conventional ICP-MS methods. Compound-independent response for F from structurally diverse organofluorines is confirmed by monitoring BaF+ and a limit of detection (LOD) of 8–11 ng/mL F is achieved. Importantly, isobaricmore »
Multi-functional Vacuum Ionization Source for MAI, LSI, and MALDI: Operational from AP for Comprehensive, Low-Cost Data-Mining in Mass Spectrometry
Unprecedented ionization processes developed into powerful methods have attributes highly desirable for MS and include high sensitivity, low cost, simplicity, ability to directly analyze biological and synthetic materials, potential for high throughput, automation, exceptional robustness, and wide applicability, especially in environments outside analytical laboratories. Initial matrix-assisted ionization (MAI) results showed different selectivity relative to ESI or MALDI providing information not readily obtained with current methodologies. Here, we demonstrate the first vacuum ionization source with multi-ionization capabilities on the same high-resolution API-mass spectrometer for a range of analytical problems with sensitivity in low fmol and detection limit in low amol ranges. The potential for achieving MS and MS/MS analysis speeds of ca. 4 seconds/sample in a simple low-cost fashion is demonstrated.
- Authors:
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Award ID(s):
- 1913787
- Publication Date:
- NSF-PAR ID:
- 10203086
- Journal Name:
- 68th Annual ASMS Conference on Mass Spectrometry and Allied Topics
- Sponsoring Org:
- National Science Foundation
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