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In 1938, Walker Bleakney and John A. Hipple first described the cycloidal mass analyzer as the only mass analyzer configuration capable of “perfect” ion focusing. Why has their geometry been largely neglected for many years and how might it earn a respectable place in the world of modern chemical analysis? This Perspective explores the properties of the cycloidal mass analyzer and identifies the lack of suitable ion array detectors as a significant reason why cycloidal mass analyzers are not widely used. The recent development of capacitive transimpedance amplifier array detectors can enable several techniques using cycloidal mass analyzers including spatially coded apertures and single particle mass analysis with a “virtual-slit”, helping the cycloidal mass analyzer earn a respectable place in chemical analysis.
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This content will become publicly available on June 1, 2026
Control system for an underwater coded aperture miniature mass spectrometer
In situ measurements of the spatiotemporal distribution of dissolved gases in the ocean are useful for a wide variety of applications including monitoring biogeochemical cycles (e.g., methane, oxygen, and carbon dioxide fluxes), detecting pollutants, studying submarine groundwater discharge, and tracking chemical gradients in water columns or sediment interfaces. Over the past two decades, underwater membrane inlet mass spectrometry has emerged as a leading technology for in situ dissolved gas analysis, leveraging various mass analyzers such as quadrupole, ion trap, and cycloidal systems. While quadrupoles and ion traps face challenges such as water vapor interference and resolution limitations, cycloidal analyzers offer higher resolution at low mass-to-charge ratios with reduced power requirements. However, they have historically suffered from sensitivity and sequential analysis limitations. Recent advances, including ion array detectors and computational sensing, now enable simultaneous mass detection and improved sensitivity in cycloidal mass analyzers. This study introduces the development of an underwater coded aperture miniature mass spectrometer (UW-CAMMS), incorporating a cycloidal mass analyzer, ion array detector, and spatially coded apertures. A low-power electronic control system for the UW-CAMMS is designed and characterized, with performance comparable to laboratory-based systems, showcasing progress toward efficient, compact underwater dissolved gas monitoring. This technology can be used to study dynamic processes in marine, freshwater, and brackish systems with high spatial and temporal resolution.
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- Award ID(s):
- 2123556
- PAR ID:
- 10626834
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Green Analytical Chemistry
- Volume:
- 13
- Issue:
- C
- ISSN:
- 2772-5774
- Page Range / eLocation ID:
- 100241
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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