Available Technology

Methods for Near Real-time Chemical Analysis of Aerosols using Microwave-induced Plasma Spectroscopy

This CDC developed technology entails a novel method of near real-time elemental analysis of aerosols by corona assisted microwave induced plasma spectroscopy (CAMPS). Analysis of elemental composition of aerosol particles holds significant implications for environmental and workplace pollution monitoring. Various plasma based analytical techniques, including laser-induced breakdown spectroscopy (LIBS) and spark-induced breakdown spectroscopy (SIBS), have been successfully used for multi-elemental analyses in solids, liquids, and gases, including aerosols. However, the characterization of fine and ultrafine aerosols using these techniques is particularly challenging due to small plasma volume, miniscule sample mass, and inferior sampling statistics, often leading to poor detection limits and precision. This technology utilizes a microwave plasma-based detection system for aerosol analysis that features increased microplasma lifetime, repeatability, and stability over currently-available pulsed microplasma-based methods. This system produces microplasma lifetimes in the range of 5 to 50 milliseconds, a duration that is orders of magnitude larger than lifetimes for laser-induced or spark plasmas, as well as larger plasma volumes, which together are expected to provide improved detection limits over currently-available techniques.
Patent Abstract: 
This CDC developed technology entails a novel method of near real-time elemental analysis of aerosols by corona assisted microwave induced plasma spectroscopy (CAMPS). Analysis of elemental composition of aerosol particles holds significant implications for environmental and workplace pollution monitoring. Various plasma based analytical techniques, including laser-induced breakdown spectroscopy (LIBS) and spark-induced breakdown spectroscopy (SIBS), have been successfully used for multi-elemental analyses in solids, liquids, and gases, including aerosols. However, the characterization of fine and ultrafine aerosols using these techniques is particularly challenging due to small plasma volume, miniscule sample mass, and inferior sampling statistics, often leading to poor detection limits and precision. This technology utilizes a microwave plasma-based detection system for aerosol analysis that features increased microplasma lifetime, repeatability, and stability over currently-available pulsed microplasma-based methods. This system produces microplasma lifetimes in the range of 5 to 50 milliseconds, a duration that is orders of magnitude larger than lifetimes for laser-induced or spark plasmas, as well as larger plasma volumes, which together are expected to provide improved detection limits over currently-available techniques.
Benefits 
Makes it possible to conduct accurate, near-real-time measurement of the elemental composition of aerosols in industrial and ambient atmospheres -Corona field stabilizes the microwave plasma and results in repeatable plasma formation -Larger size of CAMPS plasma provides sufficient plasma volume which can lead to complete ablation of deposited aerosol in the tip of the electrode -Longer duration of CAMPS plasma (~10-50 ms) allows longer integration time which results in signal enhancement
applications 
Inventors: 
Pramod Kulkarni
Patent Number: 
13/804,512
Internal Laboratory Ref #: 
E-163-2013/0
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