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Development and evaluation of low-temperature plasma (LTP) for organic matter and aerosol analyses by FTICR mass spectrometry


EMSL Project ID
60507

Abstract

The analyses of various forms of organic matter (OM) and secondary organic aerosols (SOA) by high-resolution mass spectrometry (e.g., FTICR MS) has found great utility in broadly characterizing classes of molecules ranging from polar to nonpolar. However, several ionization sources including electrospray ionization (ESI) and atmospheric pressure chemical ionization or photoionization (APCI or APPI) must be utilized for truly comprehensive MS studies due this diverse chemical composition. This requires not only larger volumes of sample, but also several different forms of sample preparation for the best results. Recently, ambient ionization (i.e., nanoDESI) was demonstrated for the direct characterization of intact SOA filters, and other OM. This technique vastly reduces the amount of consumed sample and eliminates the need for sample preparation. However, much like traditional ESI analyses there is a general trend exhibited for the efficient ionization and subsequent detection of more polar molecules. To this end we are proposing to design, develop, and evaluate the utility of a low-temperature plasma (LTP) source for complementary direct ambient analyses of OM. LTP has been previously demonstrated to not only analyze semi-volatile polar molecules detectable by nanoDESI, but also nonpolar and aromatic molecules within the same analysis, thus expanding the range of detectable compounds by direct ambient ionization. After development and construction of the source, the platform will be evaluated for the characterization of whole soils and intact aerosol filters by FTICR MS. This capability will have broad impacts within direct analysis workflows of OM/SOA, and also has potential to support niche MSI applications of semi-volatile molecules.

Project Details

Start Date
2022-06-02
End Date
2023-05-01
Status
Closed

Team

Principal Investigator

Kevin Zemaitis
Institution
Environmental Molecular Sciences Laboratory

Team Members

Gregory Vandergrift
Institution
Pacific Northwest National Laboratory

William Kew
Institution
Environmental Molecular Sciences Laboratory

Carter Bracken
Institution
Environmental Molecular Sciences Laboratory