Characterization of a Distributed Plasma Ionization Source (DPIS) for Ion Mobility Spectrometry and Mass Spectrometry

Journal Article · Wed Oct 15 00:00:00 EDT 2008 · Talanta, 77(1):249-255

DOI:https://doi.org/10.1016/j.talanta.2008.06.014· OSTI ID:959194

Waltman, Melanie J; Dwivedi, Prabha; Hill, Herbert; Blanchard, William C; Ewing, Robert G

A recently developed atmospheric pressure ionization source, a distributed plasma ionization source (DPIS), was characterized and compared to commonly used atmospheric pressure ionization sources with both mass spectrometry and ion mobility spectrometry. The source consisted of two electrodes of different sizes separated by a thin dielectric. Application of a high RF voltage across the electrodes generated plasma in air yielding both positive and negative ions depending on the polarity of the applied potential. These reactant ions subsequently ionized the analyte vapors. The reactant ions generated were similar to those created in a conventional point-to-plane corona discharge ion source. The positive reactant ions generated by the source were mass identified as being solvated protons of general formula (H2O)nH+ with (H2O)2H+ as the most abundant reactant ion. The negative reactant ions produced were mass identified primarily as CO3-, NO3-, NO2-, O3- and O2- of various relative intensities. The predominant ion and relative ion ratios varied depending upon source construction and supporting gas flow rates. A few compounds including drugs, explosives and environmental pollutants were selected to evaluate the new ionization source. The source was operated continuously for several months and although deterioration was observed visually, the source continued to produce ions at a rate similar that of the initial conditions. The results indicated that the DPIS may have a longer operating life than a conventional corona discharge.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 959194
• Report Number(s): PNNL-SA-60197; TLNTA2; TRN: US1000062
• Journal Information: Talanta, 77(1):249-255, Vol. 77, Issue 1; ISSN 0039-9140
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANIONS
ATMOSPHERIC PRESSURE
CONSTRUCTION
CORONA DISCHARGES
ELECTRODES
EXPLOSIVES
GAS FLOW
ION MOBILITY
ION SOURCES
IONIZATION
MASS SPECTROSCOPY
PLASMA
POLLUTANTS
PROTONS
SPECTROSCOPY
distributed plasma ionization source
atmospheric pressure ionization
ion mobility spectrometry
mass spectrometry
corona discharge
explosives and drugs