Combined corona discharge and UV photoionization source for ion mobility spectrometry

Bahrami, Hamed; Tabrizchi, Mahmoud

doi:10.1016/j.talanta.2012.04.052

Cited by 24 publications

(18 citation statements)

References 34 publications

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“…15 Recently, Tabrizchi described an ion mobility spectrometer equipped with an atmospheric pressure photoionization and a corona discharge ionization source and observed peaks from either the corona discharge or photoionization individually or simultaneously, which makes it possible to accurately compare peaks in the ion mobility spectra from each individual source. 16 Positive photoionization ion mobility spectrometry was mostly applied in the detection of compounds with ionization potential (IP) lower than the energy of photons. Explosive compounds, such as ammonium nitrate, 2,4,6-trinitrotoluene, and pentaerythritol tetranitrate, are salts or molecules with strong electrophilic groups −NO 2 and −ONO 2 , and their IPs are too high to be ionized commercially by available krypton or hydrogen discharge lamp, but they can be easily and sensitively detected by negative mode ion mobility spectrometry due to their large positive electron affinities.…”

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confidence: 99%

Dopant-Assisted Negative Photoionization Ion Mobility Spectrometry for Sensitive Detection of Explosives

et al. 2012

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Ion mobility spectrometry (IMS) is a key trace detection technique for explosives and the development of a simple, stable, and efficient nonradioactive ionization source is highly demanded. A dopant-assisted negative photoionization (DANP) source has been developed for IMS, which uses a commercial VUV krypton lamp to ionize acetone as the source of electrons to produce negative reactant ions in air. With 20 ppm of acetone as the dopant, a stable current of reactant ions of 1.35 nA was achieved. The reactant ions were identified to be CO 3by atmospheric pressure time-of-flight mass spectrometry, while the reactant ions in 63 Ni source were O 2. Finally, its capabilities for detection of common explosives including ammonium nitrate fuel oil (ANFO), 2,4,6-trinitrotoluene (TNT), N-nitrobis(2-hydroxyethyl)amine dinitrate (DINA), and pentaerythritol tetranitrate (PETN) were evaluated, and the limits of detection of 10 pg (ANFO), 80 pg (TNT), and 100 pg (DINA) with a linear range of 2 orders of magnitude were achieved. The time-of-flight mass spectra obtained with use of DANP source clearly indicated that PETN and DINA can be directly ionized by the ion-association reaction of CO 3 − to form PETN·CO 3 − and DINA·CO 3 − adduct ions, which result in good sensitivity for the DANP source. The excellent stability, good sensitivity, and especially the better separation between the reactant and product ion peaks make the DANP a potential nonradioactive ionization source for IMS.

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Dopant-Assisted Negative Photoionization Ion Mobility Spectrometry for Sensitive Detection of Explosives

et al. 2012

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“…3(right). Figure 4 shows the negative reactant ions produced using a radioactive ionization source in combination with the 10 [42][43][44]. When 315 ppm of acetone (9.703 eV ionization potential) was added to the carrier gas, the negative reactant ions of Fig.…”

Section: Methodsmentioning

confidence: 99%

“…From the beginning, comparative evaluation of the ionization sources on a common platform was pursued, similar to the more recent theme of using multiple ionization sources in a single IMS or IMMS to enhance analytical capabilities [12,13]. Unlike the radioactive ionization source, the discharge and photo-ionization sources are non-equilibrium sources with electron temperatures or photon energies exceeding gas temperature.…”

Section: Introductionmentioning

confidence: 99%

Molecular modeling interpretation of IMMS data collected on negative ionization of methyl salicylate using radioactive, corona discharge and photo-ionization

Spangler¹

2015

Int. J. Ion Mobil. Spec.

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Except for electrospray ionization that was introduced later to handle biochemical analyses, the radioactive source has been the benchmark ionization source for ion mobility spectrometry. On the other hand, the licensing requirements accompanying the use of the source has created a desire to replace it with a nonradioactive source with an equivalent ionization capability. Two such sources are the discharge and photoionization sources that are capable of negatively ionizing the internally hydrogen bonded ketoB isomer of methyl salicylate. IMMS data show that if the negative reactant ions are NO 3 − ·HNO 3 (discharge source) or CO 3 − (doped photoionization source), methyl salicylate cannot be ionized. However when the sources are synchronously pulsed with a shutter grid, methyl salicylate can be ionized by the formation of the oxygen anion adduct, O 2 − ·M, similar to radioactive ionization. The ionization capability depends not only upon the partial concentration of oxygen in the immediate ionization region but also on the geometry used to construct the source. Molecular modeling shows that the UV radiation emitted by the sources will photodissociate the reactant ions that reconstitute as the energy of the UV radiation decreases during the pulsing cycle. The reconstitution of CO 3 − is delayed due to a change in geometric symmetry and is the first to leave the ionization region because of its high mobility. This allows methyl salicylate to be ionized by oxygen anions.

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“…An ion mobility spectrometer with a radioactive ionization source and UV, as well as a multicapillary column, was used for the determination of methyl tert-butyl ether (MTBE) and monoaromatic compounds (benzene, toluene, and m-xylene) in water [13]. The use of an ion mobility spectrometer equipped with two sources of ionization, i.e., lamp for atmospheric pressure photoionization (APPI) and corona discharge system, allowed for a significant enrichment of the analytical information contained in the drift-time spectra [83]. In recent years, prototypes of DMS detectors equipped with an APPI ion source have been designed where D is the dopant molecule and M is the analyte molecule.…”

Section: Dopants Used In Uv Ionization Detectorsmentioning

confidence: 99%

Dopants and gas modifiers in ion mobility spectrometry

Waraksa

Perycz

Namieśnik

et al. 2016

TrAC Trends in Analytical Chemistry

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Combined corona discharge and UV photoionization source for ion mobility spectrometry

Cited by 24 publications

References 34 publications

Dopant-Assisted Negative Photoionization Ion Mobility Spectrometry for Sensitive Detection of Explosives

Dopant-Assisted Negative Photoionization Ion Mobility Spectrometry for Sensitive Detection of Explosives

Molecular modeling interpretation of IMMS data collected on negative ionization of methyl salicylate using radioactive, corona discharge and photo-ionization

Dopants and gas modifiers in ion mobility spectrometry

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