Structure selective ion molecule interactions (SSIMI) in ion mobility spectrometry

Autor: Ching Wu, Charles S. Harden, Herbert H. Hill, Kristyn M. Roscioli, Anthony J. Midey, Manuja R. Lamabadusuriya, William F. Siems
Rok vydání: 2013
Předmět:
Zdroj: International Journal for Ion Mobility Spectrometry. 17:43-53
ISSN: 1865-4584
1435-6163
DOI: 10.1007/s12127-013-0143-3
Popis: The overall objective of this project was to develop an analytical method that utilizes structure selective ion molecule interactions (SSIMI) in ion mobility spectrometry (IMS) to shift the mobility of a targeted analyte through the addition of a gas phase modifier to the buffer gas. IMS is a sensitive, rapid method for the detection of harmful chemicals; however false alarm responses do occur and a reduction in their frequency decrease both the cost and time required for detection. The investigation reported here probed the effects of a series of buffer gas modifiers on the mobilities of chemical warfare agent simulants (CWAs), toxic industrial chemicals (TICs) and a known interference (butyl carbitol) found in fire extinguishing agents. The major finding of this research was that a modifier with a proton affinity similar to, but not greater than, the target analyte produced the greatest changes in mobilities due to the formation of an ion cluster between the neutral modifier and target analyte ion. Mass spectrometry was utilized to confirm the formation of ion-neutral clusters that caused the target ion to shift its mobility. While a number of modifiers were screened, acetonitrile and isobutyronitrile were found to have sufficiently selective SSIMI with the target compound. For example, in the presence of acetonitrile modifier, the protonated response ion of the CWA simulant DMMP, [DMMP]H+, had a mobility shift of 10.8 %, but the mobility was unchanged for the interferent, butyl carbitol. The mobility of the simulant DMMP decreased with the introduction of modifiers, while the mobility of the interference did not change, demonstrating the potential of the SSIMI technique for reducing false alarm rates.
Databáze: OpenAIRE
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