Ion mobility spectrometer


Ion mobility spectrometer

An ion mobility spectrometer (IMS) is a spectrometer capable of detecting and identifying very low concentrations of chemicals based upon the differential migration of gas phase ions through a homogeneous electric field. IMS devices come in a wide range of sizes (often tailored for a specific application) and are capable of operating under a broad range of conditions. Systems operated at higher pressure (i.e. atmospheric conditions, 1 atm or 760 Torr) are also accompanied by elevated temperature (above 100°C), while lower pressure systems (1-20 Torr) do not require heating. Elevated temperature assists in removing ion clusters that may distort experimental measurements.

Operation

In its simplest form an IMS system measures how fast a given ion moves in a uniform electric field through a given atmosphere. The molecules of the sample need to be ionized, usually by corona discharge, atmospheric pressure photoionization (APPI), electrospray ionization (ESI), or a radioactive source, eg. a small piece of 63Ni or 241Am, similar to the one used in ionization smoke detectors.

In specified intervals, a sample of the ions is let into the drift chamber; the gating mechanism is based on a charged electrode working in a similar way as the control grid in triodes works for electrons. For precise control of the ion pulse width admitted to the drift tube, more complex gating systems such as a Bradbury-Nielsen design are employed. Once in the drift tube, ions are subjected to a homogeneous electric field ranging from a few volts per centimeter up to many hundreds of volts per centimeter. This electric field then drives the ions through the drift tube where they interact with the neutral drift molecules contained within the system. Separation of chemical species is achieved based upon the ion mobility (a parameter that is dependent of ion mass, size, and shape) where they arrive at the detector for measurement. Ions are recorded at the detector in order from the fastest to the slowest, generating a response signal characteristic for the chemical composition of the measured sample. Often the detector is a simple Faraday plate, however, more advanced ion mobility instruments are coupled with mass spectrometers where both size and mass information may be obtained simutaneously.

Perhaps ion mobility spectrometry's greatest strength is the speed at which separations occur--typically on the order of 10's of milliseconds. This feature combined with its ease of use, relatively high sensitivity, and highly compact design have allowed IMS as a commercial product to be used as a routine tool for the field detection of explosives, drugs, and chemical weapons. In the pharmaceutical industry IMS is used in cleaning validations, demonstrating that reaction vessels are sufficiently clean to proceed with the next batch of pharmaceutical product. As a research tool ion mobility has also shown great strides towards the analysis of biological materials, specifically, proteomics and metabolomics.

ee also

*Electrical mobility
*Viehland-Mason Theory
*Explosive detection

References

*Bengt Nolting, "Methods in Modern Biophysics", Springer Verlag, 2005, ISBN 3-540-27703-X
*Gary Eiceman & Zeev Karpas, "Ion Mobility Spectrometry", [http://www.crcpress.com/shopping_cart/products/product_detail.asp?sku=2247&p CRC Press] , 2005, ISBN 0-8493-2247-2

External links

Applications
* [http://www.isas.de/en/menu-top/research/research-departments/metabolomics/ Metabolomics at ISAS - Institute for Analytical Sciences]
* [http://www.isas.de/english/menu-top/research/research-departments/metabolomics/projects/process-analysis/ Process analytics]
* [http://www.isas.de/english/menu-top/research/research-departments/metabolomics/projects/cancer/ Lung cancer]
* [http://www.isas.de/english/menu-top/research/research-departments/metabolomics/projects/mold/ Molds and fungi]
* [http://ims.ansci.de/ims_old_www/seite1pro16.htm Decomposition products in high voltage equipment]
* [http://ims.ansci.de/ims_old_www/seite1pro17.htm MTBE]

Method
* [http://ims.ansci.de/ IMS at ISAS - Institute for Analytical Sciences]
* [http://www.isims.org International Society for Ion Mobility Spectrometry]
* [http://ijims.ansci.de/ International Journal for Ion Mobility Spectrometry until 2007]
* [http://www.springer.com/chemistry/analytical/journal/12127 International Journal for Ion Mobility Spectrometry since 2008 bei] [http://de.wikipedia.org/wiki/Springer-Verlag SPRINGER]

Research Groups
* [http://bowers.chem.ucsb.edu/ IMS at UCSB, CA, USA]
* [http://www.indiana.edu/~clemmer/ IMS at IUB, Bloomington, IN, USA]
* [http://www.chemistry.nmsu.edu/eiceman_research/ IMS at NMSU, Las Cruces, NM, USA]
* [http://web.chemistry.gatech.edu/~fernandez/Fernandez_Website/index.htm/ IMS at Georgia Tech, Atlanta, GA, USA]
* [http://hill.chem.wsu.edu/home/ IMS at WSU, Pullman, WA, USA]
* [http://www.vanderbilt.edu/AnS/Chemistry/faculty/bio.php?ID=252/ IMS at Vanderbilt, TN, USA]
* [http://www-robinson.ch.cam.ac.uk/index1.php/ IMS at Cambridge University, UK]
* [http://www.chem.tamu.edu/rgroup/russell/ IMS at TAMU, College Station, TX, USA]

Related companies
* [http://www.bdal.com/cbrn-detection.html Bruker Daltonics - Germany]
* [http://www.environics.fi/ Envioronics - Finland]
* [http://www.gas-dortmund.de/ G.A.S. - Germany]
* [http://www.gesecurity.com/portal/site/GESecurity GE Security - USA]
* [http://www.faims.com/contact.htm ionanalytics - USA]
* [http://www.iut-berlin.info/ IUT - Germany]
* [http://www.ionpro.com/ particle measuring systems - USA]
* [http://www.sionex.com/ SIONEX - USA]
* [http://www.smithsdetection.com/eng/index.php smiths detection - UK]


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Ion mobility spectrometer — IMS installiert in einem ABC Erkundungskraftwagen Ein Ionen Mobilitäts Spektrometer (engl.: ion mobility spectrometer, IMS) ist ein Gerät zur chemischen Analyse. Es war zuerst unter dem Namen Plasma Chromatograph bekannt geworden und zeichnet… …   Deutsch Wikipedia

  • Ion mobility spectrometry-mass spectrometry — (IMS MS) is a method that combines the features of ion mobility spectrometry and mass spectrometry to identify different substances within a test sample.HistoryOn the one hand, ion mobility spectrometry was developed in the 70s and typically… …   Wikipedia

  • Electrical mobility — is the tendency of charged elementary particles (such as electrons or protons) to move, other than engaging in a stationary orbit (for example within a given atom or molecule}. When a charged particle in a gas or liquid is acted upon by a uniform …   Wikipedia

  • Bradbury-Nielsen shutter — A Bradbury Nielsen shutter (or Bradbury Nielsen gate) is a type of electrical ion gate, which was first proposed in an article by Norris Bradbury and Russel A. Nielsen, where they used it as an electron filter. [cite journal | author = Norris E.… …   Wikipedia

  • Ionenmobilitätsspektrometer — IMS installiert in einem ABC Erkundungskraftwagen Ein Ionen Mobilitäts Spektrometer (engl.: ion mobility spectrometer, IMS) ist ein Gerät zur chemischen Analyse. Es war zuerst unter dem Namen Plasma Chromatograph bekannt geworden und zeichnet… …   Deutsch Wikipedia

  • Ionen-Mobilitäts-Spektrometer — IMS installiert in einem ABC Erkundungskraftwagen Ein Ionen Mobilitäts Spektrometer (engl.: ion mobility spectrometer, IMS) ist ein Gerät zur chemischen Analyse. Es war zuerst unter dem Namen Plasma Chromatograph bekannt geworden und zeichnet… …   Deutsch Wikipedia

  • Corona discharge — The corona discharge around a high voltage coil …   Wikipedia

  • IMS — may refer to:Organizations and institutes* IMS Global, a non profit standards organization concerned with establishing interoperability for learning systems and learning content * Indian Medical Service, a military medical service in British… …   Wikipedia

  • IMS — Die Abkürzung IMS steht für: in der Informatik: IMS Content Packaging, eine Spezifikation, die ein Datenformat für E Learning beschreibt IMTEK Mathematica Supplement, eine Sammlung von Numerik Paketen und Tutorials für Mathematica… …   Deutsch Wikipedia

  • IMS — abbr. comp. Information Managing System phys. Ion Mobility Spectrometer …   Dictionary of English abbreviation