6


A miniaturised ultra-FAIMS system (Owlstone Ltd) has been hyphenated to time-of- flight (Agilent 6230) and ion trap (Thermo LTQ) mass spectrometers in our lab at Loughborough and applied to the analysis of peptide and protein digests [12]. Using this chip-based planar device we have been able to the acquire data on


synthetic peptides and a tryptic digest of α-acid-glycoprotein. A pseudo-peptide mass fingerprint was generated by using the FAIMS to transmit only singly charged


species. This was then submitted to a Mascot search which returned α-acid- glycoprotein as the top hit with a statistically significant score of 61. The ultraFAIMS can also be used to preselect doubly charged species prior to tandem mass spectrometry, resulting in an enhancement in S/N ratio of an order of magnitude and allowing ions previously masked by the chemical background to be identified.


Conformor analysis has also been demonstrated using ultra-FAIMS. Figure 5 shows the CV scan from the doubly charged ion of bradykinin. The extracted ion trace for the [M+2H]+ ion shows distinct partially resolved conformers, demonstrating the potential of ultra-FAIMS for distinguishing between isobaric species on the basis of their gas phase conformation.


References 1. Buryakov, I.A., Krylov, E.V., Nazarov, E.G., Rasulev, U.K.,1993 “A new method of separation of multi-atomic ions by mobility at atmospheric pressure using a high- frequency amplitude-asymmetric strong electric field.” International Journal of Mass Spectrometry and Ion Processes, Vol. 128, pp. 143-148


2. Purves, R. W., R. Guevremont, Day, S., Pipich, C.W., Matyjaszczyk, M.S.,1998 “Mass spectrometric characterization of a high-field asymmetric waveform ion mobility spectrometer” Review of Scientific Instruments. Vol. 69, pp.4094-4105


3. Shvartsburg, A.A., 2008 “Differential Mobility Spectrometry” CRC Press, 1st edition.


4. Kolakowski B.M, Mester Z. 2007 “Review of applications of high-field asymmetric waveform ion mobility spectrometry (FAIMS) and differential mobility spectrometry (DMS)“ Analyst, Vol. 132, pp.842-864


5. Shvartzburg A.A, Smith R.D, Wilks A, Koehl A, Ruiz-Alonso D, Boyle P. 2009, “Ultrafast Differential Ion Mobility Spectrometry at Extreme Electric Fields in Multichannel Microchips” Analytical Chemistry., Vol. 81, pp.6489-6495


6. O’Donnell R.M, Sun X.B, Harrington P.D.,2008 “Pharmaceutical applications of ion mobility spectrometry”, TRAC-Trends in Analytical Chemistry, Vol. 27, pp.44-53


7. McCooeye M, Mester Z, Ells B, Barnett DA, Purves RW, Guevremont R. 2002 “Quantitation of amphetamine, methamphetamine, and their methylenedioxy derivatives in urine by solid-phase microextraction coupled with electrospray ionization-high-field asymmetric waveform ion mobility spectrometry-mass spectrometry.” Analytical Chemistry Vol. 74, pp.3071-3075


Conclusions


Differential mobility separation can be used as an orthogonal technique to mass spectrometry for the analysis of small molecules. Thanks to its fast analysis times and high sensitivity, planar FAIMS can be used as a rugged standalone detector for use in the field and, when hyphenated to mass spectrometry, can be used to enhance selectivity, S/N ratios and limits of detection by reducing interference from background species.


FAIMS-MS analysis can be used to separate and quantify species such as isobaric and isomeric ions that cannot be resolved by MS alone. The development of new FAIMS systems designed specifically to be used in conjunction with mass spectrometry is continuing and new methods, such as ultra-FAIMS, are expected to play an increasingly important role in the future.


8. McCooeye M , M, Ding L, Gardner G.J, Fraser C.A, Lam J, Sturgeon R.E, Mester Z. 2003, “Separation and quantitation of the stereoisomers of ephedra alkaloids in natural health products using flow injection-electrospray ionization-high field asymmetric waveform ion mobility spectrometry-mass spectrometry.” Analytical. Chemistry., Vol. 75, pp.2538-2542


9. Mie, A.; Ray, A.; Axelsson, B. O.; Jornten-Karlsson, M.; Reimann, C. T. 2008 “Terbutaline enantiomer separation and quantification by complexation and field asymmetric ion mobility spectrometry-tandem mass spectrometry.” Analytical Chemistry, Vol.80, pp.4133-4140


10. Harry E.L, Bristow A.W.T, Wilson I.D, Barnett A, Ball G, Creaser C.S. 2009, “An enhanced metabonomic approach employing LC-FAIMS-MS to study the effects of age on the profile of endogenous metabolites in rat urine” Proceedings of the 2009 Analytical Research Forum, University of Kent, Canterbury


11. Purves R.W, Guevremont R.1999 “Electrospray ionization high-field asymmetric waveform ion mobility spectrometry-mass spectrometry” Analytical Chemistry. Vol.71, pp.2346-2357


12. Brown, L.J.; D. E. Toutoungi, D.E.; Devenport, N.A.; Reynolds, J.C.; Kaur-Atwal, G.; Boyle, P.; Creaser, C.S. 2010 “Miniaturised Ultra High Field Asymmetric Waveform Ion Mobility Spectrometry Combined with Mass Spectrometry for Peptide Analysis” Analytical Chemistry, Vol. 82, pp.9827-9834


Interested in publishing a Technical Article?


Contact Gwyneth on +44 (0)1727 855574


or email: gwyneth@intlabmate.com


College Spectrophotometer Investment Oberlin College continues its emphasis on


the highest level of education with its investment in top research grade spectrophotometers for its chemistry and biochemistry teaching laboratories.


Oberlin chose the Biochrom WPA Biowave II UV/Visible Spectrophotometers to teach the nation’s next generation of scientists.


These Biochrom spectrophotometers enable the students to engage in the most current molecular biology, life science, and chemistry protocols, combining life science methods with rapid scanning, kinetics and concentration capabilities.


Along with the highest functionality these instruments are durable, low maintenance and designed for high usage.


Oberlin College in Oberlin, Ohio is one of the United States’ premier liberal arts and sciences colleges. The Oberlin College Chemistry and Biochemistry department prides itself in offering flexible and interdisciplinary coursework with faculty-student research, which ranges from bioorganic chemistry to atmospheric chemistry, photochemistry to catalysis research, materials chemistry to peptide structure, and cancer biochemistry to natural products research.


Circle no. 12 Circle no. 11


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