Desorption electrospray ionization

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Desorption electrospray ionization
Acronym DESI
Classification Mass spectrometry
Analytes Organic molecules
Biomolecules
Other Techniques
Related Electrospray ionization
Atmospheric pressure chemical ionization
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Desorption electrospray ionization (DESI) is a method for creating ions that can be used in mass spectrometry for chemical analysis. In DESI, an electrospray source creates charged droplets that are directed at a solid sample a few millimeters to a few centimeters away. The charged droplets pick up the sample through interaction with the surface and then form highly charged ions that can be sampled into a mass spectrometer.[1]

Contents

[edit] Related techniques

Several related techniques have been reported.[2] They are similar in what they accomplish (i.e., desorption and soft ionization of molecules on a surface), but are mostly quite different in mechanism.

[edit] Chemical ionization

See also: chemical ionization

Desorption atmospheric pressure chemical ionization (DAPCI) uses a flow of solvent vapor and a corona discharge to affect ionization.[3] With atmospheric solids analysis probe (ASAP), a jet of heated gas is directed at the sample surface and the desorbed species are ionized by corona discharge.[4]

[edit] Glow discharge

Main article: DART ion source

The direct analysis in real-time (DART) ion source uses a glow discharge to create excited-state neutrals and ions that are then directed against the sample surface.[5]

[edit] Sonic spray

Main article: sonic spray ionization

Desorption sonic spray ionization (DeSSI)[6] uses sonic spray ionization[7] to form the ions that are directed at the sample surface.

[edit] Laser assisted

Electrospray-assisted laser desorption/ionization (ELDI) relies on a laser to the desorption of material into the electrospray plume.[8] With matrix-assisted laser desorption electrospray ionization (MALDESI), a nitrogen laser is used to desorb material into the electrospray.[9] MALDESI has been used with MALDI matrix materials. Laser ablation electrospray ionization (LAESI) uses an infrared laser for ablation of the sample material.[10] Desorption atmospheric pressure photoionization (DAPPI) is not an electrospray technique, but uses a jet of heated solvent for desorption and ultraviolet light for photoionization.[11]

[edit] References

  1. ^ Takáts Z, Wiseman JM, Cooks RG (2005). "Ambient mass spectrometry using desorption electrospray ionization (DESI): instrumentation, mechanisms and applications in forensics, chemistry, and biology". Journal of mass spectrometry : JMS 40 (10): 1261–75. doi:10.1002/jms.922. PMID 16237663. 
  2. ^ Cooks RG, Ouyang Z, Takats Z, Wiseman JM (2006). "Detection Technologies. Ambient mass spectrometry". Science 311 (5767): 1566–70. doi:10.1126/science.1119426. PMID 16543450. 
  3. ^ Takáts Z, Cotte-Rodriguez I, Talaty N, Chen H, Cooks RG (2005). "Direct, trace level detection of explosives on ambient surfaces by desorption electrospray ionization mass spectrometry". Chem. Commun. (Camb.) (15): 1950–2. doi:10.1039/b418697d. PMID 15834468. 
  4. ^ McEwen CN, McKay RG, Larsen BS (2005). "Analysis of solids, liquids, and biological tissues using solids probe introduction at atmospheric pressure on commercial LC/MS instruments". Anal. Chem. 77 (23): 7826–31. doi:10.1021/ac051470k. PMID 16316194. 
  5. ^ Cody RB, Laramée JA, Durst HD (2005). "Versatile new ion source for the analysis of materials in open air under ambient conditions". Anal. Chem. 77 (8): 2297–302. doi:10.1021/ac050162j. PMID 15828760. 
  6. ^ Haddad R, Sparrapan R, Eberlin MN (2006). "Desorption sonic spray ionization for (high) voltage-free ambient mass spectrometry". Rapid Commun. Mass Spectrom. 20 (19): 2901–5. doi:10.1002/rcm.2680. PMID 16941547. 
  7. ^ Hirabayashi A, Sakairi M, Koizumi H (1995). "Sonic spray mass spectrometry". Anal. Chem. 67 (17): 2878–82. PMID 8779414. 
  8. ^ Shiea J, Huang MZ, Hsu HJ, Lee CY, Yuan CH, Beech I, Sunner J (2005). "Electrospray-assisted laser desorption/ionization mass spectrometry for direct ambient analysis of solids". Rapid Commun. Mass Spectrom. 19 (24): 3701–4. doi:10.1002/rcm.2243. PMID 16299699. 
  9. ^ Sampson JS, Hawkridge AM, Muddiman DC (2006). "Generation and detection of multiply-charged peptides and proteins by matrix-assisted laser desorption electrospray ionization (MALDESI) Fourier transform ion cyclotron resonance mass spectrometry". J. Am. Soc. Mass Spectrom. 17 (12): 1712–6. doi:10.1016/j.jasms.2006.08.003. PMID 16952462. 
  10. ^ Nemes P, Vertes A (2007). "Laser Ablation Electrospray Ionization for Atmospheric Pressure, in Vivo, and Imaging Mass Spectrometry". doi:10.1021/ac071181r. PMID 17900146. 
  11. ^ Haapala M, Pól J, Saarela V, et al (2007). "Desorption Atmospheric Pressure Photoionization" 79 (20): 7867–7872. doi:10.1021/ac071152g. PMID 17803282. 

[edit] External links