Chemical Sciences: A Manual for CSIR-UGC National Eligibility Test for Lectureship and JRF/Reflectron

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Lens stack from a reflectron mass spectrometer. The metal plates carry the voltages and form the electric field that reflects ions.

A reflectron (also known as an ion mirror) is a type of time-of-flight mass spectrometer that uses a static electric field to reverse the direction of travel of the ions entering it. A reflectron improves mass resolution by assuring that ions of the same m/z but different kinetic energy arrive at the detector at the same time. The reflectron was invented by the Russian scientist Boris Aleksandrovich Mamyrin in 1973. [1][2]

Single Stage Reflectron[edit]

Schematic of a single-stage reflectron.

A single stage reflectron is composed of a single electric field region. The field can be linear or non-linear.

A curved-field reflectron is one in which the retarding field is non-linear and the voltages on the lens elements follow the equation of an arc of a circle according to R2 = V2 + x2, where x is the distance from the reflectron entrance, V is the voltage and R is a constant.[3][4]

A quadratic field reflectron is one in which the electric field varies with the square of the distance from the entrance and compensates for kinetic energy spread to all orders.[5]

Dual Stage Reflectron[edit]

Schematic of a dual-stage reflectron.

A dual-stage reflectron is composed of two electric field regions with the field strength in the first region significantly larger than in the second region so as to reduce the size of the device and to provide second-order kinetic energy focusing.[6]

Post Source Decay[edit]

Post source decay is a technique specific to reflectron time-of-flight mass spectrometers where product ions of metastable transitions or collision-induced dissociations generated in the drift tube prior to entering the reflectron are m/z separated to yield product ion spectra.[7]

References[edit]

  1. * Mamyrin, B. A.; Karataev, V. I.; Shmikk, D. V.; Zagulin, V. A. The mass-reflectron, a new nonmagnetic time-of-flight mass spectrometer with high resolution Sov. Phys. JETP, 1973, 37, 45.
  2. Mamyrin, Boris (2001-03-22), "Time-of-flight mass spectrometry (concepts, achievements, and prospects)", International Journal of Mass Spectrometry 206 (3): 251–266, doi:10.1016/S1387-3806(00)00392-4. 
  3. Cornish, Timothy J.; Cotter, RJ (1993), "A curved-field reflectron for improved energy focusing of product ions in time-of-flight mass spectrometry", Rapid Communications in Mass Spectrometry 7 (11): 1037, doi:10.1002/rcm.1290071114, PMID 8280914 
  4. Cotter, R.; Iltchenko, S; Wang, D (2005), "The curved-field reflectron: PSD and CID without scanning, stepping or lifting", International Journal of Mass Spectrometry 240: 169, doi:10.1016/j.ijms.2004.09.022 
  5. Flensburg, J.; Haid, D; Blomberg, J; Bielawski, J; Ivansson, D (2004), "Applications and performance of a MALDI-ToF mass spectrometer with quadratic field reflectron technology", Journal of Biochemical and Biophysical Methods 60 (3): 319, doi:10.1016/j.jbbm.2004.01.010, PMID 15345299 
  6. Wang, Tzyy-Ing; Chu, Chun-Wen; Hung, Hui-Ming; Kuo, Gen-Sen; Han, Chau-Chung (1994), "Design parameters of dual-stage ion reflectrons", Review of Scientific Instruments 65: 1585, doi:10.1063/1.1144896 
  7. Kaufmann, R.; Kirsch, D.; Spengler, B. (1994), "Sequenching of peptides in a time-of-flight mass spectrometer: evaluation of postsource decay following matrix-assisted laser desorption ionisation (MALDI)", International Journal of Mass Spectrometry and Ion Processes 131: 355, doi:10.1016/0168-1176(93)03876-N 

Bibliography[edit]

  • Cotter, Robert J. (1994), Time-of-flight mass spectrometry, Columbus, OH: American Chemical Society, ISBN 0-8412-3474-4