title: Estimation of activation energy from the survival yields: fragmentation study of leucine enkephalin and polyethers by tandem mass spectrometry.
abstract: A simple collision model for multiple collisions occurring in quadrupole type mass spectrometers was derived and tested with leucine enkaphalin a common mass spectrometric standard with well-characterized properties. Implementation of the collision model and Rice-Ramsperger-Kassel-Marcus (RRKM) algorithm into a spreadsheet software allowed a good fitting of the calculated data to the experimental survival yield (SY) versus collision energy curve. In addition, fitting also ensured to estimate the efficiencies of the kinetic to internal energy conversion for Leucine enkephalin in quadrupole-time-of-flight and triple quadrupole instruments. It was observed that the experimental SY versus collision energy curves for the leucine enkephalin can be described by the Rice-Ramsperger-Kassel (RRK) formalism by reducing the total degrees of freedom (DOF) to about one-fifth. Furthermore, this collision model with the RRK formalism was used to estimate the critical energy (E(o)) of lithiated polyethers, including polyethylene glycol (PEG), polypropylene glycol (PPG), and polytetrahydrofurane (PTHF) with degrees of freedom similar to that of leucine enkephalin. Applying polyethers with similar DOF provided the elimination of the effect of DOF on the unimolecular reaction rate constant. The estimated value of E(o) for PEG showed a relatively good agreement with the value calculated by high-level quantum chemical calculations reported in the literature. Interestingly, it was also found that the E(o) values for the studied polyethers were similar.
authors: Department of Applied Chemistry, University of Debrecen, 4010, Debrecen, Hungary.
authors: Ákos
authors: Á
authors: Kuki
authors: Ghazaleh
authors: G
authors: Shemirani
authors: Lajos
authors: L
authors: Nagy
authors: Borbála
authors: B
authors: Antal
authors: Miklós
authors: M
authors: Zsuga
authors: Sándor
authors: S
authors: Kéki
mesh_terms: D000465:Algorithms; D002072:Butylene Glycols / Q000737:chemistry; D004743:Enkephalin, Leucine / Q000737:chemistry*; D008956:Models, Chemical; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011409:Propylene Glycols / Q000737:chemistry; D012984:Software; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013816:Thermodynamics
chemical_list: D002072:Butylene Glycols; D011108:Polymers; D011409:Propylene Glycols; C524501:poly(tetrahydrofuran); C012504:polypropylene glycol; D011092:Polyethylene Glycols; D004743:Enkephalin, Leucine
references: Mass Spectrom Rev. 2005 Jul-Aug;24(4):566-87
references: 15317019
references: J Biol Chem. 1977 Jun 10;252(11):3582-6
references: 16907
references: J Pharm Sci. 2003 Jul;92(7):1343-55
references: 12820139
references: Biomaterials. 2000 May;21(10):1021-9
references: 10768754
references: Mass Spectrom Rev. 2011 Mar-Apr;30(2):298-320
references: 20669325
references: J Am Soc Mass Spectrom. 2002 Jan;13(1):59-71
references: 11777200
references: J Biomater Sci Polym Ed. 2007;18(5):561-78
references: 17550659
references: Rapid Commun Mass Spectrom. 2010 Aug 30;24(16):2471-3
references: 20658687
references: J Mass Spectrom. 2001 Mar;36(3):237-63
references: 11312517
references: J Biomed Mater Res. 1998 Sep 15;41(4):633-48
references: 9697037