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001-es BibID:	BIBFORM030616
Első szerző:	Kuki Ákos (villamosmérnök)
Cím:	A simple method to estimate relative stabilities of polyethers cationized by alkali metal ions / Ákos Kuki, Lajos Nagy, Ghazaleh Shemirani, Antony Memboeuf, László Drahos, Károly Vékey, Miklós Zsuga, Sándor Kéki
Dátum:	2012
ISSN:	0951-4198
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban Fizikai-, Számítás- és Anyagtudomány
Megjelenés:	Rapid Communications In Mass Spectrometry. - 26 : 3 (2012), p. 304-308. -
További szerzők:	Nagy Lajos (1979-) (vegyész) Shemirani, Ghazaleh (1983-) (vegyész) Memboeuf, Antony Drahos László Vékey Károly Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:	TÁMOP-4.2.1/B-09/1/KONV-2010-0007 TÁMOP Kémiai anyagtudományi csoport
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001-es BibID:	BIBFORM016383
Első szerző:	Kuki Ákos (villamosmérnök)
Cím:	Energy-dependent collision-induced dissociation of lithiated polytetrahydrofuran : Effect of the size on the fragmentation properties / Ákos Kuki, Lajos Nagy, Antony Memboeuf, László Drahos, Károly Vékey, Miklós Zsuga, Sándor Kéki
Dátum:	2010
ISSN:	1044-0305
Megjegyzések:	The fragmentation properties of singly and doubly lithiated polytetrahydrofuran (PTHF) were studied using energy-dependent collision-induced dissociation. The product ion spectrum of [PTHF+Li]+ showed the formation of three different series corresponding to product ions with hydroxyl, aldehyde and vinyl end-groups. Interestingly, besides these series, two additional, non-lithiated product ions C4H9O+ and C4H7+ were identified in the MS/MS spectra. The MS/MS of the doubly lithiated PTHF ([PTHF+2Li]2+) with a number of repeat units ranging from 8 to 27 showed the formation of product ions similar to those of the singly lithiated series, however, doubly lithiated product ions and product ions formed by the loss of one Li+-ion from the precursor ion also appeared with significant abundances. Analysis of the breakdown curves for the singly and doubly charged PTHF indicated that the series A ions are formed most probably together with the series B ions, while members of the series C ions appeared at significantly higher collision energies. The fragmentation properties of [PTHF+Li]+ and [PTHF+2Li]2+ were also interpreted using the survival yield method. It was found that the collision energy/voltage necessary to obtain 50% fragmentation (CV50) was dependent linearly on the number of the repeat units, i.e., on the size, or the number of degrees of freedom (DOF).
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Journal Of The American Society For Mass Spectrometry. - 21 : 10 (2010), p. 1753-1761. -
További szerzők:	Nagy Lajos (1979-) (vegyész) Memboeuf, Antony Drahos László Vékey Károly Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
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001-es BibID:	BIBFORM018657
035-os BibID:	(WoS)000275379300019 (Scopus)77949790049
Első szerző:	Memboeuf, Antony
Cím:	Size Effect on Fragmentation in Tandem Mass Spectrometry / Antony Memboeuf, Andreas Nasioudis, Sergio Indelicato, Ferenc Pollreisz, Ákos Kuki, Sándor Kéki, Oscar F. van den Brink, Károly Vékey, László Drahos
Dátum:	2010
ISSN:	0003-2700
Megjegyzések:	The collision energy or collision voltage necessary to obtain 50% fragmentation (characteristic collision energy/voltage, CCE or CCV) has been systematically determined for different types of molecules [poly(ethylene glycols) (PEG), poly(tetrahydrofuran) (PTHF), and peptides] over a wide mass (degrees of freedom) range. In the case of lithium-cationized PEGs a clear linear correlation (R(2) > 0.996) has been found between CCE and precursor ion mass on various instrument types up to 4.5 kDa. A similar linear correlation was observed between CCV and the mass-to-charge ratio. For singly and multiply charged polymers studied under a variety of experimental conditions and on several instruments, all data were plotted together and showed correlation coefficient R(2) = 0.991. A prerequisite to observe such a good linear correlation is that the energy and entropy of activation in a class of polymers is likely to remain constant. When compounds of different structure are compared, the CCV will depend not only on the molecular mass but the activation energy and entropy as well. This finding has both theoretical and practical importance. From a theoretical point of view it suggests fast energy randomization up to at least 4.5 kDa so that statistical rate theories are applicable in this range. These results also suggest an easy method for instrument tuning for high-throughput structural characterization through tandem MS: after a standard compound is measured, the optimum excitation voltage is in a simple proportion with the mass of any structurally similar analyte at constant experimental conditions.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Surface-induced dissiciation Protonated leucine-enkephalin Electron-capture dissociation Polyethylene-glycol Internal energy Collisional activation Gas-phase Covalent attachment Nonergodic process Small peptides
Megjelenés:	Analytical Chemistry. - 82 : 6 (2010), p. 2294-2302. -
További szerzők:	Nasioudis, Andreas Indelicato, Sergio Pollreisz Ferenc Kuki Ákos (1966-) (villamosmérnök) Kéki Sándor (1964-) (polimer kémikus) Brink, Oscar F. van den Vékey Károly Drahos László
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