Energy-dependent collision-induced dissociation of lithiated polytetrahydrofuran: Effect of the size on the fragmentation properties

Abstract

The fragmentation properties of singly and doubly lithiated polytetrahydrofuran (PTHF) were studied using energy-dependent collision-induced dissociation. The product ion spectrum of [PTHF ϩ Li] ϩ 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 C 4 H 9 O ϩ and C 4 H 7 ϩ were identified in the MS/MS spectra. The MS/MS of the doubly lithiated PTHF () 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 ϩ -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 ϩ Li] ϩ and [PTHF ϩ 2Li] 2ϩ were also interpreted using the survival yield method. It was found that the collision energy/voltage necessary to obtain 50% fragmentation (CV 50 ) was dependent linearly on the number of the repeat units, i.e., on the size, or the number of degrees of freedom

Tandem Mass Spectrometric Analysis of a Mixture of Isobars Using the Survival Yield Technique

“…A 5:1 ratio was found more suitable for illustrative purposes; a detailed analysis of this aspect is presented in the following section discussing quantitative information. For convenience, and without loss of information, these spectra are presented on the same mass range going from m/z 1350 up to m/z 1700; spectrum for [PLA 23 and is shifted from the aforementioned series by −18 Th (for detailed discussions of fragmentation mechanisms and MS/MS spectra interpretations, one may refer to recent publications [13,14]). However, in the case of a mixture of PTMEG samples with PLA, which we may refer to as contamination throughout the discussion, visual inspection is not sufficient to distinguish between fragment ions (spectrum b in Figure 1).…”

Gas-Phase Lithium Cation Basicity: Revisiting the High Basicity Range by Experiment and Theory

“…Analytical mass spectrometry makes use of the formation of gas-phase adducts with metal cations (a process often called cationization), and Li + has been extensively examined in this regard. Lithium adduct generation occurs easily, starting in general from a condensed phase, when polar functional groups are present in analytes [21][22][23][24][25]. Another specific tool, which emerged from the observation of direct gas-phase cationization by Li + , the so-called ion attachment mass spectrometry (IAMS) [26][27][28][29], makes use of the attachment of the cation to neutral species in the gas phase.…”

Gas Phase Chemistry of Li+with Amides: the Observation of LiOH Loss in Mass Spectrometry

“…On the other hand, the mass spectrometric fragmentations of metal cationized, especially lithiated biomolecules, have attracted much attention because of the desire to measure intrinsic metal ion affinity and identify the binding sites [14,15], and because the interesting dissociation pathways exhibited by these compounds are usually different from the protonated and deprotonated analogues [16,17]. Recently, the fragmentation behaviors of lithiated species have been reported for peptides, fatty acids, phospholipids, polytetrahydrofuran, cardiolipins, thioesters, cholesteryl esters, and disaccharides [18][19][20][21][22][23][24][25][26].…”