molecular ion


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molecular ion

[mə′lek·yə·lər ′ī‚än]
(organic chemistry)
An ion that results from the loss of an electron by an organic molecule following bombardment with high-energy electrons during mass spectrometry.
References in periodicals archive ?
The collision-induced dissociation (CID) spectrum of m/z 130, which corresponds to the protonated molecular ion of the racemic PA mixture, is shown in Fig.
In addition the design of the electrospray ion source can permit a molecular ion to undergo a process known as collisionally induced decomposition.
The EI-MS of 1 displayed a molecular ion peak at m/z 545 indicating the presence of odd number of nitrogen atom in 1.
For n-butyl-SA the major product ions from the M+1 molecular ion were obtained by the loss of 74 and 130 Da.
The sample readily fragments after EI, while CI often produces only a single, protonated, molecular ion.
Thus it showed the presence of the molecular ion peak at 291 and a number of fragments agree with the proposed structure (Scheme-1).
Second Part 1 new, high-speed and throughput of a triple quadrupole mass spectrometer (LCMS device) to obtain ESI and APCI ion source capable of quasi-molecular ions monitored, nuts - leEinyion transitions scan, neutral loss testing, precursor ions of the molecular ion identification.
This spectrum was acquired by transmitting the protonated molecular ion via [Q.sub.1] and scanning the second resolving quadrupole, [Q.sup.3], for products resulting from fragmentation in the collision cell.
The HR-EI-MS displayed molecular ion peak at m/z344.0873 corresponding to the molecular formula C18H16O7 with eleven double bond equivalence (DBE).
Both of these spectra were acquired by [Q.sub.1] transmission of the protonated molecular ion, m/z 231, and scanning the second resolving quadrupole ([Q.sub.3]) for products resulting from fragmentation in the collision cell.
Conversely, for homologous series of compounds IR spectra can be very similar, while mass spectra can provide definitive identification from molecular ion data.
The signals of the molecular ion (M) and of its [sup.13]C-containing fragments (F), chosen for M/M+1 or F/F+1 peak selective monitoring, show low intensity, and some other fragments of identical mass may produce interfering signals.

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