Negative‐ion electrospray mass spectra of carbon dioxide‐protected <i>N</i>‐heterocyclic anions

Gross, Jürgen H.; Eckert, Anke K.; Siebert, Walter

doi:10.1002/jms.302

Cited by 10 publications

(3 citation statements)

References 10 publications

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“…The accurate mass measurements confirmed the composition of the fragment of interest at m / z 272.0797 for 4a (C 14 H 12 N 2 O 4 +• , − 0.4 ppm) and at m / z 264.1025 for 4c (C 17 H 14 NO 2 + , 1.1 ppm). Besides the dominant fragmentations discussed above, an interesting alternative fragmentation pathway occurs for all the studied compounds 4a – e which could be connected with the cleavage of the NC carbamate bond22, 23 to give the [M − 59] + ion (Table 1). The elemental compositions of these ions were also confirmed using accurate mass measurements, which afforded relative errors within the range − 0.4 to 1.6 ppm.…”

Section: Resultsmentioning

confidence: 94%

Unimolecular rearrangements of ketene‐O,O‐acetals and fragmentations occurring in the gas phase

et al. 2011

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Gas phase skeletal rearrangements of regioisomeric 3-cyano-2-methoxy-3a-alkylfuro[2,3-b]- and [3,2-b]indoles were evidenced by product ions [M-32](+•), consistent with loss of methanol, on electron ionization in their mass spectra. The rearranged products occurring in gas phase were demonstrated to have elemental composition and fragmentation properties identical to those of authentic samples of 2-indolyl cyanomalonates. Isotopic labeling experiments support the formation mechanism of the [M-32](+•) ion. Additional thermal gas-phase reaction products were characterized by comparison with an authentic sample.

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Section: Resultsmentioning

confidence: 94%

Unimolecular rearrangements of ketene‐O,O‐acetals and fragmentations occurring in the gas phase

et al. 2011

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“…Furthermore, Fig. 3 shows the effect of tube lens voltage in the intensity of the base peak.This voltage value is compound dependent and an excessive voltage would produce the in-source CID fragmentation [23]. The highest ion intensity for chlorophylls was achieved at 140 V, while for carotenoids maximum responses were obtained at 90 V. Moreover, these compounds experimented a significant in-source CID fragmentation above this tube lens offset voltage that caused the decrease in the protonated molecule ion intensity.…”

Section: Liquid Chromatography-mass Spectrometrymentioning

confidence: 99%

Simultaneous analysis of natural pigments and E-141i in olive oils by liquid chromatography–tandem mass spectrometry

Arrizabalaga-Larrañaga

Rodríguez

Sala

et al. 2019

Anal Bioanal Chem

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This work describes the development of an ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the determination of carotenoids (ß-carotene, lutein, ß-criptoxanthin, neoxanthin, violaxanthin) and chlorophylls, as well as their related compounds (chlorophyll A and B, pheophytin A and B and the banned dyes Cu-pyropheophytin A, Cu-pheophytin A and B) in olive oils. For this purpose, the feasibility of electrospray (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) for the ionization of these compounds was evaluated and compared. Tandem mass spectrometry (MS/MS) fragmentation was discussed for each family of compounds and the most characteristic and abundant product ions were selected to propose a selective and sensitive UHPLC-MS/MS method. The best results were obtained using APCI and APPI, while ESI provided the worst signal-to-noise ratio (S/N) for all compounds. For the analysis of olive oils, a simple solid phase extraction (SPE) with silica cartridges was applied before the determination by UHPLC-MS/MS (APCI and APPI) in multiple reaction monitoring (MRM) mode. Method quality parameters were stablished and the results demonstrate the good performance of the new methods, providing low limits of detection (0.004 -0.9 mg L-1), high extraction efficiencies (62 − 95%) and low matrix effects (<25%). The developed UHPLC-API-MS/MS (APCI and APPI) methods were applied to the analysis of olive oil samples and ß-carotene, pheophytin A, pheophytin B and lutein were detected and quantified in all of them at concentrations ranging from 0.1 to 9.5 mg L-1.

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“…However, such an approach obviously counteracts the intended transfer of cold, i.e., vibrationally non-exited ions, as it may induce fragmentation. 53 Therefore, selection of an ion for use as a precursor in tandem mass spectrometry (cf. below) generally presents the best way of studying an ion of defined solvation state.…”

Section: Cold-spray-ionizationmentioning

confidence: 99%

ESI and tandem MS for mechanistic studies with high-valent transition metal species

et al. 2022

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Negative‐ion electrospray mass spectra of carbon dioxide‐protected N‐heterocyclic anions

Cited by 10 publications

References 10 publications

Unimolecular rearrangements of ketene‐O,O‐acetals and fragmentations occurring in the gas phase

Unimolecular rearrangements of ketene‐O,O‐acetals and fragmentations occurring in the gas phase

Simultaneous analysis of natural pigments and E-141i in olive oils by liquid chromatography–tandem mass spectrometry

ESI and tandem MS for mechanistic studies with high-valent transition metal species

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