Electrospray mass spectrometry of borane salts: The electrospray needle as an electrochemical cell

Hop, Cornelis E. C. A.; Saulys, Dovas A.; Gaines, Donald F.

doi:10.1016/1044-0305(95)00478-v

Cited by 24 publications

(18 citation statements)

References 26 publications

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“…5, Table 3). There are reports in the literature of the electrospray needle acting as an electrochemical cell, 29 and it is possible that a similar phenomenon occurs with these adducted peptides. Once the adducted peptide is formed by electrophilic addition of the amino group of the peptide to the 1,4-naphthoquinone (Scheme 2, A), the electron-donating property of the amino group may make the original adduct unstable resulting in further oxidation to the corresponding quinone adduct (Scheme 2, B), similar to naphthoquinone-like 4-hydroxyequilenin and 4-hydroxyequilin glutathione conjugates.…”

Section: Structural Analysis Of Adducts Of Apomyoglobin With Naphthoqmentioning

confidence: 97%

Structural analysis of naphthoquinone protein adducts with liquid chromatography/tandem mass spectrometry and the scoring algorithm for spectral analysis (SALSA)

Zhang

Bartels

2004

Rapid Comm Mass Spectrometry

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The relative reactivities of various naphthoquinone isomers (1,4-, 1,2- and 2-methyl-1,4-naphthoquinone) to two test proteins, apomyoglobin and human hemoglobin, were evaluated via liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS). The structural characterization of the resulting adducts was also obtained by LC/ESI-MS analysis of the intact proteins. The reactive sites of apomyoglobin and human hemoglobin with 1,4-naphthoquinone and 1,2-naphthoquinone were also identified through characterization of adducted tryptic peptides by use of high-pressure liquid chromatography/electrospray ionization with tandem mass spectrometry (HPLC/ESI-MS/MS), TurboSEQUEST, and the scoring algorithm for spectral analysis (SALSA). Four adducted peptides, which were formed by nucleophilic addition of a lysine amino acid residue to 1,4-naphthoquinone, were also identified, as was an adducted peptide from incubation of 1,2-naphthoquinone with apomyoglobin. In the case of incubation of human hemoglobin with the two naphthoquinones, two adducted peptides were identified from the N-terminal valine modification of the alpha and beta chains of human hemoglobin. The adducted protein formation may imply that naphthalene produces its in vivo toxicity through 1,2- and 1,4-naphthoquinone metabolites reacting with biomolecular proteins.

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Section: Structural Analysis Of Adducts Of Apomyoglobin With Naphthoqmentioning

confidence: 97%

Structural analysis of naphthoquinone protein adducts with liquid chromatography/tandem mass spectrometry and the scoring algorithm for spectral analysis (SALSA)

Zhang

Bartels

2004

Rapid Comm Mass Spectrometry

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“…Hop and co-workers [57][58][59][60] reported the ESI-MS observation on a host of boron and rhenium complexes. In CH 3 CN solutions, neutral rhenium complexes such as (Ind)Re(CO) 3 (Ind = indenyl) and (Cp)Re(CO) 3 (Cp = cyclopentadienyl) gave rise to [Re(CO) 3 (CH 3 CN) 3 ] ions.…”

Section: Organometallic and Inorganic Chemistrymentioning

confidence: 98%

“…For example, reaction of C 60 with ozone in toluene afforded the formation of several C 60 oxides. Negative ion ESI-MS revealed signals corresponding to C 60 O n (n = 1, 2, 3, 4, 5) in which two of the C 60 O 2 isomers were structurally identified. 203 As mentioned earlier, C 60 can readily undergo reduction to yield its radical anion.…”

Section: Fullerenesmentioning

confidence: 98%

“…[194][195][196][197][198] Fullerenes readily yielded negative ion (e.g. C 60 can be reduced at a relatively positive potential to its radical anion) ESI mass spectra using toluene, benzene or their equimolar binary solution with methanol or acetonitrile. 194,195 However, direct observation of cationic species was not trivial.…”

Section: Fullerenesmentioning

confidence: 99%

“…61 Presumably, the interaction of Na with the bipyridine moiety (in neat methanol) resulted in signals corresponding to [ exhibited reactivity with methanol during the ESI process while they were inert in acetonitrile solutions. 60 Although in rare cases it is conceivable that the inherent electrolytic process of ESI renders changes in the bulk solution pH, solvent reactivity and oxidation state of the analyte of interest. 62,63 Other air-sensitive organoboron ligands such as diazaborolidine complexes have been successfully analyzed by ESI-MS in anhydrous THF.…”

Section: Organometallic and Inorganic Chemistrymentioning

confidence: 99%

See 2 more Smart Citations

Unravelling seemingly complex chemistry of reactions using electrospray ionization mass spectrometry

Bakhtiar

Hop

1999

J. Phys. Org. Chem.

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Since its discovery, electrospray ionization mass spectrometry (ESI-MS) has provided valuable information on structurally specific biomolecular interactions, including DNA-drug, enzyme-inhibitor, DNAprotein and protein-protein interactions. In addition, this technique has emerged as a powerful tool in probing the structural modification of large molecules. However, ESI-MS has been underutilized in analysis and mechanistic studies involving small molecules. Here, a brief overview is presented to familiarize non-specialists with ESI-MS applications in analysis and mechanistic studies of small molecules. For more advanced applications (e.g. biopolymers) or detailed analytical descriptions of the ionization processes and the equipment, readers are referred to a number of excellent reviews and books.

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Electrolytic deposition of metals on to the high-voltage contact in an electrospray emitter: implications for gas-phase ion formation

Berkel

2000

J. Mass Spectrom.

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The electrospray ion source is an electrolytic flow cell. Electrolytic reactions in the electrospray emitter maintain the production of charged droplets by this ion source that contain an excess of ions of one polarity. These redox reactions necessarily change the composition of the solution that initially enters the emitter. As a result, the ions ultimately observed in the gas phase by electrospray mass spectrometry (ESMS) may be substantially influenced by both the nature and extent of these electrochemical reactions. It is demonstrated in this paper that Ag(+), Cu(2+) and Hg(2+) ions in solution can be electrolytically reduced and deposited as the respective metals on to the surface of the high-voltage contact in the electrospray emitter in negative ion mode electrospray. The deposited metals are shown to be liberated from the surface by switching the electrospray high-voltage polarity to operate in the positive ion mode. The deposited metals are oxidized in positive ion mode, releasing the metal ions back into solution where they are detected in the electrospray mass spectrum. In a semi-quantitative analysis, it was found that up to 50% of the Ag(+) in a 2.5 microM solution was deposited on the high-voltage contact of the emitter as the solution flowed through the emitter. Deposition of Cu(2+) and Hg(2+) was less efficient. These data illustrate that in the analysis of metals by ESMS, one must be aware that both the concentration and form of the metals may be altered by electrochemical processes in the emitter. Hence reduction or oxidation of metals in the electrospray emitter, which may remove ions from solution, or change metal valence, would be expected to impact both quantitative metal determinations and metal speciation attempts using ESMS.

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Electrospray mass spectrometry of borane salts: The electrospray needle as an electrochemical cell

Cited by 24 publications

References 26 publications

Structural analysis of naphthoquinone protein adducts with liquid chromatography/tandem mass spectrometry and the scoring algorithm for spectral analysis (SALSA)

Structural analysis of naphthoquinone protein adducts with liquid chromatography/tandem mass spectrometry and the scoring algorithm for spectral analysis (SALSA)

Unravelling seemingly complex chemistry of reactions using electrospray ionization mass spectrometry

Electrolytic deposition of metals on to the high-voltage contact in an electrospray emitter: implications for gas-phase ion formation

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