Review Article
Electrospray Ionization Mass Spectrometry: A Technique to Access the Information beyond the Molecular Weight of the Analyte
Table 1
Typical redox reactions of the solvents expected to occur in the electrospray emitter and their corresponding standard potentials.
| Solvent systems | Positive-ion mode | Negative-ion mode | Oxidation reactions | E 0 (V) | Reduction reactions | E 0 (V) |
| Water | 2H2O = O2 + 4H+ + 2e− | 1.23 | 2H2O + O2 + 4e− = 4OH− | 0.40 | 2H2O = H2O2 + 2H+ + 2e− | 1.77 | H2O + + e− = H + OH− | 0.20 | H2O = HO* + H+ + e− | 2.72 | H2O + H + e− = HO* + 2OH− | 0.18 | | | 2H2O + 2e− = H2 + 2OH− | 0.07 | | | 2H2O + O2 + 2e− = H2O2 + 2OH− | −0.13 | | | H2O + O2 + 2e− = H + OH− | −0.83 |
| Methanol | CH3OH = HCHO + 2H+ + 2e− | 0.23 | CH3OH + H2O + 2e− = CH4 + 2OH− | −0.25 | CH3OH + H2O = HCOOH + 4H+ + 4e− | 0.10 | CH3OH + 2H+ + 2e− = CH4 + H2O | 0.58 | HCOOH = CO2 + 2H+ + 2e− | −0.20 | | |
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