Utility of solution electrochemistry mass spectrometry for investigation the formation and detection of biologically important conjugates of acetaminophen
| Autor: | T.A. McRae, T.A. Getek, J.A. Hinson, Walter A. Korfmacher |
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| Rok vydání: | 1989 |
| Předmět: |
Chromatography
Chemical Phenomena Chemistry digestive oral and skin physiology Organic Chemistry Thermospray General Medicine Glutathione Electrochemistry Mass spectrometry Biochemistry Mass Spectrometry Analytical Chemistry Ion Coulometry chemistry.chemical_compound Oxidation-Reduction Chromatography High Pressure Liquid Acetaminophen Cysteine Conjugate |
| Zdroj: | Journal of Chromatography A. 474:245-256 |
| ISSN: | 0021-9673 |
| DOI: | 10.1016/s0021-9673(01)93919-6 |
| Popis: | On-line formation and detection of glutathione and cysteine conjugates of acetaminophen were accomplished by the interfacing of a coulometric electrochemical cell with a thermospray mass spectrometer in a flow-injection experiment using a liquid chromatographic pump. Formation of the conjugates occurred only after acetaminophen was oxidized electrochemically by a two-electron transfer to N-acetyl-p-benzoquinoneimine and reacted in a mixing tee with either glutathione or cysteine. The newly formed conjugate was detected by thermospray mass spectrometry by observing the [M + H]+ ion for the acetaminophen-glutathione conjugate at m/z 457, or the [M + H]+ ion for the acetaminophen cysteine conjugate at m/z 271. Both the glutathione and cysteine conjugates produced a common fragment ion at m/z 184. The on-line reaction of glutathione and electrochemically generated N-acetyl-p-benzoquinoneimine was monitored at varying pH. At pH 8.5 the ion intensity for the acetaminophen-glutathione conjugate was greater than at lower pH, indicating that lower proton concentration enhanced the reaction of glutathione with N-acetyl-p-benzoquinoneimine. This on-line electrochemical-thermospray mass spectrometric method demonstrated that acetaminophen conjugates may be formed and detected in the time frame of 1 s. |
| Databáze: | OpenAIRE |
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