Table 1. Key Fragment Ions (m/z) and Common Neutral Losses (Monoisotopic Mass) Employed for Selective Screening of Metabolites in the Mercapturic Acid Pathway (MAP) in Negative Ionization Mode.
| Conjugate | Fragment ion (m/z) | Common neutral loss (Da) |
|---|---|---|
| Glutathione (GSH) | C10H14N3O6 (272.08881) | C10H19N3O7S (325.09437) |
| C10H17N3O7 (291.10665) | ||
| C10H16N3O6 (274.10391) | ||
| C10H15N3O6 (273.09609) | ||
| C5H10N2O4 (162.06406) | ||
| C5H10N2O3 (146.06914) | ||
| Cysteinylglycine (cysgly) | C5H9N2O3S (177.03394) | C5H12N2O4S (196.05178) |
| C5H7N2O3 (143.04622) | C5H10N2O4 (162.06406) | |
| C5H8N2O3 (144.05349) | ||
| Cysteine (cys) | C5H4NO2S (141.99682) | C3H9NO5 (139.04807) |
| C3H5NO2 (87.03203) | ||
| N-acetyl-l-cysteine (Mercapturic acid; MA) | C5H6NO3 (128.03532) | C5H7NO3 (129.04259) |