Table 1.
The specific mass spectrometric settings for each substance and their corresponding internal standard. MRM transitions with protonated molecule and monitored fragments in positive mode. Retention time, cone voltage, and collision energy for each analyte
| Substance | ESI mode | Retention time (min) | MRM transitions (m/z) Quantifier/qualifier |
Cone voltage (V) | Collision energy (eV) |
|---|---|---|---|---|---|
| dTG | + | 2.28 |
283.97>150.61 283.97>167.72 |
22 22 |
34 10 |
| dTG-IS | + | 1.72 |
283.00>143.94 283.00>161.96 |
4 4 |
34 10 |
| dC | + | 0.9 |
227.97>94.28 227.97>111.54 |
2 2 |
36 10 |
| dC-IS | + | 0.9 | 230.97>114.54 | 8 | 12 |
Abbreviations: dTG, 2′-deoxythioguanosine; dTG-IS, 2′-deoxyguanosine-13C1015N5; dC, 2′ deoxycytidine; dC-IS, 2′-deoxycytidine-13C15N2