Table 3. Mass Accuracy Information of Example Peptides for Linear Ion Trap and Orbitrap.
| linear ion trap |
Orbitrap |
||||||
|---|---|---|---|---|---|---|---|
| peptide | modifications | obsd m/z | theor m/z | error Δppm | obsd m/z | theor m/z | error Δppm |
| H3 18–26 | none | 577.93 | 577.85 | 138 | 577.849 | 577.849 | 0.00 |
| K23me1 | 584.90 | 584.86 | 120 | 584.857 | 584.857 | 0.00 | |
| K18me1 | 584.93 | 584.86 | 120 | 584.857 | 584.857 | 0.00 | |
| K18ac or K23ac | 570.93 | 570.84 | 158 | 570.842 | 570.841 | 1.75 | |
| K18acK23ac | 563.93 | 563.83 | 177 | 563.832 | 563.833 | 1.18 | |
| H4 4–17 | none | 776.10 | 775.95 | 193 | 775.955 | 775.955 | 0.00 |
| 1 Ac | 769.02 | 768.95 | 91.0 | 768.948 | 768.947 | 1.30 | |
| 2 Ac | 762.02 | 761.94 | 105 | 761.934 | 761.939 | 6.56 | |
| 3 Ac | 754.97 | 754.93 | 53.0 | 754.926 | 754.931 | 6.62 | |
| 4 Ac | 748.02 | 747.92 | 134 | 747.924 | 747.922 | 2.67 | |
| average | 129 | average | 2.01 | ||||