Table 1. Mass spectrometer fragmentation pattern of nucleoside bases and formamide with their computed correction factor.
| m/z | G | A | T | U | C | F |
|---|---|---|---|---|---|---|
| 151 | 100 | — | — | — | — | — |
| 135 | 5 | 100 | — | — | — | — |
| 126 | — | — | 100 | — | — | — |
| 112 | — | — | — | 100 | — | — |
| 111 | — | — | — | — | 100 | — |
| 110 | 20 | — | — | — | — | — |
| 109 | 20 | — | — | — | — | — |
| 108 | — | 26 | — | — | — | — |
| 83 | — | — | 12 | — | 15 | — |
| 81 | 7 | — | — | — | — | — |
| 69 | 7 | — | — | 65 | 20 | — |
| 55 | — | 80 | — | — | — | |
| 54 | 17 | 11 | — | — | — | — |
| 45 | — | — | — | — | — | 100 |
| 43 | 30 | — | — | — | — | 11 |
| 29 | — | — | — | — | — | 34 |
| 17 | — | — | — | — | — | 32 |
| CF | 4.5 | 3.7 | 3.6 | 3.3 | 2.7 | 1.6 |
Patterns of nucleoside bases are from the National Institute of Standards and Technology. CF, mass spectrometer correction factor based on the parent ion. A, adenine; C, cytosine; G, guanine; T, thymine; U, uracil; F, formamide. Boldface type indicates molecular weight.