Mass spectrometry: difference between revisions
Diff·revision 5 → 6·23:57, 7 Aug 2024
Difference between revision 5 and revision 6 of Mass spectrometry. 2 lines changed; the page grew by 341 bytes.
| Revision 5 — 15:52, 23 Jul 2024 DiluentDiya (talk) add the equilibration time to the gradient description 2,090 bytes ±0 | Revision 6 — 23:57, 7 Aug 2024 TFA_Counterion (talk) add the figure for the chromatogram and caption its axes 2,431 bytes +341 | ||
|---|---|---|---|
| 15 | Mass analysers differ in resolution and in mass accuracy. A quadrupole gives unit resolution and is adequate for confirming a mass to within a dalton; time-of-flight and orbital-trap analysers give sufficient resolution to determine a mass to a few parts per million, which distinguishes species a quadrupole cannot. | 15 | Mass analysers differ in resolution and in mass accuracy. A quadrupole gives unit resolution and is adequate for confirming a mass to within a dalton; time-of-flight and orbital-trap analysers give sufficient resolution to determine a mass to a few parts per million, which distinguishes species a quadrupole cannot. |
| 16 | 16 | ||
| + | 17 | The distinction matters for peptide work because the confounders are close in mass. [[Deamidation|Deamidation]] adds 0.984 Da, which unit resolution cannot resolve from the parent; oxidation adds 16 Da, which it can. A report stating an observed mass without stating the resolution of the instrument understates the ambiguity.{{r|usp1503}} | |
| + | 18 | ||
| 17 | == References == | 19 | == References == |
| 18 | {{reflist}} | 20 | {{reflist}} |