Mass spectrometry: difference between revisions
Diff·revision 1 → 2·19:05, 30 Jun 2024
Difference between revision 1 and revision 2 of Mass spectrometry. 5 lines changed; the page grew by 732 bytes.
| Revision 1 — 02:39, 30 Jun 2024 ImportRecordIna (talk) start article on the analytical method 1,358 bytes +1,358 | Revision 2 — 19:05, 30 Jun 2024 ShortageShona (talk) close an unbalanced quotation mark 2,090 bytes +732 | ||
|---|---|---|---|
| 10 | A purity determination by [[High-performance liquid chromatography|chromatography]] establishes that one species dominates a sample; it does not establish which species. These are separate questions and require separate determinations. A [[Certificate of analysis|certificate]] reporting purity but no identity leaves the more fundamental of the two unanswered.{{r|usp1503}} | 10 | A purity determination by [[High-performance liquid chromatography|chromatography]] establishes that one species dominates a sample; it does not establish which species. These are separate questions and require separate determinations. A [[Certificate of analysis|certificate]] reporting purity but no identity leaves the more fundamental of the two unanswered.{{r|usp1503}} |
| 11 | 11 | ||
| + | 12 | == Ionisation and mass analysis == | |
| + | 13 | Electrospray disperses a solution into charged droplets in an electric field; solvent evaporates and ions are released into the gas phase. It is a soft technique — the molecule survives largely intact — which is why it suits peptides and proteins. Matrix-assisted laser desorption is the other common soft method and tends to produce singly charged ions.{{r|aebersold2003}} | |
| + | 14 | ||
| + | 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 | ||
| 12 | == References == | 17 | == References == |
| 13 | {{reflist}} | 18 | {{reflist}} |