Terms beginning with E
5 of 238 glossary terms.
- Electrospray ionisation (ESI)
- Producing gas-phase ions from solution by applying a high potential to a fine spray. Multiply charges large molecules and is compatible with LC.
- Elemental impurity
- Trace metal contamination, controlled by ICH Q3D. Palladium, copper, nickel and chromium are the relevant risks in peptide synthesis. Not reported anywhere in this index.
- Epimerisation
- Inversion of a single stereocentre during synthesis, typically during carboxyl activation. Produces a diastereomer.
- Endotoxin unit (EU)
- The activity unit for bacterial endotoxin, defined against a reference standard. Roughly 0.1–0.2 ng of E. coli LPS per EU.
- Expanded uncertainty (U)
- Standard uncertainty multiplied by a coverage factor, usually k = 2 for approximately 95 % confidence.
see also Adduct · Ion suppression
see also ICP-MS
see also Diastereomer · Racemisation
see also Bacterial endotoxin
see also Standard uncertainty (u)