retention time
What retention time means in Chemistry A-Level, as defined for AQA, OCR.
Definitions of retention time
Exam boards and our study guides word this term in slightly different ways. Learn the version your board uses.
Check what you remember
Read the wording for your board, then hide it and explain retention time in your own words. Rough notes are fine. This is a self-check, with no mark or grade.
Reference: AQA
The time at which each component left the column, which on its own is not enough to identify a component because two different compounds can share it.
The time a component spends in the column before it emerges and is detected, measured from injection to the peak maximum on the chromatogram.
The time a component takes to leave a gas chromatography column.
Topics that use retention time
- Chromatography (A-level only) (AQA A-Level)
- Chromatography and qualitative analysis (OCR A-Level)
Related terms
- 2,4-dinitrophenylhydrazone derivative
- Acidified dichromate(VI) and alcohols
- adsorption
- Adsorption and differential movement
- Adsorption and spot position
- Bromine water and alkenes
- Bromine water test for alkenes
- Carbon–halogen bond strength and reactivity
Using retention time in the exam
Check the command word and mark scheme for your exact question. After comparing your explanation with the reference, use the term in an answer on the linked topic. This practice does not predict an exam mark.
Practise Chemistry questions
Create a free account to answer exam-style questions on this topic and get feedback on your answers.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge