# A sports drink manufacturer wants to check that a new batch of drink contains the correct mixture of compounds. A sample of the drink is analysed using gas chromatography–mass spectrometry (GC-MS). Describe how GC-MS works and explain why it is particularly useful for analysing the sports drink sample.

> Eduqas A-Level Chemistry — 2.8 Instrumental analysis · Describe and Explain · 5 marks

## Mark scheme (5 marks)

1. The sample is vaporised and carried through a column by a carrier gas
2. Different compounds travel through the column at different speeds / have different retention times
3. The mass spectrometer identifies each separated compound by its mass spectrum / molecular mass
4. GC-MS can detect/identify very small amounts (traces) of compounds / is very sensitive
5. GC-MS can separate and identify multiple compounds at the same time / in a mixture, making it suitable for a complex sample like a sports drink

## Key terms

- [gas chromatography](https://www.gradenine.co.uk/glossary/gas-chromatography)
- [mass spectrometry](https://www.gradenine.co.uk/glossary/mass-spectrometry)

## Related

- [Revision notes for Eduqas A-Level Chemistry](https://www.gradenine.co.uk/learn)
- [How to answer "Describe and Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/a-sports-drink-manufacturer-wants-to-36c6a7c3) · Published by Druglandscape Ltd.