# A food scientist suspects that a batch of fruit juice has been adulterated with an unknown additive. Explain how gas chromatography-mass spectrometry (GC-MS) could be used to identify the unknown additive in the fruit juice sample.

> Edexcel A-Level Chemistry (9CH0) — Topic 6 Modern analytical techniques · Explain · 5 marks

## Mark scheme (5 marks)

1. The fruit juice sample is injected into the gas chromatograph / GC
2. Different components travel through the column at different speeds / are separated by their different retention times
3. The separated components are fed into the mass spectrometer
4. The mass spectrometer produces a fragmentation pattern / mass spectrum for each component
5. The mass spectrum of the unknown additive is compared to a database / library of known spectra to identify it

## 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 Edexcel A-Level Chemistry (9CH0)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-food-scientist-suspects-that-a-f1f53532) · Published by Druglandscape Ltd.