# A pharmaceutical company produces a new painkiller tablet. Quality control chemists need to check that the tablet contains the correct substances in the correct amounts. Describe how instrumental analysis could be used to identify and determine the purity of the substances in the tablet, and explain the advantages of using instrumental methods over traditional chemical tests for this purpose.

> WJEC A-Level Chemistry (Wales) — 2.8 Instrumental analysis · Describe · 5 marks

> Quality control is essential in pharmaceutical manufacturing. Even tiny amounts of an unexpected substance, or incorrect quantities of an active ingredient, could be harmful to patients.

## Mark scheme (5 marks)

1. An instrumental method is named that can be used to identify substances in the tablet (e.g. mass spectrometry, gas chromatography, infrared spectroscopy)
2. Instrumental methods can identify very small amounts / traces of substances (high sensitivity)
3. Instrumental methods produce rapid / fast results compared to traditional tests
4. Results from instrumental methods can be compared to a database / library of known substances to identify the substance
5. Instrumental methods can determine the amount / concentration of a substance present (quantitative analysis), allowing purity to be assessed

## Key terms

- [instrumental analysis](https://www.gradenine.co.uk/glossary/instrumental-analysis)
- [purity](https://www.gradenine.co.uk/glossary/purity)

## Related

- [Revision notes for WJEC A-Level Chemistry (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" 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-pharmaceutical-company-produces-a-new-4cc393c4) · Published by Druglandscape Ltd.