Chemical detection - instrumental methods

Elements and compounds can be detected and identified using a variety of instrumental methods. Some instrumental methods are suited to identify elements, while others identify compounds. At this level students should know about the applications of the techniques in broad terms, and with appropriate guidance, be able to interpret spectra. They do not need to know how the instruments work (although teachers will probably find this sort of background knowledge useful when preparing to teach this topic)

There are many opportunties in this topic to explore the benefits and ethics of technological developments. Industry needs rapid and accurate methods for the analysis of its products. There have also been increasing demands from society for safe and reliable monitoring of our health and environment and for crime detection. Research into new compounds and materials needs more sophisticated analysis. The development of modern instrumental methods has been aided by the rapid progress in technologies such as electronics and computing.

Various factors have influenced the development of instrumental methods. With modern methods it is possible to achieve greater sensitivity, so smaller amounts of material can be used, or much smaller amounts of a trace element or compound can be detected in a mixture, e.g. testing water for pollutants and drug testing of athletes.

These methods enable:
• more accurate data
• automation of analysis, multiple samples efficiently analysed
• a greater range of analytical techniques;

Modern analytical laboratories are far more versatile than ever before; they are, however, often expensive, requiring special training and some giving results that can only be interpreted by comparison with known specimens.

Whilst this list provides a source of information and ideas for experimental work, it is important to note that recommendations can date very quickly. Do NOT follow suggestions which conflict with current advice from CLEAPSS, SSERC or recent safety guides. eLibrary users are responsible for ensuring that any activity, including practical work, which they carry out is consistent with current regulations related to Health and Safety and that they carry an appropriate risk assessment. Further information is provided in our Health and Safety guidance.