You are here: Science > Chemistry > Chemical analysis

Chemical analysis

Testing drinking water for pollutants on a US Air Force base in Iraq, 2008 Chemical analysis is the study of the chemical composition and structure of substances. It is split into two areas. Qualitative analysis aims to discover the elements or compounds in a sample of unknown material. Quantitative analysis aims to find out the amount of each element or compound in the sample. In order to analyse a sample, first scientists often have to split it into its separate “ingredients”, using techniques such as chromatography or distillation. Then they work out the composition of the sample using chemical tests or instruments such as spectroscopes and mass spectrometers. 


Uses of chemical analysis

An archaeologist tests an ancient clay tablet using an X-ray fluorescence machine. The machine fires X-rays into the material and...Read More >>An archaeologist tests an ancient clay tablet using an X-ray fluorescence machine. The machine fires X-rays into the material and then measures how much radiation it emits in response. Different atoms emit different amounts of radiation when excited by X-rays. Chemical analysis is central to forensics, in which tests are used to detect crime. In the pharmaceutical industry, chemical analysis helps with the development of drugs and the study of their effects. In medical testing, analysis is used to check samples such as blood or urine for signs of infection. Environmental testing uses analysis to measure pollutants in the atmosphere, water or soil. Chemical analysts may also work in materials development, testing metal alloys, ceramics and polymers, in archaeology, to find out about the materials used in the past, and in space exploration, identifying rock samples from Mars, moons, asteroids or comets.
 

Forged banknote detection pens contain an iodine-based ink. The ink reacts with the starch in standard paper, turning purple. Genuine banknotes are usually printed on starch-free paper, made from cotton.

Q-files now has new sections specially written for younger readers. They are: Living world, Earth, Science, Human body, Prehistoric life, Space, History, Geography and Technology.


Find the answer