Atomic absorption spectroscopy (AAS) is used to detect and measure the presence of metallic elements in biological systems. It is widely used in a number of fields ranging from pharmaceuticals and agriculture to environmental control and mining. 

In the pharmaceutical industry, AAS is used to detect metals in pharmaceutical products and oil products. In the agriculture and environmental control industries, AAS is used to purify water, soil, and other environmental samples. AAs are also used in the mining industry to detect metals as impurities in alloys and other mixtures.