Atomic Absorption Spectroscopy
A technique that measures the concentration of a metal from the light its free gaseous atoms absorb.
Formula / equation
A = εlc
Unit
ppm
In depth
The sample is atomised in a flame or graphite furnace, and a hollow cathode lamp made of the target element emits exactly the wavelengths its atoms absorb. This makes the method extremely specific, though a separate lamp is needed for each element analysed.
Examples in the real world
Determining lead in blood or calcium in milk at concentrations of a few parts per million.