Forensics Atomic Absorption Spectroscopy

Atomic absorption spectroscopy Atomic absorption spectroscopy (AAS) was developed in the early 1950’s by Alan Walsh. It works on the principle that certain elements absorb certain wavelengths, and this level of absorption is characteristic of each element. Also, electrons in atoms can only exist in particular energy levels, and when an electron moves to a higher energy level, electromagnetic radiation of a particular frequency is absorbed. Because of this, we can measure the concentration of certain elements in a sample depending upon how much of a specific wavelength is absorbed. AAS is a form of quantitative analysis as oppose to a qualitative analysis, as the element being tested must be known. This is because a wavelength must be emitted which is specific to the element being tested, as certain elements only absorb certain wavelengths. This also allows for an individual element to be analysed even if other elements are present in a sample. The AAS is used to determine the concentrations of over 60 elements, mostly metals, and can measure in parts per million.