Atomic Absorption Spectroscopy (AAS)

Introduction -- Atomic absorption spectroscopy (AAS) is the measurement of an absorption of optical radiation by atoms in the gaseous state. The original equipment was developed by Walsh . The following is a general discussion of AAS or basic protocols for the P-E 3030B

There are three basic components for every AA spectrophotometer:

1. Light source - It is designed to emit the atomic spectrum of a particular element. Specific lamps are selected according to the element to be determined. The hollow cathode lamp (HCL) or electrodeless lamps (EDL) are widely used.

2. Sample cell - Where an atomic sample vapor is generated in the light beam from the source. This is usually done by introducing the sample into a burner system (Flame AAS) or electrically heated furnace or platform, aligned in the optical path of the spectrophotometer.

3. Specific light measurement - Includes several components:

a) a monochromator to disperse several wavelength of lights that are emitted from the light source to isolate a particular line of interest,

b) a detector to produce an electrical current that is dependent on the light intensity. This electrical current is amplified and processed by the instrument electronics to produce a signal, which is a measure of the light attenuation occurring in the sample cell and,

c) this signal is further processed to generate an instrument readout in concentration units.