Atomic Absorption Spectrometer

Introduction to AASIntroduction to AASThe technique was introduced in 1955 by Walsh in Australia (A.Walsh, Spectrochim. Acta, 1955, 7, 108)

Alan Walsh 1916-1998

http://www.science.org.au/academy/memoirs/walsh2.htm#1

The application of atomic absorption spectra to chemical analysis

The Instrument

The instrument consists of:1.A flame2.Lamps to produce the correct wavelength of

light3.A detector4.A system to aspirate solutions into the flame5.A computer to control the experiment

Instrumentation

The Instrument

On the left is the flame (behind the grid) and the spectrometer. The two bottles contain water used for flushing the tubing and for diluting solutions that are too concentrated. The round object is a pump.On the right is a cabinet containing the lamps shown on a later slide.The flame, like all large burners, is vented at the top.

Measurement - Standards

A set of standards ready to be aspirated into the flame. This instrument automatically dilutes the solution.

Aspiration of the Solution Being Measured

A sample of maple syrup ready to be aspirated into the flame.

Cathode--- in the form of a cylinder, made of the element being studied in the flame

Anode---tungsten

Hollow Cathode Lamp

The Lamps From bottom to top, the lamps are for Mg, Ca, K, and a combination of Fe, Co, Ni, Mn, Cu, and Cr. Each element uses a specific wavelength of light.

flame

Air – acetylene

Air- propane

Air- hydrogen

Nitrous oxide – acetylene

Auxiliary oxidant

Fuel

Flame

Common Flame

Colors Produced by Different Ions

The following slides show the colors of different ions in the flame. The differences in intensity of the colors is, in part, due to differences in concentration.

The Calcium Flame The calcium flame is red. This is intensely red because the calcium content is high.

The Copper Flame

The Potassium Flame

The Manganese Flame

The Cobalt Flame

The End & Thank you