1. Atomic Absorption Spectrometry
Dr Zarina Zakaria
University Malaysia Perlis

2. Instrumentation
An atomic absorption spectrophotometer consists of a light source, a sample compartment and a detector.

3. Applications
Atomic spectroscopy is one of the major tools for of trace (ppm and ppb) metallic elements in industrial and environmental laboratories.

4. Comparison Between AAS and UV/Vis Spectroscopy
Both methods are used to determine the concentration of an element in solution.
Both methods use a standard curve.
Difference between UV and IR spectroscopy is that sample must be atomised where the analyte are converted into free atom.
This is called the atomization concept.

5. Continue…….
In this concept, it is important to convert an analyte in solid, liquid or solution form to a free gaseous atom.
Sample may be atomised by:
(1) A flame atomizers
(2) Electrothermal atomizers/graphite furnace

6. Instrumentation for an Atomic Absorption Spectrometer
Instrumentation for an Atomic Absorption Spectrometer. The flowing fuel and air mixture provides the aspiration action drawing the solution sample into the flame.

7. Atomic Absorption Spectroscopy
In atomic absorption spectroscopy the radiation of the lines of the analyte are produced by the lamp; the presence of the atomic state of the analyte in the flame attenuates or reduces the intensity of the radiation.
The absorbance is proportional to the concentration of the analyte, similar to optical spectroscopy.

8. Upper Diagram is AES and the lower one is AAS
Upper Diagram is AES and the lower one is AAS. In FES the flame provides the excitation, but in AAS it provides only for the atomization .

9. Hollow Cathode Lamp
The light source in AAS is the hollow cathode lamp (HCL). The cathode is constructed of the metal or metals of the analysis. Passage of a dc voltage through the lamp produces the specific lines of those elements.

10. Atomic Absorption Spectroscopy

11. The signal from the detector is transferred to the computer, and the output registers on the monitor in a manner specified by the user.

12. Spectra output of the multi-element steel hollow cathode lamp
Spectra output of the multi-element steel hollow cathode lamp. Note the extremely sharp spectral lines.

13. Atomic Absorption Spectrometry
Most widely used method for determination of single elements in analytical chemistry
Quantification of energy absorbed from an incident radiation source from the promotion of elemental electrons from the ground state
Technique relies on a source of free elemental atoms electronically excited by monochromatic light

14. Sample Introduction in AAS
Flame
Method of supplying atom source
Utilizes a nebulizer in conjunction with air/acetylene flame
Solvent evaporates
Metal salt vaporizes and is reduced to complete the atomization process
Radiation source is a hollow cathode lamp

15. Pesanan Tolong bacakan juga topik separation the 1st topik.
Lecture notes on Infrared spectroscopy saya tak upload coz tak berkaitan.