To perform atomic absorption spectroscopy:

• The liquid sample is mixed with a specific volume of spirit and added to a flask.
• A lamp with the necessary wavelength is set as a light source. 
• A fuel-rich acetylene-nitrous oxide flame is used to vaporize the liquid sample into a gas. 
• The gas is passed through a detector that is designed to detect the absorbance of the atoms in the gas. 
• The absorbance of the solvent bank and standard solution is detected using a similar process. 
• A graph is plotted showing the absorbance against the molecule concentration in the sample.