Role of organic solvents in atomisation:
The organic solvents of low molar mass like alcohols, ethers, and ketones enhance the absorption peaks by increasing rate of aspiration, nebulisation efficiency, formation of finer droplets, and more efficient evapouration or combustion of the solvent. Therefore, their presence makes the sample solution more dilute and the advantage is lost. Thus, the analyte is extracted into a suitable solvent and the organic phase is directly aspirated into the flame. This method increases the atomisation efficiency and eliminates a number of chemical interferences.
A transient signal that lasts for a few seconds is produced in GFAAS whereas in flame AAS a steady absorption signal is obtained.