Absorption profiles of flames used in atomic-absorption spectroscopy

A study has been made of the distributions of metallic atoms in their ground electronic state when an aqueous or an organic solvent containing the metal present in the solution in various combined forms is sprayed into various flames used in atomic-absorption spectroscopy. It has been found that with almost all elements studied, rich flames give greater peak absorbances than lean flames, and the flame stoichiometry determines the number of free atoms in a flame. It has also been observed that the spatial distribution of free atoms in a flame depends not only on the flame stoichiometry but also on the species which the desired metal forms in the solution and the flame, on the other anions, complexing agents, and cations present in the solution, on chemical and physical properties of the solvent, on the type of atomizer-burner and on the flame temperature.