Atomic absorption spectrometric method for the determination of phosphorus using the bismuth-phosphomolybdate complex

Abstract

An improved method for the determination of micro-amounts of phosphorus by atomic absorption spectrometry is described. This technique is not generally applied to the determination of non-metals as their resonance lines fall in the ultraviolet region where atmospheric absorption is a problem. An indirect method using the bismuth-phosphomolybdate complex for the determination of phosphorus is suggested. As bismuth and phosphorus are present in a 1:1 stoicheiometric ratio, the phosphorus content can be correlated with the concentration of bismuth. The condition for the formation of the complex, its extraction with isobutyl methyl ketone and the determintion of phosphorus in solution by utilising the 223.06-nm resonance line of bismuth are discussed.