MICELLAR SPECTROPHOTOMETRIC DETERMINATION OF COPPER IN THE VARIOUS SAMPLES OF MILK

Milk is a complex system where analysis of metal ions is a difficult task due to the presence of interfering materials. The formation of a coloured complex between the metal and a coloured or colourless ligand is the basis for the development of spectro-photometric methods. The aim of this study is to analyze and estimate copper present in various samples of milk (i.e., cow, buffalo, goat, camel, soya, and powdered milk) by micellar spectrophotometry method. For this purpose, the ligand N-(2’-Pyridyl)-2-hydroxy-benzamide (NPHB-2) was synthesized by the reaction of 2-aminopyridine with salicylic acid, which is a weak acid and is found to be soluble in alcohol, acetone, and chloroform. It is insoluble in water at a pH less than 7. In addition to the solution of this ligands to copper (II) solution in the presence of micellar medium, a yellowish-green or light green coloured complex is formed immediately. It has been observed that in the presence of a micellar medium, solubility, as well as absorption intensity, has been found to be increased. This phenomenon has been used to develop a novel and selective micellar spectrophotometric method for the determination of metal ions in various samples of milk.