Separation /preconcentration and Atomic Absorption Spectrometric Determinations of Cobalt, Cadmium and Lead in aqueous and biological Samples using selective solid phase sorbent

A method for the pre-concentration of some trace metals (Co (II), Pb (II) and Cd (II)) as complexes with ammonium pyrrolidine dithio-carbamate (APDTC) was proposed using a mini – column filled with Amberlite IR- 120 resin. Metal ions were adsorbed on IR-120 as their pyrrolidine di thiocarbamate complexes, then analytes retained on the resin were eluted by 1mol L-1 nitric acid in acetone and determined by flame atomic absorption spectrometry (FAAS). The effects of the analytical parameters such as sample pH, ligand amount, eluent type, resin quantity, sample volume, sample flow rate and matrix ions were investigated on the recovery of the metals from aqueous solutions. The relative standard deviation (RSD) of the method was <3%. The validation of the procedure was carried out by analysis of certified reference materials. The proposed method was applied to natural waters, wastewater, fish, canned tuna,powder milk and rice.