Determination of Co (II) and Pd (II) by inductivity coupled plasma–atomic emission spectrometry after extraction from water and pharmaceutical samples by cloud point extraction

In this study, cloud point extraction (CPE) was used for the preconcentration and concurrent detection of cobalt (II) and palladium (II) ions in various water samples. The hydrophobic complexes were formed by the interaction of these ions with isatin-3-(4-phenyl-3-thiosemicarbazone) (IPTS) as a chelating agent. The separation of these complexes from the aqueous sample was accomplished by using Triton X-114, a nonionic surfactant. Experiments have been performed to appreciate the effects of distinct chemical parameters such as pH, chelating agent concentration, surfactant's concentration, incubation time, and temperature. After the separation process, the surfactant-rich phase was diluted with acidifying ethanol. Then, the concentration of the analytes has been specified by inductivity-coupled plasma-atomic emission spectrometry (ICP-AES). The detection limits of Co (II) and Pd(II) ions were 0.202 and 0.52 µg mL−1, respectively. The relative standard deviation (RSD, %) is lower than 5%, and the recovery % of the extracted analytes is more than 97%. The suggested method was successfully used to determine Co (II) and Pd(II) ions in natural water samples and pharmaceutical samples.