Simultaneous Spectrometric Determination of Cu(II), Co(II), and Ni(II) in Pharmaceutical and Environmental Samples...

A method for the preconcentration of Cu(II), Co(II), and Ni(II) based on their complex formation with the potassium salt of 2.6-dimethyl-morpholinedithiocarbamate (DMMDTC) and the Amberlite XAD-4 resin as a solid support in a column was suggested. Cu(II), Co(II), and Ni(II) were detected by using the suggested spectrophotometric method in Triton X-100 media. The analytes were adsorbed as DMMDTC complexes on Amberlite XAD-4 column at the pH range of 4-6 and eluted with 0.5 M HNO₃ in acetone. The best possible enrichment factors for trace metal ions were achieved by optimizing the experimental conditions including reagent amount, eluent type, sample and eluent flow rates, sample volume, and the effects of matrix ions. The detection limits of Cu(II), Co(II), and Ni(II) were found to be 11.2, 26.1, and 1.37 μg L^-1, respectively. The accuracy of the proposed method was confirmed by determining the analytes in two Certified Reference Materials (TMDA-70.2 Ontario Lake Water and BCR-715 Waste Water) with the recoveries of more than 90%. The proposed method was successfully applied to the environmental and pharmaceutical samples.