Simultaneous Preconcentration and Determination of Cu(II), Ni(II), and Co(II) in Food and Environmental Samples by the Application of Chelate Adsorption on Amberlite XAD-1180

A simultaneous preconcentration and determination procedure for solid phase extraction on AXAD-1180 as 2,6-dimethylmorpholinedithiocarbamate (DMMDTC) chelates and spectrophotometric determinations of Cu (II), Ni (II), and Co (II) in food and environmental samples is proposed in the present work. The effect of some SPE parameters, such as reagent amount, sample pH, eluent type, concentration, and volume, sample and eluent flow rate, and sample volume, on trace metal ion recovery (R%) for the method developed in the standard model solution medium was investigated. Cu(II), Ni(II), and Co(II) retained as DMMDTC complexes on Amberlite XAD-1180 were eluted with 10 mL of 1 M HNO3 (in acetone). Foreign ions were also studied individually on the recovery of trace metal ions using the developed method. Cu(II), Ni(II), and Co(II) ions were preconcentrated and separated from the sample using the developed SPE method, and their concentrations were simultaneously determined using the UV-Vis spectrophotometric method. The spectrophotometric determination was made by measuring the absorbance of colored chelates of metal ions complexed with DMMDTC in a surfactant medium (1% Triton X-100) at wavelengths of 460, 328, and 342 nm for Cu(II), Ni(II), and Co(II), respectively. To test the method’s accuracy, certified reference materials (CRM 1204 waste water and TMDA-70.2 Ontario lake water) were analyzed using the proposed method, and metal recoveries were calculated to be between 97.1 and 100.7%. The proposed method worked well with the wheat flour sample. Wheat flour has Cu(II) and Ni(II) contents of 2.16 μgmL−1 and 0.56 μgmL−1, respectively.