Simultaneous spectrophotometric determination of copper, cobalt, nickel and iron in foodstuffs and vegetables with a new bis thiosemicarbazone ligand using chemometric approaches

A newly synthesized bis thiosemicarbazone ligand, (21,2'Z)-2,2'-((4S,5R)-4,5,6-trihydroxyhexane-1,2-di ylidene)bis(N-phenylhydrazinecarbothioamide), was used to make a complex with Cu2+, Ni2+, Co2+ and Fe3+ for their simultaneous spectrophotometric determination using chemometric methods. By Job's method, the ratio of metal to ligand in Ni2+ was found to be 1:2, whereas it was 1:4 for the others. The effect of on the sensitivity and selectivity of the formed complexes was studied according to the net analyte signal (NAS). Under optimum conditions, the calibration graphs were linear in the ranges of 0.10-3.83, 0.20-3.83,0.23-5.23 and 032-8.12 mg 1.-1 with the detection limits of 2, 3, 4 and 10 mu g L-1 for Cu2+, Co2+, Nil and Fe3+ respectively. The OSC-PLS1 for Cu2+ and Ni2+, the PLS1 for Co2+ and the PC-FFANN for Fe3+ were selected as the best models. The selected models were successfully applied for the simultaneous determination of elements in some foodstuffs and vegetables. (C) 2015 Elsevier Ltd. All rights reserved.