Simultaneous determination of Co2+, Ni2+, Cu2+ and Zn2+ ions in foodstuffs and vegetables with a new Schiff base using artificial neural networks.

New complexes of Co(2+), Ni(2+), Cu(2+) and Zn(2+) with a recently synthesized Schiff base derived from 3,6-bis((aminoethyl)thio)pyridazine were applied for their simultaneous determination with artificial neural networks. The analytical data show the ratio of metal to ligand in all metal complexes is 1:1. The absorption spectra were evaluated with respect to Schiff base concentration, pH and time of the color formation reactions. It was found that at pH 10.0 and 60min after mixing, the complexation reactions are completed and the colored complexes exhibited absorption bands in the wavelength range 300-500nm. Spectral data was reduced using principal component analysis and subjected to artificial neural networks. The data obtained from synthetic mixtures of four metal ions were processed by principal component-feed forward neural networks (PCFFNNs) and principal component-radial basis function networks (PCRBFNs). Performances of the proposed methods were tested with regard to root mean square errors of prediction (RMSEP%), using synthetic solutions. Under the working conditions, the proposed methods were successfully applied to simultaneous determination of Co(2+), Ni(2+), Cu(2+) and Zn(2+) in different vegetable, foodstuff and pharmaceutical product samples.