Determination of heavy metals in drinking water of Isparta province using chemometric methods

In this thesis study, city tap water samples were studied. Spectrophotometry method was applied, which allows simultaneous detection of Lead, Copper and Cadmium, which are possible heavy metals caused by natural sources, by forming complexes with APDC ligand. Partial least squares method (PLS) and Principal Component Regression (PCR) methods have been successfully applied without the need for any preliminary separation. The applied chemometric methods were applied to the data obtained from the UV-Visible Spectroscopy method. In this research, in order to minimize the error, first the optimum conditions of pH, ligand amount, holding time and metal concentration-absorbance relationship parameters were ensured. After optimum conditions were achieved, the calibration concentration set was prepared as thirty-two solutions and the correlations between the investigated metals were determined. After the correlations were determined, the validation set containing the fifteen metals studied was used with the appropriate solvent in the concentration range of 0.10-0.50 µg/mL for Pb2+ and Cu2+ and in the concentration range of 0.10-0.90 µg/mL for the purpose of verifying the calibration set with appropriate results. . For Cd2+, µg/mL was prepared in dilute hydrochloric acid (0.1 M HCl) solution. The absorption spectrum of the prepared validation set in the range of 200 – 450 nm was recorded and PCR and PLS methods, which are among the chemometric methods studied, were applied to the obtained data separately and the results were interpreted with each other. The estimated sum of squares of errors (PRESS) and standard calibration error (SEC) values of each method were found, and the ANOVA test was applied to test the accuracy and precision of the applied methods by evaluating the results. The results obtained from the ANOVA test are discussed. It has been determined that the developed method gives accurate and sensitive results in determining heavy metals that give absorbance in very close proximity to each other. As a final process, the developed methods were analyzed by applying the developed methods to the mains water of Isparta province and the mains water taken from Süleyman Demirel University Campus, and it was concluded that the developed method is highly applicable for routine analysis in the determination of heavy metals in city tap water, without requiring any preliminary separation process. The methods applied are simple, fast, reproducible and inexpensive. The fact that the amount of metals (Pb, Cu, Cd) in the investigated water sample was below the values determined by WHO, Turkish Standards Institute and the Ministry of Health proved the reliability of city mains water.