Development of liquid chromatography method for determination of diphenylether group herbicides from biological samples and investigation of pesticide-protein interactions

Within the scope of this thesis, the necessary parameters for the analysis of Aklonifen and Bifenox pesticide compounds using the HPLC method were found and simultaneous analyzes were made depending on these parameters. For this purpose, the best conditions for analyzes were determined by using mobile phase organic solvent percentage, buffer solution molarity, column, flow rate, temperature and pH. In our method, which was developed by completing the optimization and validation processes, a better and more effective separation and better recovery, diagnostic limit and lower limit of determination values were obtained compared to many analysis methods in the literature. In line with the calculated validation parameters, it can be said that the developed method is an accurate, sensitive and stable method. As a result, in line with the data obtained, a fast, sensitive, precise, easily applicable, accurate, economical and does not require any pre-separation process has been developed for the simultaneous analysis of Aklonifen and Bifenox pesticides from biological samples. It has been shown statistically that the developed analysis method can be successfully applied to the simultaneous analysis of these substances from biological samples. In addition, it was aimed to examine the interactions of the pesticide compounds used with human serum albumin (HSA), which is the main carrier protein in the circulatory system, by fluorescence spectroscopy and calculation techniques, and the results obtained from fluorescence and absorption spectroscopy confirmed the complexation between ACF/BIF and HSA. The increase in KSV values with increasing temperature showed that the ACF/BIF induced quenching of HSA fluorescence is dynamic quenching. At room temperature, the binding affinities of pesticides with HSA were Kf=3.47 × 105 M-1 for the ACF–HSA complex; For the BIF–HSA complex, Kf was found to be =1 × 105 M-1. An increase in the binding constant values was observed with the increase in temperature. Numerical evaluation of thermodynamic data (ΔS= +0.864 kJ mol–1K-1 for ACF-HSA complex, ΔH = 225.43 kJ mol–1 and ΔS= + 1.11 kJ mol–1K-1 for BIF-HSA complex The results obtained as a result of ΔH = 304.63 kJ mol-1) showed that hydrophobic bonds were more effective in the formation of ACF-HSA and BIF-HSA complexes.