Kinetic of Transport of Technogenic Ecotoxicants through Model Membranes

The kinetics of ecotoxicant transport through the membrane was studied. The ecotoxicants studied were pecticides widely used in agriculture: lontrel (clopyralid), sencor (metribuzin), basagran (bentazon), roundup (glyphosate), kusagard (alloxydim sodium), and sethoxydim, as well as lontrel complexes with cobalt and copper. All compounds considered penetrate through the model phosphatidylcholine liposomal membranes. The transfer rate was monitored by fluorescence quenching of -ATP inside the liposomes. The mathematical model for the process was proposed, and the mass transfer rates were calculated. The octanol/water partition constants were determined. All the compounds considered were shown to accumulate in the fatty layer. The kinetics of their accumulation was studied, and the rates of accumulation in the nonpolar phase were calculated, which correlate with the complexation constants of the same compounds. Bioaccumulation of the toxicants is caused by the formation of complexes with the fatty phase (lipid part) of the cellular membranes. The toxicants under study transferred into the nonpolar phase with a considerable rate during the whole observation time, namely, 18 months.