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(120) Fate and behavior of estrogens and estrogenic compounds in aqueous phase. Yamamoto, Hiroshi1, Liljestrand, Howard1, 1 ABSTRACT- In this study, sorption of estrogens and some estrogenic compounds (e.g., nonylphenol and phthalate esters) onto the organic colloidal phase (e.g., humic substances) and the model biological phase in the aquatic environment are investigated. Due to several limitations of the octanol-water partitioning system as a biological partitioning model, a liposome-water system was developed as an alternative system. The liposome suspension was prepared from distearoyl-phosphatidylcholine (DSPC) and cholesterol based on the consideration of their ubiquitous existence in the cell membrane of bacteria and animals. The suspension was prepared with reversed phase evaporation method followed by rapid extrusion process to attain mean diameter of approximately 1 Key words: Estrogens, sorption, humic, liposome |
m (i.e., microbial cell size). The sorption coefficients of selected estrogens and estrogenic compounds onto organic colloids were determined by fluorescence quenching technique with inner filter correction. In addition, the sorption coefficients of those compounds into the synthetic membrane vesicles (i.e., liposomes) were determined by either fluorescence enhancement technique or equilibrium dialysis technique. The competition between organic colloids and model biological phase for the sorption of selected estrogens and estrogenic compounds was suggested.