Study On The Environmental Toxicology And Fate Of Phenthoate And Acetofenate

The Organophosphorus pesticides(OPs)and organochlorine pesticides(OCPs)are two kinds of significant pesticides.They have the high pharmacodynamic effect on the target organisms,and also contaminate the nontarget organisms in the environment,so it's important to study their environment behaviours.This paper investigates the environment behaviour of the Ops-Phenthoate(PTA)and the OCPs-Acetofenate(ATF)from different points of views by using the water flea Daphnia magna which is generally acknowledged standard test aquatic, the plasma proteins which are the toxicological properties of xenobiotics moleculars and the aquicolous algae as the investigative objects.Firstly,a method for chiral separation of two phenthoate enantiomers was developed by high performance liquid chromatography,and the acut aquatic toxicity of phenthoate to Daphnia magna were assayed with an enantioselective way.And the result indicted that the difference of aquatic toxicity between phenthoate isomers is significantly obvious.Then we investigated the interaction between phenthoate and bovine serum albumin(BSA)using tryptophan fluorescence quenching and acetylcholinesterase(AChE)activity inhibition.In the discussion of the mechanism,it was proved that the fluorescence quenching of BSA by PTA is a result of the formation of a PTA-BSA complex.Quenching constants were determined using the Stern-Volmer equation to provide a measure of the binding affinity between PTA and BSA.The thermodynamic parametersâ–³G,â–³H,andâ–³S at different temperatures were calculated,which suggested that the association between PTA and BSA changed the molecular conformation of BSA and the electrostatic interactions play a major role in PTA-BSA association.Furthermore,the inhibition of AChE by PTA in the presence of different BSA concentrations was evaluated,this indicted that BSA can reduce the inhibition of AChE by PTA.Finally,the accumulation and degradation of acetofenate,a toxic and persistent organochlorine pesticide by Chlorella pyrenoidosa and Anabaena flosaquae was investigated.At the concentrations of 1mg/L,5 mg/L and 10mg/L,the daily average degradation rate per day of ATF by C.pyrenoidosa were 0.185mg/L,0.690mg/L and 0.854mg/L, respectively;the maximum accumulation of ATF by C.pyrenoidosa were 0.575mg/g FW,0.753mg/g FW and 0.821mg/g FW,respectively;the daily average degradation rate per day of ATF by A.flosaquae were 0.171 mg/L,0.626mg/L and 0.800mg/L,respectively;the maximum accumulation of ATF by A.flosaquae were 0.560 mg/g FW,0.737mg/g FW and 0.787mg/g FW,respectively.