Environmental toxicities evaluation and experimental design of polymeric drugs based on polyacrylamide quaternary ammonium salts
[Objective]Because of the huge damage caused by soil-borne fungal diseases in agriculture,polyacrylamide quaternary ammonium salts(PAM-QAS)have been introduced to control soil-borne fungal diseases,such as banana Fusarium wilt,which is caused by Fusariumoxysporum f.sp.cubense(Foc).As a random copolymer of acrylamide and acrylamide quaternary ammonium salt,PAM-QAS shows significant improvement properties on soil and good antifungal activities against soil-borne fungal diseases,such as Foc.Thus,PAM-QAS has a good application prospect in the control of soil-borne fungal diseases and improving soil.However,traditional small molecular quaternary ammonium salts have been well-known to show high environmental toxicities,greatly limiting their application.Thus,visually evaluating the environmental toxicities of PAM-QAS based on exact application environments has become an urgent issue in the design and application of PAM-QAS.In this work,multiple experiments were designed to visually demonstrate the low environmental toxicity of PAM-QAS.[Methods]To visualize PAM-QAS,a very small amount of a fluorescent group(FL)was introduced into PAM-QAS to obtain fluorescent-labeled PAM-QAS(PAM-QAS-FL).Thus,its adsorption and leaching characteristics in soil could be observed intuitively.From the soil adsorption and leaching experiments,the actual environmental toxicities of PAM-QAS after soil adsorption could be evaluated using fish oral acute toxicity and earthworm toxicity experiments,which gave a good perspective for the field application of PAM-QAS.[Results]The soil adsorption and leaching experiments intuitively showed that under an application rate of 0.6 g per kilogram of dry soil in the field,which was about three times the commonly applied amount,PAM-QAS-FL could be stably adsorbed and retained in the soil,with only a few free PAM-QASs leaching into environmental water.Thus,the impact of PAM-QAS on the environment could be greatly reduced.The fish acute toxicity of simulated rain leaching solution containing PAM-QAS and soil(LC50L),the fish acute toxicity of a suspension containing PAM-QAS and soil(LC50s),and the earthworm toxicity of PAM-QAS(LC50)were all higher than 600 mg per kilogram of dry soil.Meanwhile,the LC50L,LC50s,and LC50(earthworm)for small molecule quaternary ammonium salt(benzalkonium chloride(BC))were about 70,150,and 150 mg per kilogram of dry soil,respectively.These results demonstrate that compared with BC,the environmental toxicity of PAM-QAS is significantly reduced,and it is safe for both fish and earthworms.[Conclusions]By simulating the effects of drugs infiltrating groundwater with rainwater and mixing with soil and water in practical production applications,LC50L and LC50s were introduced to evaluate the fish toxicity of soil leaching solutions and water/soil/drug mixtures,respectively.A more accurate environmental toxicity assessment method for PAM-QAS was thus established.This work covers several aspects,such as structure characterization and application of functional polymers,qualitative detection of polymeric drugs in complex environments,and environmental toxicity evaluation of drugs.It is comprehensive and exploratory to a certain extent and is conducive to improving students'comprehensive quality,scientific research,and innovation ability.
polyacrylamide quaternary ammonium saltfluorescent group modificationsoil adsorption characteristicsenvironmental toxicity evaluation
NETL
NSTL
万方数据
