Absorbtion, Distribution And Degradation Of Triafamone In Rice Plant And The Potted Circumstance

A method for residue determination of triafamone is developed using UPLC-MS/MS. Via this method, environmental behavior of the triafamone was studied, such as photolysis, hydrolysis and soil degradation, which is beneficial to apply reasonably. The study helped understand the migration and transformation rule of the triafamone, in order to provide the scientific basis for the environmental safety assessment after applied.A rapid, accuracy, sensitive method for residue determination of triafamone in water, soil and rice was developed optimizing extraction clean-up and using UPLC-MS/MS. In the trial, the LOQ (limit of quantificaction) of triafamone is0.8ug/kg. Within the fortified range respectively, the average recoveries of triafamone in water and rice varied from76.0%to105.7%. The LOQ of triafamone’s metabolite I was2ug/kg. Within the fortified range respectively, the average recoveries of triafamone’s metabolite I in water, soil and rice varied from75.3%to111.8%. The LOQ of triafamone’s metabolite Ⅱ was6ug/kg. Within the fortified range respectively, the average recoveries of metabolite Ⅱ in water and rice varied from82.6%to96.5%. The relative standard deviation (RSD) of the three materials ranged from1.5%to13.3%. The results showed that the method’s sensitivity, accuracy and precision met the requirements of pesticide residue analysis.The pH value had a major impact on the rate of triafamone’s hydrolysis. Under alkaline condition the rate of triafamone’s hydrolysis was faster than under acidic condition. The slow rate is under the neutral condition. Hydrolysis half lives of triafamone in different buffer solutions with pH values of3,7and9ranged from2.7h to16.6d at30℃and50℃. Temperature had a significant effect on triafamone’s hydrolysis. When the temperature improved10℃, the rate of hydrolysis increased about three times. Via two kinds of hydrolytic way the triafamone hydrolysis products were N’-{1-amino-2-[2-(1,1-difluoro-N-methylmethylsulfonamide)-3-fluorophenyl]-2-oxoethyl}and1,1-difluoro-N-[2-fluoro-6-(6-methoxy-4-oxo-4.5-dihydro-1.3.5-triazine-2-carbonyl) phenyl] methanesulfonami de.Photolysis half live of triafamone treated by a Xe-lamp with illumination intensity4008±217Lux were11.6d.In the mixed bacteria the degradation half live of triafamone was1.8d, the rate of which was rapid. In the bacteria the triafamone reacted to its metabolite I via the reduction reaction.The half lives of triafamone were52.5d and18.0d in the sterilized and non-sterilized soil at30℃. The micro-biologic aldegradation was the main degradation pathway in soil.After applying triafamone3h, the triafamone and its metabolites were dtected in the soil culture trial which indicated the ability of acropetal translocationand systemic was strong. The secondary metabolite were produced rapidly after triafamone absorbed. The triafamone reacted to triafamone’s metabolite I and II under the action of reductase and glycosidase in rice. On the7th day, the residue of the triafamone’s metabolit I got a maximum cumulative. The residueof the triafamone’s metabolite II was the same variation tendency to the triafamone’smetabolite I which was the rate-limiting step. Thus it cuold be seen that the rice drug resistance to triafamone was the result from the good ability of metabolism in rice.