高比活度[苯环-^(14)C]-环磺酮在好氧土壤中的降解转化研究

Study on Degradation and Transformation of High Specific Activity[Phenyl-^(14)C]-Tembotrione in Aerobic Soil

环磺酮是一种4-羟基苯丙酮酸双加氧酶(HPPD)抑制剂类除草剂,研究环磺酮在好氧土壤中的降解规律对其环境安全性评价具有重要意义。本研究以高比活度[苯环-^(14)C]-环磺酮为示踪剂,综合运用同位素示踪法并有机结合液相色谱-高分辨质谱等现代仪器分析方法,研究并明确了环磺酮在好氧土壤中的主要降解产物、降解途径及降解产物含量随时间的变化规律。结果表明,在好氧培养条件下,环磺酮母体在红壤土、潮土、黑土和褐土4种供试土壤中的降解均符合一级动力学模型,其半衰期分别为13.18、5.05、10.49和2.82 d;环磺酮在4种好氧土壤中均存在M1、M2和M3三种主要降解产物,并推断了其在好氧土壤中的降解途径;除潮土120 d采样点外,在整个培养过程中,4种土壤中降解产物含量均表现为M2(0.5%~60.8%AR)>M3(0.0~10.0%AR)>M1(0.0~3.9%AR)。本研究结果为环磺酮的环境安全性评估提供了基础数据和科学依据。

Tembotrione is a 4-hydroxyphenylpyruvate dioxygenase(HPPD)inhibitor herbicide.Studying the degradation of Tembotrione in aerobic soil is crutial for its environmental safety assessment.This study investigated the main degradation products,degradation pathways,and change pattern of degradation product content with time in aerobic soil by liquid chromatography-high resolution mass spectrometry and other modern analytical methods using high specific activity[phenyl^(14)C]-Tembotrione as a tracer.Results showed that under aerobic conditions,the degradation of Tembotrione in all the four soil samples followed a first-order kinetic model,and the half-life of Tembotrione in red loam,fluvio-aquic soil,black soil and cinnamon soil was 13.18,5.05,10.49 and 2.82 d,respectively.Three main degradation products(M1,M2 and M3)of Tembotrione were identified in the four aerobic soils,and the degradation pathway in aerobic soil was proposed.,In addition,the content of degradation products in all four soils showed the order of M2(0.5%-60.8%AR)>M3(0.0-10.0%AR)>M1(0.0-3.9%AR)during the whole incubation process,except for the 120-day sampling point of fluvio-aquic soil.Overall,this study provides more knowledge for assessing the environmental safety of Tembotrione.