Unidad de Productos Fitosanitarios, Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA), Ctra. de La Coruna, Km. 7.5, 28040 Madrid, Spain.
J Agric Food Chem. 2010 Mar 10;58(5):3068-76. doi: 10.1021/jf9034173.
Aqueous photolysis of clethodim herbicide in the presence of natural substances such as humic acids (HA), nitrate, and Fe(III) ions has been investigated. The photodegradation rate of clethodim was retarded in the presence of HA compared to ultrapure water, while nitrate ions had no effect. On the other hand, water containing different concentrations of Fe(III) ions enhanced degradation of this herbicide. Clethodim transformation gave rise to the formation of nine byproducts, some of them, to the best of our knowledge, described for the first time in this work. The identification of these photoproducts has been accomplished by coupling liquid chromatography to quadrupole time-of-flight mass spectrometry. The main transformation reactions observed for clethodim were photoisomerization to the Z-isomer, S-oxidation of E- and Z-clethodim isomers giving rise to sulfoxide diastereoisomers, reduction of the oxime moiety to yield clethodim imine, oxidative cleavage of the C-S bond, and S-oxidation of clethodim imine leading to the formation of imine ketone and imine sulfoxide.
在天然物质如腐殖酸（HA）、硝酸盐和 Fe(III)离子存在的情况下，对草铵膦除草剂的水相光解进行了研究。与超纯水相比，腐殖酸的存在会减缓草铵膦的光降解速度，而硝酸盐离子则没有影响。另一方面，含有不同浓度 Fe(III)离子的水会增强这种除草剂的降解。草铵膦的转化生成了 9 种副产物，其中一些是我们首次在这项工作中描述的。通过将液相色谱与四极杆飞行时间质谱联用，对这些光产物进行了鉴定。观察到的草铵膦的主要转化反应包括光异构化为 Z-异构体、E-和 Z-草铵膦异构体的 S-氧化生成亚砜非对映异构体、肟部分还原生成草铵膦亚胺、C-S 键的氧化断裂以及草铵膦亚胺的 S-氧化生成亚胺酮和亚胺亚砜。
