title: Photodegradation of new herbicide HW-02 in organic solvents.
abstract: HW-02 is a new organophosphates herbicide which is discovered and developed in China. The kinetics and mechanism of HW-02 photodegradation in the organic solvents were studied at 25 degrees C under the irradiation of ultraviolet light. The results showed that photochemical reaction of HW-02 in organic solvents such as n-hexane, methanol, dimethyl benzene and acetone under UV light could be well described by the first kinetic equation, and the photodegradation efficiency decreased with a order of n-hexane > methanol > xylene > acetone. The photodegradation efficiency constant of HW-02 in n-hexane, methanol, xylene and acetone were 4.951 x 10(-2), 3.253 x 10(-2), 2.377 x 10(-2) and 1.628 x 10-2 min(-1), and the corresponding half-lives were 13.99, 21.20, 29.15 and 42.56 min, respectively. By separation and identification of photoproducts using GC-MS, it could be concluded that HW-02 was photolyzed through ester cleavage, photo-dechlorination and photoisomerization of the molecule itself.
authors.affiliation: College of Urban and Environmental Science, Northeast Normal University, Changchun 130024, China. luzong1979@yahoo.com.cn
authors.forename: Zhongbin
authors.initials: Z
authors.lastname: Lu
authors.forename: Zhiguang
authors.initials: Z
authors.lastname: Hou
authors.forename: Xiumei
authors.initials: X
authors.lastname: Wang
authors.forename: Siwei
authors.initials: S
authors.lastname: Wang
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Shang
authors.forename: Xing
authors.initials: X
authors.lastname: Yuan
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry; D006540:Herbicides / Q000737:chemistry*; D010777:Photochemistry / Q000379:methods*; D010782:Photolysis; D012997:Solvents / Q000737:chemistry*
chemical_list: D006540:Herbicides; D012997:Solvents