Photodegradation of the Herbicide Imazethapyr in Aqueous Solution: Effects of Wavelength, pH, and Natural Organic Matter (NOM) and Analysis of Photoproducts

被引：37

作者：

Espy, Ryan ^{[1
]}

Pelton, Emily ^{[1
]}

Opseth, Annie ^{[1
]}

Kasprisin, Jonathan ^{[1
]}

Nienow, Amanda M. ^{[1
]}

机构：

[1] Gustavus Adolphus Coll, St Peter, MN 56082 USA

来源：

JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY | 2011年 / 59卷 / 13期

基金：

美国国家科学基金会;

关键词：

imazethapyr; imidazolinone; natural organic matter; photolysis; photodegradation; photoproducts; PHOTOCHEMICAL DEGRADATION; ABIOTIC DEGRADATION; MASS-SPECTROMETRY; PHOTOLYSIS; IMIDAZOLINONE; IMAZAPYR; IMAZAMOX; IMAZAQUIN; BEHAVIOR; CROPS;

D O I：

10.1021/jf200573g

中图分类号：

S [农业科学];

学科分类号：

09 ;

摘要：

The photodegradation of imazethapyr, 5-ethyl-2-(4-isopropyl-4-methyl-5-oxo-4,5-dihydroimidazol-1H-3-yl)nicotinic acid, has been investigated in phosphate buffers and in buffered solutions containing natural organic matter (NOM). Imazethapyr degrades most quickly under 253.7 nm light and at pH values >4. The presence of NOM in solution caused the reaction rate constants for the photodegradation to decrease, with higher concentrations of NOM having a larger effect. Calculations suggest light screening is the major effect of the NOM. Seven photoproducts have been identified, and a photodegradation mechanism is proposed.

引用

页码：7277 / 7285

页数：9

共 36 条

[1] Imazethapyr aqueous photolysis, reaction quantum yield, and hydroxyl radical rate constant [J].