Environmental Analysis of Cypermethrin and its Degradation Products After Forestry Applications
作者:
T.J. Class,
期刊:
International Journal of Environmental Analytical Chemistry
(Taylor Available online 1992)
卷期:
Volume 49,
issue 4
页码: 189-205
ISSN:0306-7319
年代: 1992
DOI:10.1080/03067319208027571
出版商: Taylor & Francis Group
关键词: Cypermethrin;gas chromatography;mass spectrometry;high performance liquid chromatography;chiral separations;environmental degradation
数据来源: Taylor
摘要:
Cypermethrin and alphamethrin ([1R, cis, αS]- and [1S, cis, αR]-cypermethrin) are pyrethroid insecticides used in agriculture, forestry, and public health hygiene. After forestry applications of cypermethrin against bark beetles diastereo- and enantioselective analyses of pyrethroid residues are performed by gas chromatography (GC) with electron capture (ECD) and mass spectrometric (MS) detection, or by achiral and chiral high performance liquid chromatography (HPLC). The major soil metabolites of cypermethrin, i.e. 2,2-dimethyl-3-(1,1-dichlorovinyl)-cyclopropylic acid and 3-phenoxybenzoic acid, are analyzed as methyl esters by GC-MS with electron-impact (EI) ionization. On spruce bark cypermethrin persists several months as surface films of 1 μg/cm2.In soil it is detected as long as seven months after treatment at levels of 0.15–0.7 μg/g. Sunlight-induced cis, trans isomerization on bark and leaves results in an excess of trans-cypermethrin isomers. In soil cis-cypermethrin isomers are more persistent than their corresponding trans-isomers. Enantioselective HPLC demonstrates chiral discrimination of a pair of trans-cypermethrin enantiomers. Analysis of soil metabolites is less meaningful since traces of the investigated products are formed from pyrethroid residues during the extraction and derivatization procedures.
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