Influence of Soil Properties on the Enantioselective Dissipation of the Herbicide Lactofen in Soils

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• 作者：Jinling Diao ; Chunguang Lv ; Xinquan Wang ; Ziheng Dang ; Wentao Zhu ; Zhiqiang Zhou
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2009
• 出版时间：July 8, 2009
• 年：2009
• 卷：57
• 期：13
• 页码：5865-5871
• 全文大小：760K
• 年卷期：v.57,no.13(July 8, 2009)
• ISSN：1520-5118

文摘

A scheme was developed to elucidate the dissipation behaviors of the two enantiomers of the herbicide lactofen in soils using a normal-phase high-performance liquid chromatograph (HPLC) with UV detector and a column with a cellulose-tri-(3,5-dimethylphenylcarbamate)-based chiral stationary phase (CDMPC-CSP). Eight soils with a wide range of soil properties were studied. Racemic and the enantiopure (S)-(+)- and (R)-(−)-lactofen were incubated under aerobic and anaerobic conditions. The data from sterilized controls indicated that the dissipation of lactofen was biological. The dissipation was shown to be enantioselective with (S)-(+)-enantiomer being degraded faster than the (R)-(−)-enantiomer, resulting in residues enriched with (R)-(−)-lactofen when the racemic compound was incubated. Lactofen was configurationally stable in soil, showing no interconversion of (S)-(+)- to (R)-(−)- enantiomer and vice versa. Significant correlations of the enantioselectivity, expressed as ES = (k_(S) − k_(R))/(k_(S) + k_(R)) of lactofen with soil pH were observed under aerobic and anaerobic conditions. In addition, we found that the enantioselectivity correlated with the soil texture rather than the organic carbon.