Influence of Soil Properties on the Enantioselective Dissipation of the Herbicide Lactofen in Soils
Influence of Soil Properties on the Enantioselective Dissipation of the Herbicide Lactofen in Soils
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DOI：
10.1021/jf9006856
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发表时间：
2009-07-08
影响因子：
6.1
通讯作者：
Zhou, Zhiqiang
中科院分区：
文献类型：
--
作者：
Diao, Jinling;Lv, Chunguang;Zhou, Zhiqiang
采用正相高效液相色谱法（HPLC）和纤维素-三（3，5-二甲基苯基氨基甲酸酯）手性固定相（CDMPC-CSP），研究了除草剂乳氟草醚的两种对映体在土壤中的消解行为。研究了8种具有广泛土壤性质的土壤。外消旋和对映体纯（S）-（+）-和（R）-（-）-乳氟醚在有氧和厌氧条件下孵育。来自灭菌对照的数据表明，乳螨酯的消散是生物学的。耗散显示为对映选择性的，其中（S）-（+）-对映异构体比（R）-（-）-对映异构体降解更快，当孵育外消旋化合物时，导致残留物富含（R）-（-）-乳芬。乳螨酯在土壤中的构型稳定，未显示（S）-（+）-与（R）-（-）-对映体的相互转化，反之亦然。在好氧和厌氧条件下，乳氟菌醚的对映体选择性（ES =（k（（S））- k（（R）/（k（（S））+ k（（R）与土壤pH值呈显著正相关。此外，我们发现，对映体选择性与土壤质地，而不是有机碳。
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.