RELEASE OF ^(14)C—BUTACHLOR AND ^(14)C—OXADIAZON FROM CR FORMULATIONS INTO WATER

14C-butachlor and 14C-oxadiazon could be released from four kinds of CR formulations into water respectively, and the release percentage of each herbicide increased with time, which could be expressed by regression equations （very obvious positive relationship）. The release percentages of 14C-herbicides from CR formulations were related to herbicide CR formulation and water type. Total recovery including 14C-released and 14C-left in formulations for each 14C-herbicide was high at the 56th day after treatment. Some of the released 14C-butachlor in water could be hydrolysed although under dark condition. The rate of hydrolysis was influenced by water type and formulations.

Biodegradation of acetanilide herbicides acetochlor and butachlor in soil

The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matters addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil SDBS (sodium dodecylbenzene sulfonate) mixtures and soil HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half life of acetochlor and butachlor in soil alone, soil SDBS mixtures and soil HA mixtures were 4.6d, 6.1d and 5.4d and 5.3d, 4.9d and 5.3d respectively. The biodegradation products were hydroxyacetochlor and 2 methyl 6 ethylaniline for acetochlor, and hydroxybutachlor and 2,6 diethylaniline for butachlor.

Effects of butachlor on microbial enzyme activities in paddy soil

This paper reports the influences of the herbicide butachlor( n butoxymethl chloro 2', 6' diethylacetnilide) on microbial respiration, nitrogen fixation and nitrification, and on the activities of dehydrogenase and hydrogen peroxidase in paddy soil. The results showed that after application of butachlor with concentrations of 5.5 μg/g dried soil, 11.0 μg/g dried soil and 22.0 μg/g dried soil, the application of butachlor enhanced the activity of dehydrogenase at increasing concentrations. The soil dehydrogenase showed the highest activity on the 16th day after application of 22.0 μg/g dried soil of butachlor. The hydrogen peroxidase could be stimulated by butachlor. The soil respiration was depressed within a period from several days to more than 20 days, depending on concentrations of butachlor applied. Both the nitrogen fixation and nitrification were stimulated in the beginning but reduced greatly afterwards in paddy soil.

The Toxic Mechanism of High Lethality of Herbicide Butachlor in Marine Flatfish Flounder,Paralichthys olivaceus

The toxic mechanism of herbicide butachlor to induce extremely high lethality in marine flatfish flounder,Paralichthys Olivaceus,was analyzed by histopathological examination,antioxidant enzymes activities and ATP content assay.Histopathological examination of gill,liver and kidney of exposed fishes showed that gill was a target organ of butachlor.The butachlor seriously impaired the respiration of gills by a series of lesions such as edema,lifting and detachment of lamellar epithelium,breakdown of pillar cells,and blood congestion.The dysfunction of gill respiration caused suffocation to the exposed flounder with extremely high acute lethality.Antioxidant enzyme activity assay of the in vitro cultured flounder gill(FG) cells exposed to butachlor indicated that butachlor markedly inhibited the antioxidant enzyme activities of Superoxide dismutase(SOD),catalase(CAT) and glutathione peroxidase(GPX).Furthermore,along with the decline of antioxidant enzyme activities,ATP content in the exposed FG cells decreased,too.This infers that the oxidative stress induced by butachlor can inhibit the production of cellular ATP.Similar decrease of ATP content was also observed in the exposed flounder gill tissues.Taken together,as in FG cells,butachlor possibly induced a short supply of ATP in pillar cells by inhibiting the antioxidant enzyme activities and then affecting the contractibility of the pillar cells,which in turn resulted in the blood congestion and suffocation of exposed flounder.

Genotoxicity of the Pesticide Dichlorvos and Herbicide Butachlor on Rana zhenhaiensis Tadpoles

Genotoxicity of dichlorvos and butachlor on erythrocytes of Rana zhenhaiensis tadpoles was investigated by the alkaline single-cell gel electrophoresis assay or comet assay.Tadpoles were treated for 24h in the laboratory with different concentrations of the testing agents,2.256,4.512,6.768,9.024,11.280mg/L for dichlorvos and 0.292,0.584,0.876,1.168,1.460mg/L for butachlor,to use the comet Assay to test for the significance of dosage responsiveness to an increase in DNA damage,asmeasured by themean DNA tail length-to-width ratio.The concentrations of 4.512mg/L dichlorvos and 0.876mg/L butachlor resulted in highly significant increases in DNA damage of the tadpoles.There were linear correlations between themean DNA tail length-to-width ratio and the concentrations of the two test substances.Our results showed that the two commonly used agricultural chemicals caused dose dependent DNA damage of amphibians,and that comet assaymight be a useful tool formeasuring DNA damage of tadpoles exposed in the field.

The degradation of oxadiazon by nonthermal plasma with a dielectric barrier configuration

To explore the feasibility of a degradation approach by non-thermal plasma and the corresponding degradation pathways,studies on the oxadiazon removal in synthetic wastewater by a dielectric barrier discharge plasma reactor were investigated.The loss of the nitro group,dechlorination and ring cleavage is mainly involved in the non-thermal plasma degradation pathways of oxadiazon in a solution based on the OES and LC-MS analysis.Detection of EC25 and the production of the chlorine ion and nitrate ion further demonstrate the feasibility and validity of the approach.The conditions with a proper applied voltage,solution flow rate,oxygen flow rate,and solution pH contribute to the plasma degradation processes with a degradation ratio of over 94%.

Determination of herbicides atrazine and butachlor in soil by high performance liquid chromatography

A Liquid Chromatographic procedure was described for simultaneous determination atrazine and butachlor in soil with a diode-array-detector(DAD).Unequivocal identification by Rt alone,however,is sometimes difficult. The UV spectra offer a viable alternative to Rt.The distinct differences in Rt and UV of the peaks are noteworthy. UV spectra are extremely helpful and served to accurately identify the various component. Soil samples containing herbicide residues were extracted on a shaker using dichloromethane. The extractions were finally concentrated to 1 ml by a K-D concentrator then the residues were quantitated by peak height. Detection limits for atrazine and butachlor were 0.1 ppb and 0.8 ppb respectively. Fortified at 5.0 ng,10. 0 ng, and 50.0 ng levels,the recoveries of atrazine (n= 8)were 88.4%,95. 1% and 91. 6%. Fortified at 10. 0 ng,50. 0 ng and 80.0 ng levels,the recoveries of butachlor (n=8) were 89. 8%,91.2% and 87.4%,respectively.

Adsorption of Herbicide Butachlor in Cultivated Soils of Golestan Province, Iran

Butachlor is a non-ionic herbicide that has been applied widely for agriculture, especially in paddy fields. Through batch equilibration experiments, the adsorption characteristics of butachlor were investigated in eight cultivated soil samples collected from Golestan Province, Iran. The data obtained from adsorption equilibrium experiments fitted the linear equation very well. Results showed that butachlor had weak to moderate adsorption capability in different soils. Trend of butachlor adsorption was similar to the order of abundance of organic carbon in the soils. The Gibbs free energy values were found negative and adsorption was spontaneous and exothermic in nature. Statistical analysis showed that organic carbon, CEC (cation exchange capacity), and the Rt ratio (ratio of TNV to organic matter content) were the more effective parameters governing butachlor retention and mobility in soils.

Optimization of Solid Phase Microextraction Procedure Followed by Gas Chromatography with Electron Capture Detector for Pesticides Butachlor and Chlorpyrifos

In this study, headspace solid phase microextraction (HS-SPME) followed by gas chromatography using electron capture detection system (GC-ECD) were developed for the determination of chloraacetanilide (butachlor) and chlorpyrifos presented in biological samples. Different parameters affecting the extraction procedure were optimized including extraction time (30 minutes), extraction temperature (80°C), sample volume (3 mL), sample pH (2), added NaCl (0.3 gram) and sample stirring rate (400 rpm). Different concentrations of 1 - 100 ng/ml were applied for butachlor and a linear calibration curve was obtained. Furthermore, a similar linearity was obtained for chlorpyrifos, using a concentration range of 1 - 250 ng/ml. The limit of detection (LOD) obtained for butachlor and chlorpyrifos were 0.088 and 0.53 ng/ml respectively. The optimized methods for both compounds were validated using two concentrations of 25 and 50 ng/ml in spiked urine samples. Obtained recoveries of spiked urine samples were 83.06% - 99.8% with RSD of lower than 11%. Optimized technique was simple, inexpensive, solvent free and fast in comparison with other conventional methods and had compatibility with the chromatographic analytical system. This method offers low detection limits to analyze pesticides in urine samples that are very important in the exposure monitoring in occupational health.

噁草酮及其混剂对花生田杂草防效及对花生安全性评价

为明确250 g/L噁草酮EC及其混剂在防除花生田杂草中的应用前景,本研究利用田间小区药效试验评价了250 g/L噁草酮EC及其混剂对花生田杂草的防效及对花生的安全性。试验结果表明,250 g/L噁草酮EC单独施用时,田间施用有效剂量为450 g/hm^(2)时防效较好,药后30 d总草株防效及鲜重防效分别为79.7%和83.2%,与900 g/L乙草胺EC总草株防效和总草鲜重防效相近。混配施用时,250 g/L噁草酮EC 450 g/hm^(2)与960 g/L精异丙甲草胺EC 720 g/hm^(2)混用的防效最佳,药后30 d总草株防效和总草鲜重防效分别为83.3%和87.1%,与240 g/L乙氧氟草醚EC 180 g/hm^(2)+960 g/L精异丙甲草胺EC 720 g/hm^(2)总草株防效和总草鲜重防效相当,且增产率达27.3%。因此,250 g/L噁草酮EC262.5~450 g/hm^(2)与960 g/L精异丙甲草胺EC 720 g/hm^(2)混用可用于花生田杂草防除,杂草防效良好,对花生安全性高,增产效果显著。

丁草胺暴露对雄性褐菖鮋精细胞发育的干扰

丁草胺是全球范围内使用最广泛的酰胺类除草剂之一。目前丁草胺对非目标生物的潜在毒性研究较多,但有关丁草胺对近海鱼类生殖毒性的研究鲜有报道。以近海鱼类褐菖鮋为研究对象,探讨丁草胺对海洋鱼类精细胞发育的影响及机制。以环境浓度(2、20和200 ng·L^(-1))的丁草胺对雄性褐菖鮋暴露50 d后,其精巢成熟精细胞数量下降,发育早期阶段的精原细胞与精母细胞数量上升,精巢雄激素睾酮(T)水平下降,Caspase-3活性上升,γ-谷酰胺转移酶(γ-GT)活性下降。相对荧光定量PCR分析结果显示,促卵泡激素受体基因(FSHRβ)与促黄体生成激素受体基因(LHRβ)mRNA表达量被抑制。这表明,丁草胺对雄性褐菖鮋有明显的生殖毒性,精巢支持细胞功能被抑制引起睾酮水平降低,进而导致精子发生被抑制。精巢细胞凋亡也是原因之一。

环境浓度的丁草胺暴露对雌性褐菖鲉卵巢发育的干扰

丁草胺是使用最广泛的酰胺类除草剂之一,目前丁草胺对鱼类的生殖毒性研究集中于淡水种类,近海鱼类鲜有报道。本研究以分布于我国东南海域的近海经济鱼类褐菖鲉(Sebastiscus marmoratus)为受试对象,探讨丁草胺对海洋鱼类卵巢发育的影响及机制。褐菖鲉在以环境相关浓度(2、20、200 ng/L)的丁草胺暴露50 d后,褐菖鮋卵巢生殖细胞发育受到不同程度抑制,卵巢17β-雌二醇(E2)水平下降,Caspase-3活性上升。相对定量PCR分析结果显示,卵巢芳香化酶基因(CYP 19 s)及雌激素受体基因(ERβ)表达量下降。结果表明:丁草胺对褐菖鮋具有明显的生殖毒性,卵巢CYP 19 s基因与ERβ基因表达被抑制而导致卵巢雌激素水平的下降引起卵细胞在发育早期的细胞凋亡是主要原因。

丁草胺对褐菖鲉肝脏抗氧化系统的影响

为探究丁草胺对褐菖鲉组织抗氧化系统的影响,以环境浓度水平的丁草胺对褐菖鲉进行50 d的暴露,检测其肝脏谷胱甘肽(GSH)、丙二醛(MDA)含量的变化及谷胱甘肽硫转移酶(GST)和超氧化物歧化酶(SOD)活性的变化.结果显示:GSH含量在丁草胺暴露后呈下降趋势,且各浓度处理实验组均与对照组存在显著性差异(P<0.05);MDA含量呈升高趋势,其中低浓度组升高不显著(P>0.05),而中浓度组与高浓度组均出现显著性升高(P<0.05);GST活性呈下降趋势,其中低浓度组下降不显著(P>0.05),而中浓度组与高浓度组均出现显著性下降(P<0.05);SOD活性在低浓度组上升但不显著(P>0.05),而中、高浓度组均出现显著性下降(P<0.05).实验结果表明,丁草胺暴露会导致褐菖鲉机体组织抗氧化防御系统的功能出现损伤.

气相色谱法同时测定西草净、丁草胺和噁草灵

采用气相色谱法，以癸二酸二正丁酯为内标物，对新研制的复合型稻田除草剂26％丁··西乳油进行了一次性定量分析。色谱条件为5％SE-302m×3mm的玻璃柱，柱温为210℃，检测温度为230℃。方法的回收率为98．62％～100．77％，线性相关系数大于0．999。方法准确、简便、快速。

60%丁草胺·噁草酮乳油防除水稻旱直播田杂草试验

2011年采用大田药效试验的方法,研究60％丁草胺·噁草酮乳油防除水稻旱直播田杂草的防除效果、最佳使用剂量及安全性.该药剂在水稻旱直播田播后苗前土壤喷雾处理,推荐使用药量为720～900 g a.i./hm2,可有效地防除稗草、千金子等禾本科杂草及碎米莎草、水虱草等莎草科杂草.在推荐使用剂量内对水稻安全,高浓度处理会产生部分药害,后期可以恢复.

丁草胺和乙草胺对蚯蚓CAT和SOD活性的影响

研究土壤中丁草胺和乙草胺对蚯蚓抗氧化酶系CAT和SOD的影响.结果表明,随着暴露时间的延长,蚯蚓体组织的CAT和SOD活性先增大后降低,与对照相比,蚯蚓CAT和SOD活性表现为低浓度诱导和高浓度抑制;在一定暴露时间内,随着丁草胺和乙草胺浓度的增加,CAT和SOD活性呈抛物线型剂量-效应相关关系;丁草胺和乙草胺暴露浓度与蚯蚓CAT和SOD活性均呈现出抛物线型暴露时间-胁迫效应的相关关系.不同酶对毒性效应的响应域值不同,其敏感性大小为:SOD>CAT.根据两个指标对污染物浓度响应域值的不同,建立剂量-效应关系与时间-效应关系.

丁草胺对土壤微生物数量和酶活性的影响

在模拟土壤生态系统中研究了丁草胺对土壤微生物数量和酶活性的影响。试验表明,低浓度(2mg/kg)和中等浓度(4mg/kg)丁草胺对微生物数量影响不大;而高浓度(10mg/kg)处理则有明显抑制效应,但在21d后也基本恢复到对照水平。丁草胺对土壤酸性磷酸酶、碱性磷酸酶、脲酶、蔗糖酶均产生了一定的抑制作用,并随浓度升高而增强,随着时间的延长,抑制作用逐渐消失,酶活性恢复至对照水平。丁草胺对土壤过氧化氢酶的影响与其他酶不同,表现出一定的刺激作用。

噁草酮在液相中的光化学降解研究

以高压汞灯为光源 ,研究了草酮在环己烷、甲醇、乙腈、丙酮及水溶液中的光化学降解。结果表明 :在环己烷、甲醇、乙腈、水中 ,草酮光降解效应显著 ,其半衰期分别为 4 .4 5、15 .34、5 7.5 8、5 4.6 9min;草酮在丙酮溶剂中降解缓慢 ,半衰期为 2 93.83min;丙酮对草酮在水中的光解有显著的光敏作用 ,光敏效应与丙酮的量显著相关 ,光敏效率最高达 95 .84 %。

丁草胺在土壤中的吸附及环境物质的影响

在实验室条件下 ,采用振荡平衡法研究了丁草胺在土壤中的吸附行为 ,以及腐殖酸 (HA)、阴离子表面活性剂十二烷基苯磺酸钠 (SDBS)、阳离子表面活性剂十六烷基三甲基溴化铵 (HDAB)、NH4NO3和土壤粒度对吸附的影响 .结果显示 ,土壤对丁草胺具有较强的吸附能力 ,HA和NH4NO3明显地增加了土壤对丁草胺的吸附 . 40mg·l- 1 和 2 2 4 0mg·l- 1 的SDBS也可以提高丁草胺在土壤中的吸附能力 . 40mg·l- 1 的HDAB能降低丁草胺的吸附 ,而2 0 0mg·l- 1 的HDAB则可以增加这种吸附 .丁草胺在沙土中的吸附强于在粘土中的吸附 .在同样含沙量条件下 。

丁草胺在环境中降解行为的研究进展

丁草胺是一种酰胺类除草剂 ,杀草活性高 ,选择性好 ,是我国用量最大的除草剂之一 ,大量使用对环境造成了一定的影响。综述丁草胺在土壤环境和水环境中降解方面的研究进展 ,分析影响丁草胺降解的主要因素。在土壤环境中 ,丁草胺的微生物降解、光解为主要的降解途径 ,土壤湿度、有机质及重金属是影响丁草胺在土壤中降解的重要因素。光解和水解是丁草胺在水体中降解的主要途径。不同的光源、光敏剂、催化剂、氧化剂及某些农药对丁草胺在水中的光解有不同程度的影响 ,而温度和 pH是影响丁草胺水解的主要因素。