Study on Butachlor Microemulsion

[Objective] The properties of butachlor microemulsion were studied for developing a new formulation of new pesticides.[Method]AT method was used to determine the pseudo-ternary phase diagram to confirm the formulation of butachlor microemulsion.Through the measurement of electrical conductivity,the W/O and O/W types in microemulsion region of butachlor/emulsifier/water system were confirmed and the change of phase behavior during preparation process was discussed.[Result]The dilution stability,low temperature stability,heat stability,ageing stability,density and viscosity etc.of butachlor microemulsion met the requirement of the experiments,which demonstrated the qualified quality of butachlor.The density decreased linearly with the increase of temperature and the change of viscosity with temperature conformed to Andrade equation.[Conclusion]The research was helpful to the application of butachlor microemulsion in pesticide formulation.

Residue and Degradation Dynamics of Bensulfuron-methyl·Mefenacet 4.2 g/kg Granule in Paddy Field

This study was conducted to determine the safety of bensulfuron-methyl and mefenacet in rice ecosystem. A field experiment was carried to reveal residual dynamics and final residue of bensulfuron-methyl.mefenacet 4.2 g/kg granule in rice and paddy system in Hangzhou, Changsha and Nanning of China during 2010 to 2011. The results showed that the average recoveries of bensulfuron-methyl and mefenacet spiked in the paddy soil, paddy water, rice, husk and rice plant at the 3 concentration levels of 0.05, 0.10 and 1.00 mg/kg ranged from 70.78% to 116.06% with the relative standard deviations of 0.91%-10.24%. The limit of detection （LOD） values of bensulfuron-methyl and mefenacet were 0.02 mg/L, and the minimum de- tection quantities were 4.0×10-9 g. The degradation dynamics test was done by spraying at a high dose （270 kg/hm2, bensulfuron-methyl active ingredient was 64.8 g/hm2, mefenacet active ingredient was 1 069.2 g/hm2） by direct spreading method 5-7 d after transplanting, and the final residual test carried out at a low dose （180 kg/hm2, bensuifuron-methyl active ingredient was 43.2 g/hm2, mefenacet active in- gredient was 712.8 g/hm2） and a high dose （270 kg/hm2）. The degradation research of bensulfuron-methyl and mefenacet in paddy water, soil and rice plant suggested that the degradation curves accorded with the first-order kinetics equation, the aver- age half life of bensulfuron-methyl was 5.35, 3.05 and 3.71 d in water, soil and rice plant, respectively, and the average half life of mefenacet was 3.61, 3.29 and 3.88 d in water, soil and rice plant, respectively. The final residues of bensulfuron-methyl and mefenacet were not detected in normal harvest paddy soil, rice straw, husk and brown rice.

生物炭影响地带性土壤等温吸附丁草胺的特征及关键机制

为解析土壤理化性质与生物炭添加效果之间的相关性,明确生物炭影响地带性土壤等温吸附丁草胺的特征及关键机制,本研究采用9种不同理化性质地带性土壤,加入系列用量稻壳生物炭,考察了丁草胺在生物炭-土壤混合体中的等温吸附特征。结果表明:在不同生物炭添加剂量条件下,丁草胺在土壤中的吸附等温线均遵循Freundlich吸附模型,生物炭添加显著增加了9种地带性土壤对丁草胺的吸附能力[模型平衡常数(Kf)增加],降低了线性吸附的程度[模型指数(1/n)降低]。生物炭添加剂量越高,丁草胺吸附容量越大。热力学计算结果显示,在0.5%~2%生物炭添加条件下,丁草胺在地带性土壤中的吉布斯自由能为-16.30~-21.67 kJ·mol^(-1),表明吸附过程是自发且有利的。皮尔森相关性分析结果表明,土壤有机碳与Kf增长率呈显著负相关,说明土壤可溶性有机质抑制生物炭对丁草胺的吸附。多元线性回归方程分析结果显示,当土壤未添加生物炭时,土壤有机碳、pH、黏粒、粉粒4种土壤理化性质对Kf值的解释能力高达99%,而当生物炭添加为0.5%、1%、2%时,土壤有机碳、pH、黏粒、粉粒4种土壤理化性质对Kf值的解释能力分别下降至83%、70%、90%。通径系数研究表明,生物炭添加剂量从0上升至1%时,土壤黏粒和土壤粉粒对丁草胺吸附的直接作用系数增大,而有机碳和pH对丁草胺吸附的直接作用系数减小。研究表明,生物炭输入改变了丁草胺的吸附特征,土壤黏粒和土壤粉粒等土壤质地因素对丁草胺吸附产生重要影响。

除草剂丁草胺对泥鳅体内6种代谢与免疫相关酶的抑制作用

目的研究除草剂丁草胺对泥鳅(Misgurnus anguillicaudatus)体内重要器官过氧化物酶(POX)、非特异性酯酶(NSE)、碱性磷酸酶(ALP)、酸性磷酸酶(ACP)、琥珀酸脱氢酶(SDH)和腺苷三磷酸酶(ATPase)等6种代谢与免疫相关酶活力的影响。方法将泥鳅暴露在不同浓度的丁草胺中96 h,解剖取其心脏、肝胰脏、鳃、头肾、胃和肠等6种器官,采用冰冻切片、酶组织化学及光密度分析技术检测酶活力变化。结果POX在头肾中活性显著较高,其余器官中活性均较低;高浓度丁草胺显著抑制头肾POX活性,但显著促进肝胰脏、胃和肠POX活性。NSE在肝胰脏中活性显著较高,心脏中活性显著较低;高浓度丁草胺对除心脏和胃以外的体内器官NSE活性具有显著抑制作用。ALP在胃中活性显著较高,心脏和头肾中未检测出明显的酶活性;高浓度丁草胺显著抑制胃和肠ALP活性,对肝胰脏和鳃ALP活性无显著影响。ACP在胃和肠中活性显著较高,心脏中活性显著较低;高浓度丁草胺显著抑制肝胰脏、鳃、头肾、胃和肠ACP活性,对心脏ACP活性无显著影响。SDH在心脏中活性显著较高,鳃和头肾中未检测出明显的酶活性;高浓度丁草胺显著抑制心脏、肝胰脏和胃SDH活性,对肠SDH活性无显著影响。ATPase在心脏中活性显著较高,头肾和肠中活性显著较低;高浓度丁草胺显著抑制心脏、肝胰脏和头肾ATPase活性,但对胃和肠ATPase活性具有显著促进作用。结论丁草胺可能通过抑制心脏SDH和ATPase活性影响泥鳅的血液循环,通过抑制胃和肠ALP和ACP活性降低泥鳅对营养物质的消化和吸收能力,通过抑制肝胰和头肾NSE、ACP和ATPase活性损害泥鳅的解毒与免疫防御功能。

Synergistic Effects of Several Additives on Herbicidal Activity of Bensulfuron-methyl

[ Objective] The aim was to select the best additives of bensulfuron-methyl. [ Method ] Taking radish as the testing plant, the synergistic effect of five common additives including Span 60, methyl olelate, silicone oil I, Tween 20 and detergent on the herbicidal activities of bensulfuron-methyl were tested in the la- borotory. [ Results ] The effects of the mixture of various additives and bensulfuran-methyl on relative stem control effect of radish, relative inhibition rate against stem length, relative inhibition rote against abeveground fresh weight, relative inhibition rote aginst root length and root fresh weight were studied, and the results showed that Span 60 and methyl olelate had stronger synergistic effect on the herbicidal activities of bensulfuron-methyl, and the synergistic effect of detergent was the weakest. [ Conclusion ] Span 60 and methyl olelate could be used as the synergistic agents of bensulfuron-methyl, and the study could provide references for se- lecting the additives of bensulfuron-methyl.

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） ceils 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.

Adsorption characteristic of bensulfuron-methyl at variable added Pb^(2+) concentrations on paddy soils

The combined pollution of heavy metal Pb^2＋ and bensulfuron-methyl （BSM）, originating from chemical herbicides, in agroecological environments has become commonplace in southern China. The adsorption of BSM on three paddy soils in the presence of Pb^2＋ was examined using high-performance liquid chromatograph （HPLC）. Results indicated that adsorption of BSM could accurately be described by a Freundlich isotherm equation with correlation constant （R） 〉 0.98, irrespective of the presence of spiked Pb^2＋. Of the various factors influencing BSM sorption, soil pH appeared to be the most influential. The constant Kf of Freundlich isotherm equation tended to increase with increasing Pb^2＋ concentration in soil which indicated that the spiked of Pb^2＋ in paddy soils would promote the sorption of BSM. AGo of BSM in three paddy soils was less than 40 kJ/mol in all treatments, indicating the adsorption of BSM is mainly physical in nature. The elution of soil dissolved organic matter （DOM） enhanced the adsorption of BSM in paddy soils. The mechanisms involved in the promotion effects of the spiked Pb^2＋ on BSM adsorption might be the modified surface characteristics of paddy soil solids due to the soil acidification and the increase of soil organic matter concentration because of DOM binding.

Analysis of culturable and unculturable microbial community in bensulfuron-methyl contaminated paddy soils

To investigate the influence of bensulfuron-methyl(BSM)on culturable microbial quantities and unculturable microbial community structures,conventional and molecular biological methods were employed in five BSM treated soils with three replications,respectively. The results obtained with traditional culture-dependent methods showed that a low-level of BSM had slight and transient effects on culturable microorganisms;nevertheless,high concentration of BSM resulted in a dramatic decrease in bacterial colony fo...

Rapid degradation of bensulfuron-methyl upon repeated application in paddy soils

Rapid degradation of bensulfuron-methyl upon repeated application in paddy soils was studied. The results showed that the DT _ 50 of bensulfuron-methyl was reduced from 16 d to 9 d in soil with one-year bensulfuron-methyl application. Rapid bensulfuron-methyl degradation was happened to previously untreated soil by addition 5% rapid bensulfuron-methyl adapted soil and was inhibited following pre-treatment with broad-spectrum antibiotic chloramphenicol. In bensulfuron-methyl adapted soil mineralisation of 14 C labeled bensulfuron-methyl to 14 CO_2 occurred at a faster rate than with previously untreated soil. It was concluded that rapid bensulfuron-methyl degradation upon repeated application is probably linked to the adaptation of soil bacteria which can utilize bensulfuron-methyl as a source of carbon and energy.

Effect of Bensulfuron-Methyl on Growth of Chlorella pyrenoidosa

To study the growth effects of differing concentrations of bensulfuron-methyl on Chlorella pyrenoidosa and to evaluate the ecological risk, the effects of bensulfuron-methyl on the growth and the content change of chlorophyll and protein in Chlorella pyrenoidosa were studied through 96 h acute toxicity tests. Bensulfuron-methyl accelerated the growth of algae at lower concentrations （〈 1 mg L^-1） with content increase of chlorophyll or protein, and it inhibited the growth of algae at higher concentrations （〉 5 mg L^-1）. The content of chlorophyll or protein in algae cells reduced with the increasing concentration of bensulfuron-methyl, exhibiting the good concentration-effect relationship. The 96 h-EC50 of bensulfuronmethyl upon the algae was 15.7 mg L^-1 Bensulfuron-methyl has inhibiting effect on the growth of Chlorella pyrenoidosa and is low in toxicity.

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.

Research Progress in Microbiological Degradation of Bensulfuron-Methyl Herbicide

This paper reviewed the strategies and methods of screening for microorganisms having strong ability bensulfuron-methyl （BSM）, and discussed BSM degradation pathways and factors affecting its microbial metabolism prospected the research emphasis in the future to remove Finally, it

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

^(14)C-butachlor and ^(14)C-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 ^(14)C-herbicides from CR formulations were related to herbicide CR formulation and water type. Total recovery including ^(14)C-released and ^(14)C-left in formulations for each ^(14)C-herbicide was high at the 56th day after treatment. Some of the released ^(14)C-butachlor in water could be hydrolysed although under dark condition. The rate of hydrolysis was influenced by water type and formulations.

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.

Effects of temperature and pH on the inhibition of Bensulfuron-Methyl(BSM)

Bensulfuron-Methyl(BSM)is a highly active sul-fonylurea herbicide that effectively controls most an-nual and perennial broadleaf or sedge weeds in paddyfield.However,the activity of BSM is affected byseveral evironmental factors.Using corn seedlings asmaterial,we found that under different temperatures

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。