Movement and Degradation of Metolachlor and Metribuzin in North Central Sand Region of Minnesota Under Irrigated Potato Production

Field studies were conducted to determine the dissipation and movement of metribuzin and metolachlor applied at conventional rates to a Verndale sandy loam (Udic Argiboroll) in north-central Minnesota under irrigated potato production in two years. The rapid dissipation of both metribuzin and metolachlor was found during the initial 10 to 15 days in both years) and more than 70% of the applied herbicide dissipated during this period. From 10 to 15 days after application up to the end of growing season in both years, the levels of both herbicides decreased slowly with time. Metolachlor dissipated at a slower rate than metribuzin in surface soil and could carry over to the next cropping season. Metribuzin and metolachlor were detected in only 6 and 1 of 154 soil samples in the first year and in 3 and 4 of 225 soil samples in the second year, taken from 15 to 75cm, respectively. Fifty to 67% of water samples from suction samplers at 135-cm depth contained detectable levels (>0.4μg L-1 ) of herbicides in both years. Under laboratory conditions degradation of both herbicides was much slower than their dissipation in field. Therefore, it appeared that leaching might be an important dissipation pathway for metribuzin and metolachlor under irrigated potato production.

Triazinone herbicide metribuzin induced acute liver injury: A study of animal model

Objective: To evaluate the acute toxicity effect of metribuzin at low dose on liver of mother rabbits and its fetus.Methods: Pregnant female rabbitsOryctolagus cuniculus were divided into three groups (n=5). The first group of non-treated pregnancy rabbits served as control;the second group of pregnancy rabbits were treated with 1/100 LD50 of metribuzin and the third group of pregnancy rabbits were treated with 1/50 LD50 of metribuzin. Metribuzin was added in their drinking water for 60 d before and during pregnancy. Levels of liver malondialdehyde, liver glutathione S transferase, serum glutamic oxaloacetic transaminase and serum glutamic-pyruvic transaminase were determined. Liver reduced glutathione level was also determined by a colorimetric method. And hepatic homogenate was analyzed by HPLC analysis to determine the existence of traces of metribuzin.Results: Results revealed a significant increase in level of liver malondialdehyde, glutathione S transferase, serum glutamic oxalacetic transaminase and serum glutamic-pyruvic transaminase activities in mother and fetuses rabbits of both metribuzin treatment groups as compared to the control group. However the level of reduced glutathione was decreased in mother and fetuses rabbits of both groups treated with metribuzin compared to control group. Also, the results obtained by HPLC technique showed the presence of trace metribuzin in liver cells of mothers and fetuses rabbits of the both metribuzin treated groups.Conclusions: In conclusion, this study shows that exposure to metribuzin at low concentrations causes a acute toxicity in liver of mother rabbits and its fetus, also the trace of the metribuzin detected in the liver is the origin of possible malformation of the fetuses or abortion of the rabbits.

Reduced Rates of Metribuzin and Time of Hilling Controlled Weeds in Potato

The current emphasis on reducing herbicide applications has led to an increase in alternative weed control measures. Field experiment was conducted in the spring of 2014 to examine the effect of hilling-time and reduced-rates of metribuzin and their combinations on weed infestation in potato, and to determine their impact on potato yield. Metribuzin at 0.35, 0.56, or 0.75 kg ai/ha with or without hilling 6, 7, and 8 weeks after planting (WAP) were used. Weed count, weed control visual rating, weed dry weight, potato plant height, number of shoots and leaves, root dry weight, and potato yield were collected. Results showed that metribuzin, at all tested rates, with or without hilling significantly reduced weed infestation after 50, 70, and 110 days after planting (DAP) compared to the check. Best results were obtained by a combination of metribuzin at all tested rates with hilling 6, 7, and 8 WAP. The results suggest that long season weed control and high marketable yield could be achieved by metribuzin at 0.35 kg ai/ha (53% reduction in metribuzin) supplemented with hilling (6 WAP). None of the treatments was toxic to potato plants compared to the hand-weeded plots.

Herbicidal Activity of Chlorimuron-ethyl （107 g/kg） Associated with Metribuzin （643 g/kg） on Sugar Cane Weeds and Its Effects on Soil Agrochemical Properties, in Burkina Faso

The efficiency and selectivity of chlorimuron-ethyl （107 g/kg） associated with metribuzin （643 g/kg）, against weeds which causes big damages to sugar cane, have been studied on the sugar cane field of Beregadougou. The experimental design was a Latin rectangle with eight treatments in four replications including an untreated control, manual weeding, a control product （Trifloxysulfuron-sdium 1.85% ＋ Ametryn 73.15%） and five rates of chlorimuron-ethyl associated with metribuzin. Weeds counting and weighing their dry biomass have been done using 0.25 m2 quadrants to determine their biological efficiencies. The soil nitrogen nitrate and assimilable phosphorus contents were evaluated on a spectrophotometer, those of available potassium on a flame photometer. The biological efficiency coefficients of this herbicide, varied from 12.41% to 100%, according to their dry biomass. High rates, phytotoxics, showed the best coefficients. At the sugar cane complete maturation, the higher rates of imposter led to an accumulation of nitrogen nitrate content and lower available phosphorus and potassium contents, compared to the untreated control. The rate of 1.20 kg/ha became the dose to apply against weeds and less toxic to the soil.

Effects of Vitamin C and NADH on in Vitro Proliferative Function of Human Lymphocytes Exposed to Pesticides （Mancozeb and Metribuzin）

Antioxidants such as vitamin C and NADH can protect against pesticide adverse effects on immune function. The aim of this work was to study the in vitro effects of vitamin C and NADH on the proliferative responses of human lymphocytes exposed to pesticides （Mancozeb fungicide and Metribuzin herbicide） and on Thl and Th2 cytokine secretion. Their possible protective role on intracellular stress oxidative induced by pesticides was also investigated. Peripheral blood lymphocytes were isolated using differential centrifugation on a density gradient of Histopaque. They were cultured with mitogen concanavalin A （Con A）, Mancozeb and Metribuzin （50 μM） in the presence or the absence of vitamin C （50 μM） or NADH （50 μM）. Proliferation （MTT assay）, IL-2, INFγ and IL-4 （Elisa kits）, oxidative markers （intracellular superoxide anion, hydroperoxides, carbonyl proteins, GSH, catalase and SOD） were determined, The results showed that pesticides were immunosuppressive and decreased cytokine secretion with a shift away from to Thl phenotype. These immunomodulatory properties were accompanied by an increase in lymphocyte intracellular oxidative stress. The presence of vitamin C or NADH, in the medium, exhibited protective effects in human lymphocytes by inhibiting pesticide---induced lymphocyte proliferation suppression, inflammatory status and oxidative stress generation. In conclusion, vitamin C and NADH can result in a safe and effective method to reduce pesticide adverse effects and help to restore immune function.

Comparative study of metal oxides and phosphate modification with different mechanisms over g-C_(3)N_(4) for visible-light photocatalytic degradation of metribuzin

In this work,a comparative study of three frequently employed modification techniques to g-C_(3)N_(4)(CN)nanosheets for the photocatalytic degradation of metribuzin(MET)under visible-light irradiation has been carried out in detail.The modification methods were coupling TiO_(2)nanoparticles(TO)as electron acceptors,nano-sized Fe_(2)O_(3)(FO)to construct a Z-scheme nanocomposite,and phosphate(HP)modification to promote O_(2)adsorption.The steady-state and transient-state surface photovoltage spectra and transient photoluminescence(PL)spectra confirmed that all the three modification techniques enhanced the charge separation with prolonged lifetimes and presented degradation activities in the order of TO/CN[FO/CN[HP/CN.The TO/CN nanocomposite showed the highest photocatalytic activity for MET degradation,with a sixfold higher rate than bulk CN.Liquid chromatography–tandem mass spectrometry and radical trapping experiments indicated that the increased activity was related to the synergetic effect of two radicals(·O^(2-) and ·OH)involved in the photocatalytic degradation pathway,which was different from the·OH radical-dominated pathway of bulk CN.This work reveals the importance of charge separation and the influence of the radical pathway and provides guidance for the design of high-efficiency photocatalysts.

气相色谱-质谱法同时测定粮谷及油籽中多种酰胺类除草剂残留量

粮谷及油籽样品经丙酮-水提取，经去脂和弗罗里硅土固相萃取小柱净化，气相色谱-质谱（GC—MS）选择离子监测模式（SIM）对净化液进行检测；一次进样，便可对粮谷及油籽样品中的9种酰胺类除草剂及常混用的莠去津和嗪草酮等除草剂残留进行准确定量和确证。除草剂回收率为63％～96％；相对标准偏差为2．1％～11．2％；定量下限为0．02～0．05mg/kg。该法快速、灵敏、准确，各项技术指标均满足农药残留检测的要求。

嗪草酮与脱氧核糖核酸相互作用的研究

采用电化学方法，结合紫外-可见分光光度法、荧光光度法、粘度法和与变性脱氧核糖核酸（DNA）的作用研究了嗪草酮（M）与DNA的作用机制，并通过研究嗪草酮对溴化乙锭-天然DNA体系的影响，以及天然DNA和变性DNA与嗪草酮的作用的不同，得出嗪草酮与DNA分子发生类似溴化乙锭（EB）嵌插作用的结论，形成DNA—M1：1型的超分子化合物DNA—M。求得结合常数β=1．8×10^5L／mol。DNA加入量在1×10^-5～1．5×10^-4mol／L范围内，DNA浓度与峰电流降低值之间存在线性关系。

乙草胺和嗪草酮水基性制剂的研制及其应用

改变传统的将乙嗪合剂加工成乳油或可湿性粉剂的惯例,研制出一种新型的水基性除草剂———28 % 乙嗪悬乳剂。温室盆栽试验表明,乙草胺与嗪草酮混用对防除某些杂草有互补作用。采用孙云沛法测定表明,两者混用对牛筋草和苘麻有增效作用,对马唐和反枝苋有相加作用。对杂草马唐、藜和反枝苋使用后测定,28 % 乙嗪悬乳剂对玉米、大豆、花生的选择性指数分别为2-57 ,2-28 和2-14 ,2-17 。经1996 ～1998 年田间试验表明,除沙性土壤外,28 % 乙嗪悬乳剂可以在大豆、玉米、花生地作为土壤处理型除草剂安全使用,适宜的剂量为2250 ～3000 g/hm2 ,对一年生单、双子叶杂草的防效在多雨年份可达94-2 % ～99-0 % ,干旱年份可达81-2% ～84-5 % 。并对28% 乙嗪悬乳剂的关键加工技术,物化性能和安全使用技术作了论述。

选择性甲基化合成赛克津中间试验研究

以作者研究成功的 4 氨基 6 特丁基 3 甲硫基 1,2 ,4 三嗪 5 (4H) 酮 (赛克津 )合成新方法小试技术条件为依据 ,进行了赛克津中间试验放大过程工艺研究。中间试验结果 :以中间体 4 氨基 6 特丁基 3 巯基 1,2 ,4 三嗪 5 (4H) 酮 (简称三嗪 )为原料计 ,收率 >90 % ,有效成分含量 >90 %

降解嗪草酮微生物菌剂的制备及稳定性研究

通过富集培养分离出嗪草酮降解菌N1,降解菌在固体平板上培养,菌落大,表面粗糙,扁平,不规则,为质地软、稍有光泽的白色菌落,直径为5-7 mm。菌体细胞为杆状,末端方,成短或长链,菌体大小为1.0-1.2μm×3.0-5.0μm。将N1降解菌制成菌剂,用气相色谱法进行定量分析,通过单因素试验确定菌剂中载体配比、接种菌液量、加入营养液量、发酵时间、烘干温度等影响因子的优势条件,设计正交试验确定最优菌剂制备条件：m（豆粕）∶m（麦麸）∶m（木屑）∶m（硅藻土）比例为60∶20∶15∶5,接种菌液量为15%,营养液量为10%,发酵时间为48 h,烘干温度为30℃。在上述条件制备的菌剂对嗪草酮的降解率为79%。该菌剂在25℃下保存50 d后对嗪草酮仍有较高的降解效果。

嗪草酮在玻碳电极上的伏安行为及测定

用循环伏安法及微分脉冲阴极溶出伏安法,在玻碳电极(GCE)上研究了嗪草酮在不同底液中的伏安特性,发现在B-R(Britton-Robiagon)电解质溶液(pH2)中于-0.524 V(vs.SCE)左右产生1个尖锐的阴极还原峰.嗪草酮的浓度在1.0×10-6～1.0×10-4mol/L范围内与峰电流呈良好的线性关系(r=0.998 7).对其反应机理作了初步探讨.

嗪草酮70%可湿性粉剂在大豆上残留动态研究

为了评价嗪草酮70%可湿性粉剂在大豆上的残留动态和使用安全性,应用气相色谱法,在大豆及土壤中进行了残留动态试验。测定结果表明,嗪草酮在大豆植株中半衰期为8.5～14.4d,土壤中半衰期为15.8～21.3d;大豆中最终残留量均为未检出。以此结果制定合理使用准则:按有效成分795g/hm2土壤喷雾使用1次。

分子印迹技术在线富集测定玉米中嗪草酮残留

为了对玉米中的嗪草酮残留进行高效的分离、富集和测定,以嗪草酮为模板分子,采用原位聚合法制备了分子印迹聚合物,并将印迹聚合物作为固相萃取柱用于玉米样品的前处理过程,建立了在线富集液相色谱法测定玉米中嗪草酮残留的分析方法。研究结果表明,嗪草酮印迹聚合物具有良好的亲和性和特异选择性,在0.01-0.50μg/m L质量浓度范围内有良好的线性关系（r=9991）,最低检出浓度（S/N=3）为1.8×10^-3μg/m L,在0.01、0.05、0.10 mg/kg 3个浓度的添加水平下,方法的平均回收率在80.9%-94.5%之间,相对标准偏差低于5.98%。方法简化了样品前处理步骤,提高了检测灵敏度,缩短了分析时间,无基质干扰,精密度和准确度高,可应用于玉米中嗪草酮残留的分析检测。

高锰酸钾/亚硫酸氢钠氧化嗪草酮后消毒副产物的生成趋势及毒性研究

本文研究了不同pH条件下高锰酸钾/亚硫酸氢钠(PM/BS)对农药嗪草酮(MET)的氧化降解,预氧化后续氯化过程中消毒副产物(DBPs)的变化和毒性评估,同时高锰酸钾(PM)氧化作为对照组.研究表明,PM/BS预氧化较PM预氧化能加大污染物质MET的降解效率,两种预氧化过程中MET的降解率在酸性条件下最大且随着pH的升高而降低,DBPs的生成量和毒性都随着pH的升高而增大.碱性条件下降解率低却生成了大量的二氯乙腈,导致DBPs的生成量和毒性大幅增加,值得引起重视和注意,本文对此种现象产生的原因进行了详细探讨.PM/BS系统降解污染物需要控制在酸性条件下进行,既能增大降解效率,又能降低DBPs的毒性.

大口径毛细管气相色谱法测定嗪草酮原药含量研究

采用自制的SE-30大口径毛细管柱,以邻苯二甲酸二丁酯为内标物,不分流进样,FID检测,建立了测定嗪草酮原药的色谱分析方法。结果表明,在所选择的色谱条件下,嗪草酮和内标物在6.0min内很好地分离;嗪草酮与内标物质量比与它们的峰面积比有良好的线性关系,相关系数为0.9999;样品加标回收率为99.1%-100.4%;相对标准偏差为0.079%。

嗪草酮农药生产环合废水物化处理工艺研究

采用絮凝-树脂吸附组合工艺对嗪草酮农药生产环合废水进行物化预处理。实验确定的最佳工艺条件为：（1）絮凝—絮凝剂为10%硫酸铝溶液（W/W）,投加量为8%（V/V）,废水pH为6-9,快速搅拌1 min（150-180 r/min）,慢速搅拌15 min（80-100 r/min）;（2）树脂吸附—双柱串联吸附：上柱液pH=3.0左右,吸附温度为常温,吸附流速2.5 BV/h;（3）树脂脱附—脱附剂1 BV H2O＋1 BV 4%NaOH＋1 BV 2%NaOH＋2 BV H2O,流速1 BV/h,温度为80℃。实验结果表明：在最佳工艺条件下对该废水进行处理,COD降至3 650 mg/L以下,去除率达到85%以上;废水的BOD5/COD由0.23提高到0.43,为后续生化处理提供了良好的条件。

乙草胺和嗪草酮混合悬乳剂的气相色谱分析

本文报道了乙草胺和嗪草酮混合悬乳剂的气相色谱分析方法。在４％ＯＶ－２２５／ＣｈｒｏｍｏｓｏｒｂＷ－ＨＰ（８０～１００目）色谱柱上乙草胺、嗪草酮和内标物癸二酸二丁酯的保留时间分别为１０．４５，１７．２４和１２．９分钟，实现了良好的分离。乙草胺的标准偏差、变异系数和回收率分别为０．１０９、０．５６％和９９．６％；嗪草酮的标准偏差、变异系数和回收率分别为０．３１４、１．５２％和１００．１％。

降解菌N1对嗪草酮的降解效果研究

【目的】研究降解菌N1对土壤中嗪草酮的降解效果，为嗪草酮土壤残留的修复处理提供支持。【方法】以嗪草酮高效降解菌N1为供试菌种，通过土壤接种，分析N1菌株对土壤嗪草酮的降解能力，并研究嗪草酮初始含量、N1菌株接种量、土壤pH、反应温度对降解效果的影响。【结果】当土壤中的嗪草酮含量为20 mg/kg时，在灭菌土壤中添加N1菌株1011 CFU/g后，嗪草酮的降解率可由10.69%提高到54.07%，而在未灭菌土壤中添加N1菌株后，嗪草酮的降解率由19.04%提高到66.42%。当嗪草酮的初始含量为20 mg/kg、N1菌株接种量为1011 CFU/g、土壤pH=7～8、反应温度为30 ℃时，N1降解嗪草酮的效果较好。【结论】降解菌N1可明显提高土壤嗪草酮的降解率。

传统法制备嗪草酮印迹聚合物

农药嗪草酮应用广泛,它的残留问题引起了人们的普遍关注,发展快速准确的检测方法势在必行。而分子印迹技术因其独特的优点使它成为痕量残留快速检测的一种较好的方法。采用传统法制备嗪草酮印迹聚合物,以甲基丙烯酸(MAA)为功能单体,N,N-亚甲基双丙烯酰胺为交联剂,甲苯为溶剂,在50℃时聚合得到选择性、吸附性最佳的印迹聚合物。