Sensitivity of green and blue-green algae to methyl tert-butyl ether

The toxicity of methyl tert-butyl ether （MTBE） to Chlorella ellipsoidea and Aphanizomenon flos-aquae was tested and assessed for a 15-d incubation with concentrations of MTBE from high （2.00×10^4 mg/L） to low （2 mg/L）. The results showed that the toxicity was low when the concentration of MTBE was in the range 1.00× 10^4-2.00× 10^4 mg/L （the greatest inhibition of growth-rate was 70%-71%, occurred during the day 1-5）. Low concentrations （2-500 rag/L） stimulated algal growth up to the greatest effect of 85%-200% when the concentration of MTBE was 50-100 mg/L during day 3-5. The toxicity of MTBE （72-120 h EC50） was 6.65×10^3-9.58×10^3 mg/L for C. ellipsoidea and that is 1.14× 10^4-2.00× 10^4 mg/L for A. floc-aquae. We found that the toxicity and ecological risk of MTBE for the algal community structure were low and the toxicity was influenced by the duration time of the test.

Aerobic degradation of methyl tert-butyl ether by a Proteobacteria strain in a closed culture system

The contamination of methyl ten-butyl ether （MTBE） in underground waters has become a widely concerned problem all over the world. In this study, a novel dosed culture system with oxygen supplied by H2O2 was introduced for MTBE aerobic biodegradation. After 7 d, almost all MTBE was degraded by a pure culture, a member of β-Proteobacteria named as PMI, in a closed system with oxygen supply, while only 40% MTBE was degraded in one without oxygen supply. Dissolved oxygen （DO） levels of the broth in closed systems respectively with and without H2O2 were about 5-6 and 4 mg/L. Higher DO may improve the activity of monooxygemase, which is the key enzyme of metabolic pathway from MTBE to tert-butyl alcohol and finally to CO2, and may result in the increase of the degrading activity of PM1 cell. The purge and trap GC-MS result of the broth in closed systems showed that tea-butyl alcohol, isopronol and acetone were the main intermediate products.

Determination of methyl tert-butyl ether(MTBE) in Chinese fuels by gas chromatography/mass spectrometry and gas chromatography/flame ionization detector

A method was developed to determine the concentration of methyl tert-butyl ether(MTBE) in gasoline, diesel and heating oil by gas chromatography(GC) with mass spectrometry(GC-MS) or flame ionization detection(FID). The diluted gasoline was directly injected into the GC, and the complete separation of MTBE from co-eluting hydrocarbons was not required. GC/MS or GC/FID method can be used to analyze MTBE in different concentration range and have good consistency.

2D-Cell Experiment on Methyl Tert-Butyl Ether Transport in Saturated Zone of Groundwater

As an additive of gasoline,methyl ten-butyl ether(MTBE)has a higher solubility in water,which is about 20 times as high as that of benzene.This characteristic results in MTBE dissolving out of the gasoline into the soil and groundwater.Due to relative unique physicochemical behavior of MTBE it would be an ideal candidate for use in environmental forensic investigations.In order to study the transport and distribution of MTBE in saturated zone of ground water,a two-dimensional experimental cell was setup to simulate the real environment of the groundwater flow.The effects of soil and groundwater flow velocity on the MTBE transport were investigated.The results show that the mobile distance of MTBE in vertical direction was smaller than that in horizontal direction paralleling with the groundwater flow.Because the main dynamics of groundwater flow direction was convection and dispersion,the movement of MTBE is also diffusion in the vertical direction.In addition,the transport of MTBE was more quick in high permeability porous media,and the increase of groundwater flow velocity can accelerate the MTBE plume development,but the irregularity and randomness of the plume are enhanced synchronously.These research results can give some helps for the investigation of MTBE movement in the groundwater,also can make some references for other petroleum contamination behavior.

Measurements and correlation of liquid–liquid equilibrium data for the ternary(methyl tert-butyl ketone + o, m, p-benzenediol + water)system at(333.2, 343.2 and 353.2) K

In this work, liquid–liquid equilibria(LLE) data for the ternary system methyl tert-butyl ketone(MTBK)+ o, m,p-benzenediol + water were investigated at 333.2 K, 343.2 K and 353.2 K under 101.3 kPa. The performance of MTBK to extract o, m, p-benzenediol from wastewaters was estimated by partition coefficients and separation factors. The Hand and Bachman equations were both applied to check the reliability of the experimental LLE data. Furthermore, the Non-Random Two-Liquid(NRTL) and Universal Quasi Chemical(UNIQUAC) models were applied to correlate the measured LLE data. The results showed a good agreement with the determined ternary LLE data with the root-mean-square error(RMSE) values below 0.71%. MTBK was proved to be a promising extracting agent in extracting benzenediols from effluents.

Study on Pervaporation Membranes for Removing Methanol from C_5 or Methyl Tert-butyl Ether Mixtures

Several pervaporation membranes, cellulose acetate (CA), polyvinylbutyral (PVB), poly(MMA-co-AA), MMA-AA-BA, CA/PVB blend and CA/poly(MMA-co-AA) blend, were prepared, and their pervaporation properties were evaluated by separation of methanol/C5 or methanol/MTBE (methyl tert-butyl ether). The results shows that the CA composite membrane has a high separation performance (flux Jmenthanol =350g.m-2.h-1 and separation factor a > 400) for methanol/C5 mixtures, and the pervaporation characteristics of MMA-AA-BA copolymer membranes changes with the ratio of copolymer. For CA/poly(MMA-co-AA) blend membrane, the pervaporation performance is improved in comparison with CA or poly(MMA-co-AA) membrane. From the experiment of CA/PVB blend membranes for methanol/MTBE mixture, it is found that the compatibility of blends may affect the separation features of blend membrane.

新型杀虫剂flupyradifurone的合成

Flupyradifurone是由拜耳公司开发的新型杀虫剂。对以丙二酸单甲酯钾盐、2,2-二氟乙胺和2-氯-5-氯甲基吡啶为起始原料,制备flupyradifurone的工艺进行研究,选取了较佳的合成路线。该工艺具有生产成本低、操作简单和易于工业化的特点,对工业化生产具有一定的指导意义。

2-甲基辛酸的合成

在设计合成松树叶蜂性信息素 3,7-二甲基 -2十三醇乙酸酯及丙酸酯的课题中 ,本文首先合成了它的一个重要的结构单元 2 单位基辛酸。以丙二酸二乙酯为原料 ,经己基化、甲基化、水解、脱羧 ,合成了 2 -甲基辛酸 ,总收率为 2 4 2 %。

甲氧羰基乙酸己酯在超临界二氧化碳中溶解行为研究(英文)

设计合成了甲氧羰基乙酸己酯，确定了其结构，在压力为8．5～18．6 MPa，温度为313～353 K测定了其在超临界CO2中的溶解度．并运用Bartle和Chrastil半经验模型对溶解度数据进行关联，由Kumar-Johnston理论计算其在超临界相中的偏摩尔体积．结果表明：甲氧羰基乙酸丁酯在8．5 MPa、313 K下溶解度高达2．62＆#215;10-3 mol/L，与理论计算结果相关性良好，平均相对偏差分别为3．28％～58．65％和0．0068％～27．7％．在313，333，353 K温度下，其偏摩尔体积分别为-5708．79，-1665．36，-707．43 cm3/mol．

2-氯丙酸法制备甲基丙二酸二乙酯

以 2 -氯丙酸为原料 ,经氰化、水解、酯化制得甲基丙二酸二乙酯 ,总收率 41 % .

甲氧酰基乙酸丁酯在超临界CO_2中的溶解度和偏摩尔体积研究

设计合成了非氟亲CO2化合物甲氧酰基乙酸丁酯C8H14O4,利用1H、13C核磁共振和元素分析表征其结构,在不同温度(313,333,353 K)和压力(8.3～12.3 MPa)下测试了其在超临界CO2中的溶解度.并运用Chrastil半经验模型对溶解度数据进行关联,由Kumar-Johnston理论计算了其在超临界相中的偏摩尔体积.结果表明:甲氧酰基乙酸丁酯在8.3MPa、313K下溶解度高达3.73×10-3mol/L,与理论计算结果相关性良好,平均相对偏差为19.13%,在313,333,353K温度下,其偏摩尔体积分别为-6403.82,-626.70,-308.98 cm3/mol.

新型吡唑衍生物1-甲基-4-乙氧羰基-5-羟基吡唑的合成

1-甲基-4-乙氧羰基-5-羟基吡唑是合成吡唑类HPPD酶抑制剂的一种很重要的有机合成中间体。笔者以丙二酸二乙酯与原甲酸三乙酯反应得到乙氧亚甲基丙二酸二乙酯,再与水合甲基肼反应、关环后得到1-甲基-4-乙氧羰基-5-羟基吡唑。探讨了反应温度及溶剂对反应的影响,以水为溶剂,反应温度为回流温度,收率较有机溶剂法有较大幅度提高。

微波辐射法合成丙二酸甲(乙)烷酯

Alkyl methyl(ethyl) malonates were synthesized by solidliquid phase transfer catalysis without solvent in the new method of the reaction of potassium methyl(ethyl) malonate with alkyl bromide or chloride with high yields.Under the microwave irradiation,the reaction time was reduced from 2h to 2min with equal yield.

3-吲哚-甲基-乙酰氨基-丙二酸二乙酯的合成研究

以芦竹碱和乙酰氨基丙二酸二乙酯为原料,合成了3 吲哚 甲基 乙酰氨基 丙二酸二乙酯。着重研究了原料配比,反应温度,反应时间对反应收率的影响,获得了比较理想的合成工艺。即:原料配比(摩尔比)为n(芦竹碱)∶n(乙酰氨基丙二酸二乙酯)=1∶1.1,反应温度为95～100℃,反应时间为8～9h,反应收率为97.0%。

6-甲基-4-羟基-2-吡喃酮的合成

本文报道了以 Meldrum酸为原料经两步合成 6 -甲基 - 4-羟基 - 2 -吡喃酮的方法 :将文献中酸催化关环 。

无溶剂氧化亚锡催化合成2-[(3-吲哚基)-甲基]丙二酸二甲酯衍生物

在氧化亚锡催化下,吲哚、醛和丙二酸二甲酯在无溶剂条件下三组分反应合成了10种2-[（3-吲哚基）-甲基]丙二酸二甲酯衍生物。反应无溶剂污染,反应条件温和,收率为58%-74%。讨论了反应速度与取代基的关系,探讨了可能的缩合反应机理,并应用^1H NMR、^13C NMR、IR等技术手段确定了产品的结构。

绿色有机缓蚀剂的合成及其防腐蚀性能研究

以衣康酸、丙二酸、5-甲基-2-巯基噻二唑为原料经过加成、取代和酰胺化反应,合成了两种新型、高效的环保型水基缓蚀剂,采用红外光谱仪、核磁共振光谱确定其结构,并测试了其防腐蚀性能。结果表明:两种缓蚀剂在腐蚀性介质中对输油管道有很好的防锈抗腐蚀能力,缓蚀剂较佳使用浓度为40μg/g;N,N-二羟乙基-N,N-二羟乙基-(5′-甲基[1,3,4]噻二唑-2′-硫-)-2-甲基丁二酰胺的耐腐蚀性能优于N,N-二羟乙基-(5′-甲基-[1,3,4]噻二唑-2′-硫-)-2-丁酰胺。

5-烃基丙二酸亚异丙酯的Mannich碱与甲基酮的缩合反应

5-烃基丙二酸亚异丙酯的Mannich碱和甲基酮在弱酸如醋酸的存在下,合成得到缩合产物5-(3-氧代烃基)丙二酸亚异丙酯(3).

PCMT1/MST1通路在甲基丙二酸血症脑损伤中的作用

目的:探讨PCMT1/MST1通路在甲基丙二酸血症脑损伤中的作用。方法:培养小鼠皮层神经元,用不同浓度甲基丙二酸诱导小鼠皮层神经元,观察细胞形态变化。采用四甲基偶氮唑蓝(MTT)法检测小鼠皮层神经元活力,Westernblotting法检测各组(甲基丙二酸诱导组、CGP3466B治疗组和对照组)神经元蛋白异天冬氨酸甲基转移酶1(PCMT1)、磷酸化蛋白激酶(MST1)、裂解MST1(cl-MST1)、磷酸化MST1(p-MST1)、Caspase-3、B淋巴细胞瘤-2基因(Bcl-2)、Bcl-2相关X蛋白(Bax)蛋白水平。结果:不同浓度甲基丙二酸诱导24h显示,甲基丙二酸浓度≤8mmol·L^-1时神经元形态无明显变化;甲基丙二酸浓度为12mmol·L^-1时神经元胞内出现空泡,神经元突起缩短,胞体皱缩;甲基丙二酸浓度为16mmol·L^-1时神经元胞体脱落,突起几乎全部断裂。甲基丙二酸组神经元PCMT1、MST1蛋白相对表达量均低于对照组和CGP3466B治疗组(P<0.05),cl-MST1、p-MST1蛋白相对表达量均高于对照组和CGP3466B治疗组(P<0.05)。甲基丙二酸组Caspase-3、Bax蛋白相对表达量均高于对照组和CGP3466B治疗组(P<0.05),Bcl-2蛋白相对表达量均低于对照组和CGP3466B治疗组(P<0.05)。结论:甲基丙二酸可引起皮层神经元凋亡,这可能是通过PCMT1/MST1通路来实现的。

2,2-二甲基丙二酸二甲酯的合成

以丙二酸二甲酯为起始原料,在甲醇钠的作用下与溴甲烷经甲基化反应合成2,2-二甲基丙二酸二甲酯,并对合成工艺进行优化。适宜工艺条件为:n(丙二酸二甲酯)∶n(溴甲烷)∶n(甲醇钠)=1.0∶2.8∶2.8,使用现制的甲醇钠,在回流温度下反应8 h合成2,2-二甲基丙二酸二甲酯,收率90.1%,含量99.3%。