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为了给新型杀菌剂唑菌酯(试验代号:SYP-3343)的环境行为研究提供基本的理化参数,在建立水中微量唑菌酯高效液相色谱(HPLC)测定方法的基础上,本文采用摇瓶法测定了唑菌酯在纯水和缓冲液中的正辛醇.水分配系数。结果表明,水中的唑菌酯经二氯甲烷萃取后进行HPLC测定,HPLC测定条件为:紫外检测波长252nm。甲醇/双重蒸馏水以体积比为94/6混合作为流动相, 相似文献
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椰油醇和正辛醇从水相中萃取螺旋霉素的表观分配系数 总被引:1,自引:0,他引:1
椰油醇和正辛醇从水相中萃取螺旋霉素的表观分配系数陶中东徐志南岑沛霖(浙江大学化学工程系,杭州310027)关键词正辛醇椰油醇螺旋霉素分配系数1前言螺旋霉素(SPM)为大环内酯类抗生素,主要用于抗革兰氏阳性菌感染。经过乙酰化后的乙酰螺旋霉素,是目前市场... 相似文献
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A novel method named two-level group contribution (GC-K) method for the estimation of octanol-water partition coefficient (Kow) of chloride hydrocarbon is presented. The equation includes only normal boiling points and molecular weight of compounds. Group contribution parameters of 12 first-level groups and 7 second-level groups for Kow are obtained by correlating experimental data of three types including 57 compounds. By comparing the estimation results of the first-level with that of the two-level groups, it was observed that the latter is better with the addition of the modification of proximity effects. When compared with Marrero's three-level group contribution approach and atom-fragment contribution method (AFC), the accuracy of the average relative error of GC-K by first-level groups is 7.20% and is preferred to other methods. 相似文献
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研究了衍生脲类除草剂的分子连接性指数(MCI)与正辛醇 水分配系数(Kow)的关系。通过计算14种取代脲类除草剂的MCI并与其logKow进行多元线性回归分析,建立了估算衍生脲类除草剂的Kow的定量模型。计算结果表明零阶指数0Xv是计算衍生脲类除草剂Kow的主要因素,二阶指数2XV是计算Kow值的次要因素。多元线性回归方程的相关系数R=0 8712。平均估算误差S=0 188个对数单位。 相似文献
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研究了发酵初期pH4 0~5 4范围内的调节与设定对赤芝、紫芝、甜芝等3种不同物种灵芝菌体发酵以及主要药用生物活性成分多糖发酵的影响,结果表明:赤芝、紫芝菌体发酵的初始条件以pH4 3最适,而甜芝以pH4 8最适;紫芝胞外多糖发酵在初始条件设为pH5 4时产生最多,而赤芝、甜芝胞外多糖的发酵产量未受初始pH试验范围的影响;赤芝、紫芝在初始pH4 8条件下发酵胞内多糖积累最少,而甜芝此条件下发酵胞内多糖积累最多。讨论认为不同物种灵芝以菌体或者多糖发酵为目标进行优化控制,其发酵初期pH尚需调节到相应的最适设定值。 相似文献
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研究了巴比妥酸类衍生物的分子连接性指数(MCI)和外推至纯水作流动相时的高效液相色谱容量因子(k0)与正辛醇 水分配系数(Kow)的关系。通过13种已知lgKow文献值的巴比妥酸类衍生物的lgKow值分别对MCI计算值和lgk0实验值进行多元线性回归分析,建立了估算巴比妥酸类衍生物的Kow的两种定量模型。用此模型预测了8种巴比妥酸类衍生物的Kow。结果表明两种方法都能较好地预测巴比妥酸类衍生物的Kow。 相似文献
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Sang Hyun Lee Sun Bok Lee 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2009,84(2):202-207
BACKGROUND: Room temperature ionic liquids (ILs) are attractive alternatives to environmentally unfriendly volatile organic solvents. Partitioning is one of the most important and fundamental properties of a chemical, and the octanol/water partition coefficient is widely used to measure the tendency of a chemical to cross biological membranes. However, there is very limited information on the concentration dependence of the partition coefficients of ILs. This study investigated the octanol/water partitioning of 1‐butyl‐3‐methylimidazolium ([bmim]) ILs containing either hexafluorophosphate ([PF6]) or bis[(trifluoromethyl)sulfonyl]amide ([Tf2N]) over a wide range of IL concentrations of three to five orders of magnitude. RESULTS: It was found that the apparent partition coefficients of the ILs increased with increasing IL concentration. A model based on the ionic nature of ILs was proposed to explain this behaviour, and the results showed a good fit with the experimental data. The intrinsic partition coefficients and dissociation constants of the ILs were determined using the equations from the proposed model. The differences in the intrinsic partition parameter values between the two ILs showed a good correlation with other physicochemical properties. CONCLUSIONS: The present study clearly shows that the octanol/water partition coefficients of ILs increase with increasing IL concentration owing to the formation of ion pairs. By using the proposed partition model, it was possible to determine the intrinsic partition coefficients of ILs, and it was found that the apparent partition coefficients of ILs converge to the intrinsic partition coefficients of the ionic species and ion pairs of ILs with decreasing and increasing IL concentration respectively. Copyright © 2008 Society of Chemical Industry 相似文献
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It has been pointed out previously that the butane/water partition coefficient is a key parameter in the determination of extraction affinity. We have taken 43 such partition coefficients and have obtained a very satisfactory correlation with Abraham solvation parameters. Similarly, we have obtained a good correlation of 43 gas/butane partition coefficients. These correlations are general, and can be used to predict further values of the butane/water and gas/butane partition coefficient. 相似文献
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相转移催化氧化法合成苯甲酸 总被引:1,自引:0,他引:1
以相转移催化氧化法合成苯甲酸,结果表明在酸性介质中以苯作溶剂,反应时间缩短2~3h,产率提高15%以上,MnO2沉淀减少25%。达到了缩短反应时间、提高产率和减少MnO2沉淀的目的。 相似文献
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在盐酸存在下,以邻氨基苯甲酸(OABA)和双氰胺(DCDA)为原料,通过"一锅法"直接制备了邻双胍基苯甲酸盐酸盐(o-BGBAH);探讨了反应温度、反应时间、盐酸与双氰胺的物料比及双氰胺与邻氨基苯甲酸的物料比等对产物收率的影响;用FT IR、1 H NMR和UV等方法表征了产物结构,HPLC分析了产物中o-BGBAH的含量。结果表明,盐酸与双氰胺的摩尔比为1.40、双氰胺与邻氨基苯甲酸的摩尔比为2.0、反应温度为60℃、反应时间为6.0h时,产品收率约为86.7%;HPLC的分析结果表明产品中邻双胍基苯甲酸盐酸盐含量超过96%。 相似文献
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介绍了结晶法精制苯甲酸的三种工艺—升华结晶 ,溶液结晶 ,熔融结晶。重点评述了熔融结晶法的装置与应用现状 ,同时展望了苯甲酸精制的未来发展动向 相似文献