大孔吸附树脂精制鱼腥草黄酮类化合物

Flavonoids are one main kind of effective components in Houttuynia cordata Thunb., which display a wide range of pharmacological activity. In this study supercritical fluid extraction （SFE） with carbon dioxide was first used as preparat ion step to remove the volatile components, which are also active components, from Hout-tuynia cordata Thunb. Then ultrasound-assisted extraction was used to obtain the crude flavonoids and the macro-porous resin adsorption technology was further employed to purify the flavonoids. Nine kinds of macroporous resins with different properties were tested through static adsorption, and one macroporous resin labeled as D101 was selected. The effect of several factors, such as the ratio of column height to diameter, initial concentration and pH, on both flavonoids yield and content were explored by dynamic adsorption to obtain reasonable conditions of adsorption and desorption. The experimental results show that the content of fiavonoids can be above 60% with fia- vonoids recovery of 93.3 % under the optimum conditions of purification. HPLC analysis of the final flavonoids product shows it contains quercitrin, hypefin, rutin and quercetin.     

膨润土／活性炭复合吸附剂对土霉素的吸附性能研究

研究了一定条件下低品位钙基膨润土／活性炭复合吸附剂对土霉素废水的吸附作用。结果表明：活化温度在140℃、pH=6.5时复合吸附剂对土霉素最大吸附容量为21．78mg／g，明显大于原土的14．16mg／g，讨论并合理地解释了影响吸附的因素，适宜条件下对吸附剂多次再生，最大吸附容量仍可达到21mg／g以上。     

丙酮酸镁合成工艺的研究

研究了丙酮酸与碳酸镁反应合成丙酮酸镁的工艺过程.通过考察不同的原料配比、反应温度、反应时间以及终点控制,确定了最佳的合成条件:n(丙酮酸):n(碳酸镁)=2.1:1,在温度为65℃下反应60min,反应终点pH在4左右;在此条件下,丙酮酸镁的收率可达94.4%.     

丙酮酸改性壳聚糖对金属离子的吸附性能研究

丙酮酸经Schiff碱反应对壳聚糖进行修饰 ,合成了高取代的水溶性丙酮酸缩壳聚糖 (PCTS) ,研究了PCTS、SCTS(水杨醛改性壳聚糖 )、CTS(壳聚糖 )对Cu(Ⅱ )、Zn(Ⅱ )、Co(Ⅱ )的静态吸附性能 ,并采用正交实验法考察了金属离子浓度、介质酸度、吸附量和吸附时间对吸附剂去除金属离子能力的影响。结果表明 ,PCTS的吸附性能优于SCTS与CTS ,对Cu(Ⅱ )、Zn(Ⅱ )、Co(Ⅱ )的吸附容量 (pH =7 0 )分别为 2 79 56、1 96 63、70 2 1mg/g ,金属离子浓度、介质酸度对吸附性能影响大 ,而吸附剂用量、吸附时间对吸附性能影响较小。     

溴代丙酮酸的合成研究

本文对丙酮酸的溴代反应进行了探讨,选择不同的条件,比较其对反应速度和产物的产率影响,从而找到最佳实验方案,得到超过文献值的最好收率96％～98％。     

乳酸催化转化丙酮酸溶液中乳酸与丙酮酸络合萃取分离技术研究

以乳酸为原料,研究了催化转化丙酮酸技术。通过诱变筛选出性能优良的产酶菌株,选择合适的方法将细胞固定,进行乳酸的生物催化。再利用化学催化的方法将未被生物转化的乳酸转化为丙酮酸,反应液为混合液,未反应完全的乳酸和丙酮酸的分离成为技术的关键。本文主要介绍了络合萃取技术实现丙酮酸和乳酸的分离中试技术研究。     

水溶性丙酮酸锌的合成工艺研究

采用丙酮酸与乙酸锌反应合成水溶性丙酮酸锌,确定了适宜的工艺条件。合成水溶性丙酮酸锌最佳的反应条件是:以乙酸乙酯和丙酸为溶剂,其体积比为1∶0.7,丙酮酸与乙酸锌摩尔配比为1∶0.55,在20~25℃温度下反应。得到的产品的结构经红外和核磁的确证,其结构式为(CH3COCOO)2Zn.1/2H2O,得到的产品在水中具有较好的溶解性。     

丙酮酸甲酯的合成

本文介绍了以丙酮酸和无水甲醇为原料,加入合适的催化剂合成丙酮酸甲酯的过程。通过对反应物配比、带水剂、反应时间等影响因素进行对比试验,确定以四氯化碳为带水剂,最佳反应配比为:丙酮酸∶无水甲醇∶四氯化碳=1∶2.5∶0.28,产物收率可达73.9%。该工艺过程简单,易操作,适合工业化大生产。     

乳酸合成丙酮酸的研究

介绍了由乳酸制备丙酮酸的各种催化工艺方法 ,并对其产率、前景、优缺点等进行了简单的评述     

弱碱性树脂处理β-萘磺酸废水的吸附分离热力学性能

研究了β-萘磺酸废水中β-萘磺酸、H₂SO₄、H₂SO₃ 单组分吸附平衡,并以Langmuir、Freundlich模型对其进行模拟.吸附过程的热力学计算及分析结果表明,吸附过程为放热的化学吸附过程,吸附量顺序为H₂SO₄>NSA>H₂SO₃,推动力大小顺序为H₂SO₄>NSA>H₂SO₃,吸附过程熵增加.以D301R弱碱性树脂为吸附剂,可有效地实现三者的分离.     

Recovery of pyruvic acid with weakly basic polymeric sorbents

BACKGROUND: Carboxylic acids are among the most important substances that can be manufactured from biomass. However, the recovery of carboxylic acids from fermentation broths presents a challenging separation problem. To avoid the production of waste salts and net consumption of chemicals in the calcium carboxylate salt process, the use of reversible chemical complexation with polymeric sorbents and extractants is attractive for carboxylic acid recovery. Pyruvic acid is widely used in the manufacture of medicines, pesticides and foodstuffs and can be produced by fermentation. Since the acidity of pyruvic acid (pK_a = 2.49) is stronger than that of normal carboxylic acids, and as few reports on the recovery of pyruvic acid are available, the sorption of pyruvic acid from aqueous solution on two types of weakly basic polymeric sorbent, tertiary amine D301R and primary amine D392, was investigated over a wide pH range and at various salt (MgSO₄) concentrations. RESULTS: Overloading adsorption of pyruvic acid on both weakly basic polymeric sorbents occurred, with the overloading of D392 being greater than that of D301R. The adsorption of pyruvic acid on both sorbents was greatly affected by the solution pH and the salt concentration in the aqueous phase. An overloading model was able to predict the experimental uptake data very well. CONCLUSION: Solution pH is one of the most important operating conditions, and both polymeric sorbents D392 and D301R can be used to recover pyruvic acid from dilute aqueous solution with high efficiency at a solution pH around 2. The uptake by D392 is greater than that by D301R owing to steric hindrance of the tertiary amine. Copyright © 2008 Society of Chemical Industry     

2-萘磺酸/硫酸在弱碱性树脂上的吸附平衡研究

Experiments for single and bisolute competitive adsorption were carried out to investigate the adsorption behavior of β-naphthalenesulfonic acid(NSA and sulfuric acid from their solution at 25℃ onto weakly basic resin D301R,Adsorption affinity of sulfuric acid on D301R was found to be much higher than that of NSA.The data of single-solute adsorption were fitted to the Langmuir model and the Freundlich adsorption model.The ideal adsorbed solution theory(IAST) coupled with the single-solute adsorption models were used to predict the bisolute competitive adsorption equilibria.The IAST coupled with the Langmuir and the Freundlich model for sulfuric acid and NSA.Respectively,yields the favorable representation of the bisolute competitive adsorption behavior.     

乳酸氧气氧化法制备丙酮酸

丙酮酸是一种重要的有机合成和药物合成中间体 ,研究了以乳酸为原料 ,氧气催化氧化合成丙酮酸 ,并探讨了催化剂组成、用量、氧气用量、温度、反应时间等因素对合成反应的影响 ,确定了最佳合成条件 ,其条件为以 Pt/Pb( NO3) 2 /C为催化剂 ,其组成比为 3%∶ 5 %∶ 92 %(质量比 ) ,Pt用量为 0 .1 5 g(铂与乳酸的摩尔比为 1 .92× 1 0 -3) ,O2 加入量为 2 .33L/h(空气为 1 1 .1 L/h) ,在 45°C下反应 2 h时 ,收率为 66.0 %     

丙酮酸的合成研究进展

丙酮酸作为一种重要的有机化工产品，日益广泛地应用于医药、农药、日化和食品等行业。本文从化学合成法和生物技术法两个方面，详细介绍了丙酮酸合成现状及其研究进展，并对丙酮酸的发展前景进行了展望。通过对上述两种方法优缺点的比较，指出生物技术法具有原料成本低、产物纯度高、反应条件温和等优点，具有良好的发展前景。     

丙酮酸的发酵代谢机理研究

近年来,丙酮酸广泛用于医药、化工、保健品等行业中,应用领域不断扩大,世界上需求量不断增长。发酵法生产丙酮酸由于具有成本低廉、产品纯度高、反应条件温和、对环境友好而得到发展。论述了代谢分析在丙酮酸发酵中的应用,包括乙酸渗漏菌株的筛选、能量代谢调控等,同时指出了今后的研究方向。     

我国丙酮酸及系列产品合成工艺10 a进展

综述了丙酮酸及系列产品近10 a来合成工艺的发展状况。介绍了目前国内生产丙酮酸的各种合成工艺方法,包括酒石酸法、乳酸氧化法、直接发酵法和酶催化法,阐述了它们的合成反应原理、工艺参数、产率等,评价了这些方法的利弊与发展前景。     

D354大孔弱碱树脂吸附游离酸的行为研究

利用电导实验技术,跟踪观察D354大孔弱碱离子交换树脂吸附游离酸的行为。利用固—液界面吸附的动力学方程,求取吸附过程吸附质亲和能。讨论酸的浓度和树脂类型对吸附行为的影响。     

间接电催化氧化法合成丙酮酸

采用电位扫描和旋转电极等方法对酸性介质中Ｂｒ－间接电催化乳酸合成丙酮酸的机理进行了研究，证实随后的化学反应为速度控制步骤，其反应的速率常数为３．２ｍｏｌ·Ｌ·ｓ－１。对电极材料、电流密度、溶液组成等影响因素的研究表明：铂电极较ＤＳＡ具有更好的催化活性，当电流密度为１２．５ｍＡ·ｃｍ－２，乳酸与溴化钾的摩尔比为５∶１时，得到的电流效率较高     

丙酮酸化学萃取的盐效应

以三辛胺为萃取剂,在不同离子类型及离子强度下对丙酮酸的络合萃取过程进行了研究。结果表明,在一定pH范围内,随无机离子浓度的增加,丙酮酸分配系数随盐浓度的增加而迅速降低;萃后水相pH随盐浓度的增加均有不同程度的升高,在同一离子强度下,萃取剂浓度越高,萃后水相pH上升幅度越大。红外光谱的分析结果证实了无机阴离子可能通过同离子竞争,抑制了丙酮酸根离子与络合剂的离子对缔合作用,从而降低了萃取效果。