加压溶剂法提取雷公藤甲素及其条件优化

以雷公藤为原料,采用加压溶剂法提取雷公藤甲素,以1,2-二氯乙烷为溶剂,考察了提取时间、料液比和提取温度等因素对提取工艺的影响,并在单因素试验基础上,根据中心组合试验设计原理采用三因素三水平的响应面分析法进行工艺优化,得到提取过程优化的工艺条件为:料液比1:9.7,提取温度115℃,提取时间80min,雷公藤甲素的实际得率可达0.173‰,纯度为1.21%,与常规回流提取法相比优势明显。     

Using membrane-supported liquid-liquid extraction for the measurement of extraction kinetics

Membrane-supported liquid-liquid extraction uses artificial membranes for the generation of a phase interface between the two liquid phases involved in extraction. Additional equipment for the generation of droplets as well as phase separation afterwards is no longer necessary. Since the membranes used for this special type of extraction are quite well described concerning thickness, porosity, tortuosity and material it is possible to generate information about the diffusion coefficient of the component to be extracted within the preferred solvent from extraction trails easily. This article describes an experimental set-up for both the proof of principle of membrane-supported liquid-liquid extraction and, using a dedicated computer-aided data treatment, how to calculate the overall mass transfer coefficient as well as the diffusion coefficient for a given system within moderate testing duration.     

Comparative study of the extraction methods for recovery of carotenoids from algae: extraction kinetics and effect of different extraction parameters

Carotenoid extraction from algae is currently under intensive research due to the increased demand for naturally occurring compounds, which are especially rich in biologically active isomers. Furthermore, natural carotenoids exhibit greater stability than synthetic ones. Conventional liquid extraction suffers from several drawbacks, such as use of high amounts of solvent, and several extraction steps. In this work carotenoid extraction from algae using different methods, such as microwave and ultrasound assisted extraction as well as pressurized liquid extraction and extraction with supercritical CO₂ and ethane, is summarized together with modelling of extraction kinetics. In addition carotenoid availability, algae pretreatment, stability of extracts, their antioxidative and antimicrobial activities as well as downstream processing and storage of algae extracts have been reviewed. As a conclusion it can be stated that carotenoid extraction is complex, demanding optimization of the carotenoid yield and antioxidative stability, which are often inversely proportional. © 2014 Society of Chemical Industry     

典型有机磷类萃取剂在溶剂萃取中协同萃取的研究进展

协同萃取作为溶剂萃取法的分支被广泛研究。对于协同萃取的机理探索,必须阐明协同效应产生的微观原因,并给出微观与宏观性质的联系,因此从分子的微观结构和内部运动认识协同萃取以及影响因素尤为重要。本工作重点综述了萃取剂之间、萃取剂与金属离子之间的协同作用机理以及影响其作用因素的研究进展,指出协同萃取的本质是氢键的形成导致萃取剂的结构与能量发生变化,进而提高了萃取效果。协同萃取主要包括两个方面,一是更容易生成稳定的萃合物从而提高萃取效率,二是利用萃取剂之间的差异提高分离性能。萃取系统的pH、不同萃取剂的组合及比例、萃取剂的浓度、中性磷类萃取剂的添加等诸多因素显著影响协同萃取过程,且各种因素之间存在交互。运用模拟计算进行理论性预测,通过实验进行验证,并且辅以现代分析化学方法进行表征,是今后化工研究领域行之有效的方法之一,理论推广实际,从而更好地指导生产。     

Mechanical extraction

The mechanical screw press was the principal means of extracting vegetable oilseeds in the United States from the 1930s through the 1940s and 1950s. Then the utilization of solvent extraction cut drastically into their use for full extraction, but created a great demand for screw presses for prepressing of high oil content seeds for solvent extraction. However, use of the screw press for full extraction has been increasing over the years in the less developed countries, and is the main modern machine utilized for some products such as palm fruit. Today ever larger and more efficient machines are being developed for full extraction and pre-pressing of vegetable oilseeds and fruits.     

微波条件下氯化锌对乙醇抽提神府煤的影响

微波条件下,研究了在乙醇抽提神府煤中加入氯化锌对其结果的影响。采用气相色谱/质谱联用的方法分析了乙醇和乙醇-氯化锌抽提物的组成;利用傅里叶红外光谱技术分析了神府脱矿物质煤、乙醇抽余煤和乙醇-氯化锌抽余煤的结构。分析结果显示:在乙醇溶剂中添加少量的氯化锌,其抽提物的组成发生了改变;乙醇-氯化锌抽余煤与原脱矿物质煤和乙醇抽余煤相比,芳环吸收强度降低,表明在抽提过程中可能伴随着烷基化反应的发生。     

液-液萃取及新型液-液-液三相萃取机理研究进展

根据新型液-液-液三相体系的特点,对传统两相溶剂萃取、双水相萃取机理研究进展进行了综述,提出应用Lewis酸碱理论对两种萃取体系的萃取机理分别进行归类,评述了新型液-液-液三相体系研究进展并对其研究方向进行了展望。     

微波萃取技术研究进展

综述了微波萃取的机理、特点、参数和设备、影响微波萃取效果的因素,介绍了微波萃取技术在有效成分提取、临床和物质检测方面的国内外研究和应用情况。微波萃取作为一种新技术,其前景广阔,有望在萃取抽提领域开拓出新的天地。     

微波浸提法脱除聚氨酯合成革中微量N,N-二甲基甲酰胺的研究

采用微波辅助浸提法脱除聚氨酯合成革中微量N,N-二甲基甲酰胺(DMF),研究了浸提时间、微波功率、浸提温度和液固比对DMF脱除率的影响。结果表明,在浸提时间15 min,微波功率700 W,浸提温度80℃,液固比55∶1条件下,聚氨酯合成革中DMF含量为23 mg/kg,脱除率达98.8%。     

Rapid extraction of canola oil

The simultaneous size reduction and solvent extraction of canola seeds were studied using a laboratory blender and a small, pilot-scale Szego mill. The laboratory tests established that over 95% of the oil may be removed from the seed in a single contact stage. The effects of contact time and solvent-to-seed ratio were investigated. The extraction equilibrium favored the extraction of the oil at higher solvent-to-seed ratios. In all cases the extraction reached some 90% of the equilibrium value after 3 min. Runs in the Szego mill, which is a unique orbitalmill developed by one of us (O. Trass), confirmed that solvent grinding is an efficient extraction technique. In this equipment, contact times as short as 30 sec give significant extraction, with the system approaching equilibrium in one minute. The Szego mill appears to be suitable for the rapid extraction of edible oil seeds such as rapeseed.     

Solvent extraction of soybeans

The removal of edible oils from oilseeds was practiced by the Egyptians many centuries ago. Some of the developments leading to today’s worldwide extraction industry are discussed, and a brief history of the industry in the United States from 1940 to the present is included. The theory of solvent extraction is outlined in practical terms. Several types of solvent extraction and desolventizing systems are explained. Also, typical preparation and extraction processes for presscake, soybeans, and some high oil content seeds are illustrated. Some reasons for taking extra precautions in the preparation process and the desolventizing process when producing human edible soy protein products are explained. Energy conservation suggestions are included.     

蛇床子中蛇床子素的提取工艺研究

采用乙醇加热回流法提取蛇床子中的蛇床子素,对提取工艺进行优化。结果表明,最佳工艺条件为:提取液为75%乙醇溶液,用量为药材的8倍,提取时间为1.5 h和提取温度为80℃。     

十溴联苯醚萃取条件优化研究

针对十溴联苯醚(BDE-209)难溶性和萃取方法的复杂性,通过从萃取剂和萃取条件上对BDE-209进行萃取优化。结果表明:(1)上清-沉淀复合法的萃取效率仅为21.8%。(2)烘干温度对样品的萃取效率影响不显著,在80、 100和120℃条件下的萃取效率均达到95%以上,但高温条件有可能使BDE-209发生降解。(3)不同萃取剂和分步萃取对样品萃取效率影响显著,2次萃取比一次性萃取的萃取效率提高了13.6%~29.6%,正己烷萃取效率(100%)>乙酸乙酯萃取效率(84.87%)>异辛烷萃取效率(23.33%)。(4)采用正己烷少量多次萃取,可短时间内最大程度回收水相样品中的BDE-209(97.82%)。少量多次萃取法萃取效率高,操作简便,节省时间,适于大部分水相样品快速定量分析。     

溶剂萃取新技术述评

本文就溶剂萃取技术的新进展作一评述,介绍了近年来发展的几种淀粉地取新技术：超临界流体萃取、反胶团萃了 波萃取、微波萃取、电泳萃,磁场协助萃取、等。     

淫羊藿超声提取工艺优化

目的:优选淫羊藿的超声提取工艺。方法:以淫羊藿苷的提取率为指标,高效液相色谱检测含量,应用正交试验优化淫羊藿的最佳超声提取工艺条件。结果:影响提取的主次因素为ABDC(A:乙醇浓度;B:物料比;C:提取温度;D:提取时间)。最佳提取条件为:超声功率为300W、60%乙醇溶液、液固比25:1、提取时间60min、提取温度50℃。根据优选工艺验证实验表明,有效成分提取率94.88%,重现性较好。结论:优选得到的工艺稳定可行。     

溶剂流动方式对药物提取过程的影响

以大黄为实验材料 ,利用半连续提取设备 ,分别采用简单提取和循环提取的方式 ,研究了溶剂流速对提取率和提取液浓度的影响。结果表明简单提取的速度快 ,极限提取率高 ,提取液浓度在初期很高 ,并随提取率增加而下降 ;循环提取溶剂用量和提取液浓度易控制 ,收率受级平衡限制而较低 ;适当增大溶剂流速可缩短提取时间 ,但会增加前者的溶剂消耗 ;在简单提取中引入回流对后期的提取有一定促进作用 ,回流的时间和回流强度值得研究。将简单提取和循环提取适当组合能够在保证效率的基础上使收率和提取液浓度有较大提高。     

酶法提取无患子皂苷的工艺研究

采用酶法提取无患子皂苷,研究了酶的类型对无患子皂苷提取的影响,并通过正交实验优化酶法提取工艺。结果表明,纤维素酶有助于无患子皂苷的提取,酶提法的较优工艺条件为:纤维素酶用量为无患子粉末质量的0.1%,酶提时间2.5 h,酶提温度50℃,pH值4.7。此时,无患子皂苷的提取率达到86.59%,比未加酶处理时提高了19.63%。     

Solvent extraction of oil from soybean flour I— extraction rate,a countercurrent extraction system,and oil quality

Measurements of rates of oil extraction from either fine flour or soybean flakes in a column showed that oil extraction from flour was dependent on the volume of solvent, but oil extraction from flakes depended on time of contact rather than volume of solvent. We interpreted the data to mean that oil was being washed out of the fine flour with little diffusion involved, whereas in flakes, the limit on rate was diffusion of the solvent into and out of the tissue. Fine full fat flour worked well in a batchwise countercurrent extraction system with mixing and centrifugal separation. Because the oil dissolved immediately and reached equilibrium rapidly, the actual material balance was close to calculated values. However, due to the large hold-up volume, the separation of miscella from the meal required several mixing and separation stages. The oil resulting from this countercurrent extraction system had a superior quality with 37 ppm phosphorus, 0.08% free fatty acids, and a light color.     

Mechanical oil extraction

Competitive pieces of equipment for full-pressing and prepressing oilseeds are described. “Enhanser” machines to treat seeds before solvent extraction considerably increase the capacity of the solvent extraction system.     

Solvent extraction of cottonseed meats

In the experimental countercurrent extraction of flaked cottonseed meats by trichloroethylene the residual oil content of the extracted flakes decreased with: first, a decrease in the final oil content of the final miscella; second, decrease in the flake moisture down to 8.64%; third, decrease in flake thickness; fourth, increase in temperature; and fifth, increase in extraction time. For the batch of cottonseed meats used the following equation was developed: whereR is percent residual extractables,b is flake thickness in feet,D is meat diameter in feet,ϑ is extraction time in hours,μ in viscosity, lb. per ft. hr.,ρ is density, lb. per cu. ft., andt is extraction temperature in degrees F. Not enough data were secured by extraction with hexane to check the equation developed for trichloroethylene extraction. Hexane is a poorer solvent for cottonseed oil than trichloroethylene. The amount of oil remaining in the meal is affected to a greater extent by the miscella concentration in hexane extraction than in trichloroethylene extraction.