Microwave-assisted solvent extraction of castor oil from castor seeds

This study was aimed at evaluating the physicochemical properties and oxidation stability of castor oil using microwave-assisted solvent extraction (MAE). MAE was performed using 5% ethanol in hexane as solvent at different extraction times, power intensities and solvent-to-feed (S/F, ml of solvent to gram of feed) ratios. The process parameters were optimized by statistical approach using historical data design of response surface method (RSM). The oils were characterized for yield, physicochemical properties, dielectric properties and oxidation stability, and comparison was also made with oil extracted using Soxhlet method. Results show that the maximum oil yield of 37% was obtained at 20 min with microwave power intensity of 330 W and S/F ratio of 20. The main fatty acid composition of castor oil is ricinoleic acid. The density, refractive index, dielectric properties and oxidation stability of oils are not affected by the extraction methods and extraction parameters of MAE. However, the MAE-extracted oil is more viscous compared to that by Soxhlet method. With extra caution on oil oxidation, MAE could be a promising solvent extraction method with an 86% less in processing time and a higher yield.     

Rapid extraction of products from coal hydrogenation reactions using an ultrasonic bath

Extraction of products into dichloromethane solution from reactions of Victorian brown coals with hydrogen in tetralin can be achieved in 2 min by immersing the extraction mixture in an ultrasonic bath at ambient temperature. The same levels of extraction using the Soxhlet technique can only be achieved by prolonged periods of extraction during which the coal extracts are heated at the reflux temperature of the solvent.     

The extraction of natural cashew nut-shell liquid from the cashew nut (Anacardium occidentale)

In the two-stage recovery of natural cashew nut-shell liquid (CNSL) by solvent extraction, the overall yields from half-shells obtained by mechanical cutting and from chilled fragmented shells (to solidify the phenols) by manual processing are identical, indicating that no physical loss of phenolic material occurs in the mechanical process. At the first stage, prior to comminution, the yield from intact half-shells of mechanical origin is considerably less than that from manually processed shells due to extensive internal fracturing of the shell structure and greater solvent penetration in the latter case. Static solvent extraction of macerated shells gave the same yield as Soxhlet extraction, but the filtration stage was difficult and large volumes of solvent were required. Soxhlet solvent extraction or ultrasound/solvent extraction of manually processed shells at ambient temperature gave similar yields and economy in solvent usage. Both were much superior to mechanical agitation. By catalyzed decarboxylation of the recovered natural CNSL an almost theoretical yield (25%) of phenolic lipid rich in cardanol was obtained, which is considerably higher than that (10%) in the traditional recovery of technical CNSL by the hot oil bath industrial method. Natural CNSL contains a predominant amount of anacardic acid and represents a novel phenolic lipid source. Chemical reduction with air/aqueous hydrazine gave saturated natural CNSL. Polymerization of natural CNSL was effected in alkaline solution with paraformaldehyde. Part 27. Part 26, ref. 1.     

正交实验优化异甘草素超声提取工艺

采用超声法提取乌拉尔甘草中异甘草素,通过乙醇体积分数、液固质量体积比(g/mL)、超声提取时间和提取次数4个因素对异甘草素提取率的影响进行了正交实验,确定超声提取最佳工艺条件为:体积分数80%乙醇,液固质量体积比(g/mL)10∶1,超声20 m in,提取3次,异甘草素的提取率为0.37‰,是乙醇热回流提取的2.06倍,是索氏提取的1.54倍。超声提取浸膏中异甘草素的质量分数为0.55%,是乙醇热回流提取的3.24倍,是索氏提取的1.45倍。结果表明:超声提取甘草中异甘草素具有提取温度低、速度快、提取率高、纯度高等特点。     

正交设计法优选杜鹃花中总黄酮的提取工艺

为确定提取杜鹃花中总黄酮的最佳工艺条件。以用分光光度法测定得到的总黄酮含量为指标,采用正交试验设计,分别考察乙醇冷浸、回流和超声提取对提取率的影响,并与乙醇索氏提取法比较。结果得到在不同的乙醇提取工艺中,总黄酮含量高低顺序为回流法≈索氏提取法〉超声法≈冷浸法。由此知提取杜鹃花总黄酮的最佳工艺条件为11倍量60％乙醇,水浴回流提取2次,每次1．5h。     

超声辅助萃取沙棘黄酮工艺研究

探索超声波萃取法浸提沙棘黄酮最优工艺条件;通过单因素和正交实验法与微波法、索氏浸提法作了对比研究;超声萃取法优化条件为:浸提温度为60℃,功率70W,时间45min,固液比1∶10为佳,在最优条件下浸提沙棘叶中的黄酮,两种方法的产量分别为:超声波3.867mg/g,索氏浸提法3.697mg/g;电磁强化分离沙棘黄酮具有产量高、省时、溶剂用量少、耗能低等优点。     

溶剂和提取方法对苍耳子油提取的影响(英文)

为了有效提高苍耳子油的提取效率,考察了提取溶剂和提取方法对其提取率的影响.在5种常用提取溶剂(乙醇、乙酸乙酯、丙酮、二氯甲烷和环己烷)中,采用索氏提取法时二氯甲烷的提取率最高,采用微波法时乙醇的提取率最高.另外,采用微波法提取的苍耳子油的得率略低于索氏提取法,但微波法的提取效率更高,提取时间节省近30倍,溶剂消耗节省2倍.综合考虑,微波法提取具有更大的优势.     

儿童胶画颜料中邻苯二甲酸酯类化合物检测前处理方法的研究

考察了12种不同种类的溶剂对儿童胶画颜料中邻苯二甲酸酯类化合物萃取效率的影响,发现乙酸乙酯作为溶剂时,萃取效率最高.比较了微波萃取、索氏提取、超声萃取、快速溶剂萃取这4种前处理方法对萃取效率的影响,发现微波萃取效率最高.进一步优化了微波萃取的方法,萃取效率随着微波萃取温度的升高而提高.但是,当萃取温度从100 ℃提高到120℃时,萃取结果增加不明显,说明在100℃时,萃取已经相对完全.该前处理方法简单快速、提取效率高、使用的试剂毒性小、对环境友好,能够满足儿童胶画颜料中邻苯二甲酸酯类化合物的检测要求.     

超声波作用下溶剂萃取法分离镧铈元素

针对溶剂萃取法分离稀土元素的工艺中采用氨水为皂化剂造成排放的废水中氨氮含量超标,采用氢氧化钠为皂化剂使得排放废水中钠盐含量超标而造成环境污染的问题,研究了以未皂化的P204为萃取剂,超声波作用下镧铈元素萃取分离的方法。考察了料液酸度、超声波强度、超声波频率分别对镧铈分配比、分离系数及饱和萃取容量的影响。结果表明：当超声波强度为20 W/cm2、超声波频率为30 kHz、料液酸度为5时,镧铈元素的分配比、饱和萃取容量和元素间的分离系数达到最大,其中饱和萃取容量分别为35 g/L和19 g/L,镧铈间的分离系数最大为4.63。通过红外光谱检测可知溶剂萃取法分离镧铈元素时,由于超声波的作用使得萃取剂P204二聚体中的氢键部分断裂,因此有更多的单体P204能够与稀土离子发生萃取反应,所以超声波作用下镧铈的饱和萃取容量和分配比均大于无超声波作用。     

微波-超声波协同萃取银杏黄酮的工艺研究

以银杏叶为材料,研究了乙醇浓度、微波功率、微波处理时间、料液比、银杏叶粉碎颗粒大小以及微波-超声波协同作用对银杏黄酮提取效率的影响。结果表明微波处理,微波-超声波协同处理可以显著提高银杏黄酮的提取率。确定了最佳的微波处理条件:70%乙醇为萃取液,料液比1∶20,粉末颗粒80目,微波功率50W,微波处理时间4 m in,处理后水浴回流提取2 h所得提取液的黄酮提取率达到81.76%,比直接水浴提取提高了1.3倍,微波-超声波协同处理的黄酮提取率达到83.54%。     

油污土壤中石油烃含量测定方法探究

为了解油污土壤中石油烃含量测量方法应用效果,分别用微波萃取、索氏萃取、超声萃取、快速溶剂萃取法,对污染样中石油烃类物质进行了萃取措施。并利用红外分光光度法,对石油及副产品污染土壤中石油烃含量进行了测试。得出快速萃取——红外分光光度法萃取率较高,且萃取剂用量少。可以为石油及其副产物污染土壤中石油烃含量的高效、精确测定提供依据。     

超声波辅助混合溶剂提取蚕沙中叶绿素的工艺研究

以石油醚-丙酮混合溶剂为提取剂,采用超声波辅助法提取蚕沙中叶绿素,以叶绿素提取率为目标,对超声时间、超声温度、超声功率、固液比、助剂(丙酮)含量和提取次数进行优选研究。结果表明,最佳提取工艺为提取次数4次,助剂(丙酮)含量20%,固液比1∶4(g/mL),超声时间50 min,超声功率90 W,超声温度45℃。在此优化条件下,蚕沙中叶绿素提取率为90.6%。     

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。     

Diffusion of solvent from a cast cellulose acetate solution during the formation of skinned membranes

The transport of solvent out of a cast cellulose acetate (CA) solution into the coagulation bath during membrane formation is treated as a diffusion process. From the increase of solvent concentration in the bath with time (solvent leaching experiments) an overall solvent diffusion coefficient has been calculated. In size these coefficients compare well to mutual pseudo-binary solvent-non-solvent diffusion coefficients determined by means of a classical boundary broadening method applied to ternary solutions with fixed CA concentration, but with a gradient in solvent-nonsolvent composition. Since binary polymer-solvent interdiffusion coefficients are at least one order of magnitude lower, it is concluded that the diffusion of solvent into the coagulation bath is essentially a pseudo-binary solvent-non-solvent diffusion process. Combination of experimental results with model calculations for the effect of a thin dense skin on the diffusion of solvent out of the sublayer shows that the casting-leaching diffusion coefficient can be used to describe the out-diffusion of solvent from the layer under the skin provided that the relative skin resistance is not too high, or that the skin thickness is small.     

A solvent extractor system for the rapid extraction of lipids and trace bioactive micronutrients in oilseeds

A low-cost laboratory extractor has been designed and constructed that selectively extracts polar and nonpolar components from oilseeds and other matrices. The extractor uses available high-performance liquid chromatography laboratory equipment for pumping the solvent into the extractor. Pressure, temperature, and valving arrangements are automatically controlled by commercially available components. Advantages of this system include low initial investment, reduced solvent consumption, shorter extraction times, quantitative lipid recovery, use of multiple extraction solvents, and reduction in cost per sample. The method has broader applications that include extraction of trace components from a variety of matrices, for example, the extraction of pesticides from foods and polychlorobiphenyls from soil. Class separation of components from different matrices can be achieved easily by selection of solvents with the appropriate polarity characteristics. Very small samples can be extracted simply by changing cell size or by adding an inert material to the cell to fill the void volume. Analyte collection can be accomplished by collecting in a test tube with an appropriate solvent, or on a solid-phase material. Optimization of extraction times, number of extractions, matrices, and solvent used is described. Neutral lipids were extracted from peanut meal in 70 min by the rapid extraction method compared to 1440 min required to extract the comparable amount of neutral lipids from a similar sample by the Soxhlet extraction method.     

Extraktion mit überkritischen Fluiden,mikrowellenunterstützte und Soxhlet-Extraktion zur Probenvorbereitung von Boden und Klärschlamm für die gaschromatographische Analytik der PCB

Supercritical Fluid Extraction, Microwave Assisted Extraction and Soxhlet Extraction for the Analysis of PCB's in Soil and Sewage Sludge The supercritical fluid extraction (SFE) was applied on the analysis of PCB's in soil and sewage sludge. Some questions concerning the performance of SFE were studied. With spiked samples and the modifier toluene put directly onto the sample the effect of a static extraction before the dynamic extraction step is described. It was found that matrices with a high content of total organic carbon show matrix effects in SFE, which was identified by calibration of the whole analytical process and eliminated by repeating the extraction. Two real samples were used to compare the SFE with soxhlet extraction and organic solvent extraction by means of microwave energy. The extracts were cleaned by column chromatography on aluminium oxide and silica gel modified with silver nitrate and afterwards analysed by GC-ECD and GC-MS (SIM mode). Soxhlet and SFE gave comparable results. The best extraction results were achieved by microwave assisted extraction with a solvent mixture of hexane/acetone 3:1.     

A rapid microwave‐assisted solvent extraction method for assessment of stabilizer concentration in crosslinked polydimethylsiloxane

Crosslinked polydimethylsiloxanes were prepared containing 0.05 to 0.2 wt % of either a phenolic antioxidant (Irganox® 1010) or a hindered amine stabilizer (Tinuvin® 144). The stabilizer concentration was assessed by HPLC and UV‐Vis spectroscopy of Soxhlet and microwave‐assisted solvent extracts. Almost complete recovery of stabilizer was achieved with Soxhlet extraction. High stabilizer recovery was achieved when acetone was used as the solvent in the microwave‐assisted extraction. HPLC was shown to be an efficient method for determining the concentration of Irganox 1010. For Tinuvin 144 the selectivity of both UV‐Vis spectroscopy and HPLC was poor, leading to imprecise evaluation of the antioxidant concentration. The loss of stabilizer by migration from polymer to hot water (75 and 95°C) was monitored for the systems stabilized with Irganox 1010 and the diffusion coefficient of the antioxidant in the polymer was determined. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2185–2192, 2004     

煤溶剂萃取新技术研究进展

分析了煤溶剂萃取的研究现状,对比了微波溶剂萃取、超临界流体萃取和超声波萃取3种新技术在萃取过程中的优劣及萃取结果,对如何有效、经济、合理地利用煤的问题给予启示.基于当前煤化工的发展状况,对煤的溶剂萃取研究前景进行了展望.     

Comparison of techniques for the extraction of tobacco seed oil

The yield and fatty acid (FA) composition of the oil obtained from the seeds of a semi‐oriental tobacco (Nicotiana tabacum L.) plant, type Otlja, by various recovery techniques, which are: Soxhlet extraction (SE), maceration (ME), indirect and direct ultrasonic extraction (IUE and DUE, respectively) and cold pressing (CP), were compared. The solvent extractions of ground tobacco seeds (TS) were carried out by n‐hexane, while CP was used to recover the oil from the TS. The highest oil yield (32.9 g/100 g, i.e. 93% of the oil content in the seeds) was achieved by CP. Ultrasonically assisted solvent extractions appear to be inefficient in recovering the oil from the ground TS, as the oil yields were only 45–55% of the oil content, depending on the extraction conditions. Independently of the technique applied, linoleic acid was the major FA of the tobacco seed oil (TSO). The compositions of the TSO extracted by SE, ME, IUE and CP were very similar to each other, and the composition of the TSO recovered by DUE depended on the ultrasonic power input. The content of linoleic acid was reduced, while the content of saturated FA was increased by increasing the ultrasonic power from 5 to 50 W.     

不同地区茶叶黄酮类物质超声波法提取工艺研究

以浙江的茶叶为原料,乙醇为提取溶剂,通过超声波辅助提高提取效率,优化黄酮类物质的提取工艺,并用紫外分光光度法测定含黄酮类物质的量,结果表明较索氏提取好,通过多次正交实验得出在80℃和60%功率下用80%乙醇以1∶60提取25 min为最佳提取条件,并在此条件下对浙江、云南、福建三地茶叶进行含量测定,得出浙江地区茶叶含黄酮类物质最多,其次云南地区,含量最少为福建地区。