不同方法提取白根独活挥发油的对比分析

用水蒸气蒸馏法、乙醚萃取法、超声波萃取法和微波萃取法提取了白根独活中的挥发油,用GC-MS分离鉴定了其成分并测定了各成分相对质量分数。水蒸气蒸馏法、乙醚萃取法、超声波萃取法和微波萃取法挥发油提取率分别为2.29%、3.27%、4.13%和3.78%,分别鉴定出21、24、38和23种化合物,其中共有化合物9种,即蒿苯内酯、α-甜没药醇、辛醛、2-壬酮、十六烷酸甲酯、2-甲基辛烷、(-)-蓝桉烯、3-甲基辛烷、壬烷,相对质量分数最高者为蒿苯内酯。4种不同提取方法所得的白根独活挥发油成分存在差异,但也有共同特征。超声波萃取法和微波萃取法提取挥发油得率更高,成分更全面。     

中华苦荬菜总黄酮和总三萜提取工艺优化研究

以中华苦荬菜的总黄酮和总三萜为筛选指标,分别对索氏提取、超声波提取、微波提取设计正交试验,比较3种方法对有效成分的提取效率。每种方法得到优化整合方案,最后进行得率比较,优选最佳提取工艺。结果表明超声波提取法对总黄酮和总三萜提取得率最高,单次提取即可同时达到2种物质提取率的较好方法。其最佳条件为80%乙醇,在45℃条件下提取40 min。该法简便,提取率高,可用于快速提取中华苦荬菜中的有效成分。     

芦荟苷的提取工艺研究

介绍了芦荟的作用、应用价值及其在各个领域的应用情况,并对现有的芦荟提取方法(浸提法、渗流法、索氏提取法、超声波提取法、有机溶剂萃取法、超临界萃取法、微波提取法等)进行了综述。     

响应曲面优化-微波辅助提取金盏花总黄酮工艺研究及功效评价

采取循环超声波提取法、索氏提取法、微波提取法提取金盏花总黄酮,结果得出微波提取法时间短、效率高。利用单因素法和响应曲面分析法研究微波法提取金盏花总黄酮的最佳条件为提取时间为2.1 min,提取固液比为1∶30 (g/mL),提取温度为63℃,金盏花总黄酮提取率为3.48%;并就金盏花总黄酮提取液进行了抗紫外线能力和抗氧化能力测试,制备了金盏花总黄酮提取液保湿乳就其保湿功能进行了评价。     

超声微波协同萃取枸杞黄酮的工艺研究

采用超声微波协同萃取技术对枸杞中的总黄酮进行快速提取。在单因素实验的基础上设计正交实验对提取工艺条件进行优化,得到最佳条件为:提取温度50℃,提取液为60%的乙醇,料液比为1∶20,提取时间20min,在此条件下枸杞中黄酮的提取率可达1.98%。同时还将超声微波协同萃取法与传统冷凝回流法、超声波辅助提取法和微波提取法进行对比。结果表明,超声微波协同萃取法不仅简单高效,同时快速节能,非常适合枸杞中黄酮类化合物的提取。     

海燕皂苷抑制ACE活性的研究

目的：研究海燕皂苷的降血压活性。方法：采用三种不同方法对海燕皂苷进行提取,采用大孔树脂柱色谱进行分离,对其提取物中分离得到的三种皂苷化合物进行了ACE抑制活性的检测。结论：三种样品均具有一定的抑制ACE活性,微波辅助萃取法、超声波辅助萃取法以及索氏提取法所得海燕皂苷样品的EC50值分别为13.4、12.6、12.9 m...     

超声微波协同萃取维药雪菊中总黄酮工艺研究

研究及优化了超声微波协同萃取维药雪菊中总黄酮的工艺。以雪菊中总黄酮含量为指标,通过单因素实验确定影响总黄酮主要因素,再通过正交试验确定影响总黄酮提取的主要因素的最佳水平。结果表明,最佳提取条件为:提取时间为60 min,超声-微波提取功率为100 W,料液比为1∶20(W/V),提取液为50%乙醇,含量为20.33%。该试验筛选出超声微波协同萃取法提取雪菊中总黄酮的最佳条件,该法具有工艺简单、快速、高效、环保等优点。     

柑橘皮总黄酮的提取及抗氧化性研究

采取乙醇索氏提取法、纤维素酶辅助法、微波提取法以及超声波提取法从柑橘皮中提取总黄酮,研究了用超声波法得到的柑橘皮提取物中总黄酮对O2-·和·OH的抗氧化活性。结果表明,超声波法提取柑橘皮中总黄酮提取率最高,可达1.583%。柑橘皮提取物中总黄酮对O2-·和·OH清除能力良好。为柑橘皮作为天然抗氧化剂和功能性食品的开发利用提供了理论基础和实验依据。     

水性涂料VOG的气相色谱-质谱检测前处理方法研究

对水性涂料挥发性有机化合物（VOC）检测的前处理方法进行了研究.分别采用搅拌萃取法和超声波萃取法对水性涂料中28种VOC进行提取,采用离心方法提取清液,采用气相色谱-质谱法测定并计算回收率.通过比较,确定以二氯甲烷为萃取溶剂、搅拌时间为40 min的搅拌萃取法提取效率更高,采用该方法对28种VOC的加标回收率在94％～116％之间.     

用不同方法提取虎杖中白藜芦醇的比较

以虎杖为原料用乙醇浸提法、碱提酸沉法、超声波萃取法、CO₂超临界萃取法4种方法提取白藜芦醇,采用高效液相色谱法检验虎杖中白藜芦醇含量。以白藜芦醇收率为考察标准,进行提取方法的比较。综合比较分析得出超声波萃取法是以上4种方法中最好的。     

电子电器产品中含溴阻燃剂的萃取

电子电器产品中含溴阻燃剂的萃取方法有索氏萃取、自动索氏萃取、超声波萃取、超临器萃取、微波辅助萃取和快速溶剂萃取等.文章通过对比索氏萃取、微波辅助萃取和快速溶剂萃取并结合高效液相色谱法测定电子塑料产品中的含溴阻燃剂,探讨合适的萃取方法,实验结果表明,索氏萃取效果最好,回率91.8%～98.4%,RSD%=5,满足检测要求...     

当归挥发油的提取与成分分析

采用常压水蒸汽蒸馏法、超声波提取法、微波提取法提取当归挥发油,实验表明采用微波提取法在微波功率720 W、萃取时间120 s、100 mL环己烷中的收率最高,为1.04%.并采用GC-MS联用技术对3种方法提取到的挥发油进行了成分和含量分析,主要成分是当归的活性成分藁本内酯.     

Extraction Kinetics and Anethole Content of Fennel (Foeniculum vulgare) and Anise Seed (Pimpinella anisum) Extracts Obtained by Soxhlet,Ultrasound, Percolation,Centrifugation, and Steam Distillation

Foeniculum vulgare (fennel) and Pimpinella anisum (anise) extracts were obtained by Soxhlet, cold percolation, ultrasound assisted extraction, and centrifugal extraction using ethanol as solvent; anise extracts were also obtained by steam distillation. Soxhlet presented the highest yields for both fennel and anise seed (16.8% and 23.3%, respectively). The highest anethole content among ethanolic extracts was obtained for centrifugal extraction (6.8 mg/g and 143 mg/g for fennel and anise extracts, respectively). Steam distillation presented low yield (0.26%), but high anethole content (68–98%, area). Anise ethanolic extracts also tested positive for flavonoids.     

红外光谱法测定虎舌红提取物中的总黄酮

采用索氏回流法及溶剂萃取法成功地提取了虎舌红中的总黄酮,并对其结构进行了鉴定,采用红外光谱法对提取物中总黄酮的含量进行了测定.结果表明,虎舌红提取物中总黄酮含量为19.47 mg·g-1,与紫外可见分光光度法测定结果基本一致;相对标准偏差(RSD)为2.09％(n=6),加标回收率为93.54％～104.35％,平均回...     

Focused Microwave (FMW) Extraction of Polycyclic Aromatic Hydrocarbons (PAHs) from Plant Bioindicators,Comparison with Classical Techniques

Extraction efficiencies of polycyclic aromatic compounds (PAHs) from spruce needles (Picea abies) obtained by recently introduced “focused microwave assisted (FMW) extraction” (i) and conventional methods represented by extraction enhanced by sonication (ii) and Soxhlet extraction (iii) were compared. n-Hexane:acetone (azeotropic ratio, 53.5 wt % of acetone) extraction mixture was used in all experiments. The influence of various parameters (extraction time, intensity of irradiation, moisture content) both on the recoveries of PAHs from spruce needles (Picea abies) and the amount of co-isolated matrix components potentially interfering within the determinative step was examined. The mean extraction efficiencies of PAHs obtained by FMW extraction and sonication were found to be lower (82 % and 75 %, respectively) compared the extraction in Soxhlet apparatus (equal 100 %).     

Effect of Different Extraction Processes on the Recovery of Extracts from Achyrocline satureioides D.C.: An Evaluation of Antioxidant Activity

Abstract

In the present work, the global yield, composition, and antioxidant activities of the extracts from Achyrocline satureioides obtained by different separation techniques were evaluated. Centrifugation, hydrodistillation, low pressure solvent extraction (LPSE), Soxhlet, supercritical fluid extraction, and ultrasound processes were used. The total phenolic compounds and quercetin present in the extracts were quantified. The antioxidant activity of the extracts was evaluated by the coupled reaction of β‐carotene/linolenic acid. Higher global yields were obtained by LPSE and Soxhlet. The analysis indicated the presence of flavonoids in all extracts. The antioxidant activities of the extracts were larger than that of the reference substance, β‐carotene.     

Supercritical Fluid Extraction Of Lemon Verbena (Aloysia triphylla): Process Kinetics and Scale-Up,Extract Chemical Composition and Antioxidant Activity,and Economic Evaluation

The extract of lemon verbena ( Aloysia triphylla ) was obtained by supercritical fluid extraction (SFE) using laboratory and pilot scale equipments. The scale-up criterion selected (maintaining solvent to feed ratio constant) was successfully used for a 14-fold scale-up. The extract obtained in pilot scale was separated in three fractions, which were characterized as for their phytochemical profile, total flavonoids content, and antioxidant activity. The extracts obtained by SFE were compared to classical Soxhlet extraction method. Maximum yield obtained for SFE was 1.8%, and for Soxhlet, 7.1%. The chemical composition revealed different phytochemical profiles for SFE and Soxhlet extracts; the last ones presented more flavonoids, while SFE extracts were more concentrated in volatile compounds. The major compounds identified in the volatile fraction of the extracts were spathulenol, phytol and octadecatrienal. Some extracts presented pro-oxidant activity and others presented antioxidant activity. The SFE process was shown to be economically feasible for obtaining lemon verbena extracts; the minimum manufacturing cost (COM) obtained was US$ 1070.00/kg, with a payback time of 2 years.     

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。     

龙眼果皮不同方法提取物对自由基的清除作用

用超声波、微波、冷凝回流及常温浸泡4种方法,用φ(C2H5OH)=95%的乙醇提取龙眼果皮,分别得到超声波提取物(UE)、微波提取物(ME)、热提物(RE)和浸提物(DE)。然后采用二苯代苦味酰肼自由基(DPPH)法对不同质量浓度的各提取物进行了自由基清除实验。结果表明,龙眼果皮乙醇提取物对自由基有很强的清除作用,清除能力远远优于3,5-二叔丁基-4-羟基甲苯(BHT);不同的提取方法所得提取物对自由基的清除作用有显著差别,其中以ME的效果最佳,当其质量浓度为1.2 mg/mL时,最大清除率高达83.11%。     

Enhanced extraction efficiency of bioactive compounds and antioxidant activity from Hippophae rhamnoides L. by-products using a fast and efficient extraction method

In this study, a novel method named high-speed homogenization coupled with ultrasound-assisted extraction (HSH-UAE) followed by high-performance liquid chromatography (HPLC) was employed and investigated for the extraction and determination of main flavonoids rutin, quercetin-3-O-glucoside, quercetin, kaempferol and isorhamnetin from Hippophae rhamnoides L. by-products. Optimal conditions for HSH-UAE, proposed by the single factor and the Box–Behnken design (BBD) tests coupled with response surface methodology (RSM), were 68% ethanol concentration, ultrasonic power 250 W, homogenate speed 9000 rpm, liquid/solid ratio 22 mL/g and extraction time 12 min. The extraction yields of five main flavonoids were significantly improved by HSH-UAE than UAE and high-speed homogenization-assisted extraction (HSHAE). Furthermore, the antioxidant activity of HSH-UAE extracts was assessed by 1,1-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assays with IC₅₀ value of 0.091 mg/mL and 2.837 mmol FeSO₄/g DW. Good linear ranges were obtained for five main flavonoids in the range of 2.5–500 μg/mL with the coefficient higher than 0.99. The recoveries of the five flavonoids were in the range of 97.87–99.26%. The limit of detection (LOD) and the limit of quantification (LOQ) for the main flavonoids were within the ranges of 0.28–0.46 and 0.89–1.74 μg/mL, respectively. The present results showed that the proposed method HSH-UAE could be developed as a fast and efficient method for extracting the active ingredients from medical edible plant materials for potential application.