微波-表面活性剂协同提取山竹外衣色素

研究了微波-表面活性剂协同提取法(MAME)提取山竹外衣色素的工艺条件与过程。考察了提取剂中表面活性剂类型和含量、提取液pH、微波提取功率、时间、浸泡固液质量比和时间对色素提取率的影响,实验结果表明:pH=1时,以w(聚氧乙烯十二酸失水山梨醇单酯)=0.08%的乙醇溶液〔φ(CH3CH2OH)=70%〕为提取剂,山竹外衣按m(山竹外衣)∶m(提取剂)=1∶263浸泡于提取剂中5 m in、微波功率800 W下提取25 s,色素提取率为96.26%。该法一次提取率是传统溶剂法的1.78倍,提取时间是溶剂法的1/240,聚氧乙烯十二酸失水山梨醇单酯对色素提取有增溶作用。     

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 %).     

Cloud Point Extraction and Pre-Concentration of Four Alkaloids in Nelumbo nucifera Leaves by Ultrahigh Pressure-Assisted Extraction

A rapid micellar extraction and pre-concentration method by ultrahigh pressure-assisted was developed for four alkaloids in Nelumbo nucifera leaves. Nonionic surfactant polyoxyethylene octylphenol ether (OP-10) solution was selected as solvent. Various experimental conditions were investigated to optimize the extraction and pre-concentration process. The optimal UPE condition was 5% OP-10 (w/w) solution, 400 MPa of pressure, 1 min of extraction time, and 1:20 (g/mL) of solid/liquid ratio. The pre-concentration of alkaloids was achieved by cloud-point extraction (CPE) and the optimum CPE condition was incubated in a thermostatic water bath at 55°C for 10 min, with 10% OP-10 and 15% sodium chloride added into the solution. The pre-concentration factor (CF) value was 11.6 ± 0.127, and the CPE recoveries for O-nornuciferine, N-nornuciferine, nuciferine, and roemerine were 91.0%, 92.3%, 92.7%, and 94.5%, respectively.     

季铵盐在胶束催化肉桂醛水解中的作用

测定了十六烷基三甲基溴化铵(CTAB)胶束体系中不同温度及碱浓度下的肉桂醛水解反应速率,比较了四丁基溴化铵(TBAB)对CTAB、十二烷基硫酸钠(SDS)、聚氧乙烯月桂醚(Brij-35)胶束体系中肉桂醛水解转化率的影响。实验结果表明,当0.003 mol/Lc(CTAB)0.02 mol/L时,肉桂醛水解反应中碱的浓度可从0.1 mol/L下降至0.02 mol/L、反应温度可从318 K下降至298 K,而胶束体系中的反应速率常数基本等于非胶束体系;肉桂醛的转化率(η)依次为η(CTAB+TBAB)η(Brij-35+TBAB)η(CTAB)η(Brij-35)η〔non-(surfactant+TBAB)〕η(SDS+TBAB)η(SDS),且随着TBAB浓度的增加,各胶束体系中肉桂醛的转化率均增大,表明TBAB与胶束催化之间存在着协同作用,它能提高胶束催化的效率。     

Problems in the Extraction of Polycyclic Aromatic Hydrocarbons from Diesel Particulate Matter

In this work, a comparison between Soxhlet, ultrasonic, and microwave-assisted extraction (MAE) (using hexane:acetone 1:1) of polycyclic aromatic hydrocarbons (PAHs) from SRM 1650 diesel particulate matter was made. As good recoveries were not obtained for the higher molecular weight compounds, MAE with toluene and dichloromethane was also tested. Achieved recoveries were compared with the results obtained in the same assays made with SRM 1648 urban particulate matter and real atmospheric particulate samples. In order to explain the difficulty of the extraction of PAHs from SRM 1650 in comparison to SRM 1648 and real atmospheric particulate samples, elemental analysis, X-ray diffraction, and particle analysis using scanning electron microscopy coupled to an automatic computer imaging system were also made. It is important to notice that SRM 1650 shows a high percentage of carbon and differences in the morphology of the particles between SRM 1650 and SRM 1648 were observed.     

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。     

Solid Phase Extraction for Determination of Polycyclic Aromatic Hydrocarbons from Atmospheric Wet and Dry Deposition Samples

Solid phase extraction with C-18 sorbent tubes was employed for extraction and preconcentration of trace level (ng/l) of polycyclic aromatic hydrocarbons (PAHs) from water samples obtained by collecting wet and dry atmospheric deposition. Recoveries of spiked PAHs from 0.2 to 10.0 l water samples ranged from 60% to 90%. Five deuterated PAHs (naphthalene- d 8 , acenaphthene- d 10 , anthracene- d 10 , chrysene- d 12 , and perylene- d 12 ) were added to the samples as surrogates. The recoveries of surrogates were in the same range as the spiked PAHs. The recoveries of surrogates were used to estimate the recoveries of ambient PAHs with a similar ring structure. Factors that contributed to the relatively low recoveries include breakthrough of the sorbates, adsorption on the container surface, and degradation in water during storage.     

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...     

An evaluation of supercritical fluid extraction as an analytical tool to determine fat in canola,flax, solin,and mustard

Supercritical fluid extraction (SFE) with carbon dioxide was used to extract oil from soft oilseeds (flax, solin, canola, and mustard). Oil content determinations from the SFE method AOCS Am 3–96, with and without ethanol as a modifier, were compared to results obtained with an exhaustive extraction using petroleum ether (FOSFA as in AOCS Am 2–93). Without the modifier, oil recoveries using SFE were 10 to 15% lower than oil contents by the FOSFA method for the flax and canola samples. For mustard, the oil recoveries by SFE were about 20 to 30% lower than oil contents by the FOSFA method. In the presence of the modifier, oil recoveries for flax and canola were about 3% lower than the FOSFA recoveries. Varying the time, temperature, and amount of modifier (ethanol) showed that recoveries increased with time, pressure, temperature, and amount of modifier independently of the oilseeds tested. Kinetics of the SFE extraction showed that the oil recoveries increased with the extraction time and reached a plateau after 60 min. Multiple extractions (2×30 min), however, gave better recoveries than a single extraction for the same amount of time (60 min). The best results were obtained using multiple extractions without modifier or a combination of multiple extractions first without and then with 15% modifier. Under these last two conditions, oil recoveries were close to 100% for flax, solin, and canola, but mustard oil recoveries were still 10% lower than recoveries using the FOSFA method. Mustard samples gave the lowest oil recovery from SFE when compared to FOSFA method recoveries whatever conditions were tested, suggesting a matrix effect on the oil recovery. The acyl lipid content of the various extracts was studied using the sum of all FA expressed as TAG as a measure of acyl lipid extraction. The acyl lipid contents of the extracts were close to 100% when no modifier was used during the SFE. In the presence of modifier, the acyl lipid contents of the extracts were 10 to 15% lower than the results obtained without modifier. The amount of acyl lipid in the extract decreased as the quantity of modifier increased. This suggests that increasing the ethanol modifier increased the amount of polar compounds extracted without significantly increasing the total amount of lipids. The FA profiles were constant throughout the various extraction procedures.     

非离子表面活性剂C12E10的浊点分相行为及其应用

引言 络合萃取技术对极性有机物稀溶液和金属离子的分离具有高效性和高选择性,已广泛应用于湿法冶金领域.由于萃取剂在萃残液中分子水平的溶解以及萃取塔器操作时水相对于萃取剂相细小液滴的夹带,造成了一定程度的萃取剂流失和环境污染,同时,由于萃取剂大都分子量较大,生物降解性能不佳[1],因此,开展从水溶液中回收萃取剂的研究是十分必要的.     

中药植物战骨总黄酮的提取

用传统索氏提取法及现代提取方法——微波萃取法、超声波萃取法、内部汽化法4种不同的提取方法对战骨中的总黄酮进行了提取工艺研究。采用上述4种方法对战骨中总黄酮进行提取,并进行了后3种方法的L9(34)正交设计性实验。测定了以上4种方法的战骨提取液的总黄酮含量及回收率,并将后3种方法与索氏提取法进行比较。结果表明,微波萃取法、超声波萃取法、内部汽化法的最优方案的收率分别为2.07%,1.90%,1.78%,平均回收率分别为100.60%,105.12%,99.92%,相对标准偏差分别为1.40%,1.47%,1.16%。索氏提取法提取的收率为0.95%。现代方法的收率均高于传统索氏提取法。     

Separation and Purification of Three High-Purity Isoflavonoids from Belamcanda chinensis (L.) DC. by Supercritical Fluid Extraction and High-Speed Counter-Current Chromatography

Supercritical fluid extraction (SFE) was used to extract three isoflavonoids including irigenin, irisfloretin and dichtomitin from Belamcanda chinensis (L.) DC. The parameters including pressure, temperature, sample particle size, and flow rate of CO₂ were optimized with an orthogonal test. Under the optimized conditions of 15 MPa, 55°C, a sample particle size of 20–40 mesh and CO₂ flow rate of 40 L h^?1. The process was then scaled up by 10 times using a preparative SFE system. The yield of the crude extract from SFE was 4.1%, which contained irigenin, irisfloretin, and dichtomitin 0.71%, 0.49%, and 0.05%, respectively. To compare the extraction methods, Soxhlet Extraction (SE) was performed. The results indicated that SFE was better than SE. Irigenin, irisfloretin, and dichtomitin in the SFE extract were then separated and purified by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of petroleum ether–ethyl acetate–methanol–water (2:4:3:3, v/v). From 5.0 g of dry crude extract, 27.8 mg irigenin, 16.4 mg irisfloretin, and 2.1 mg dichtomitin were obtained at purities of 97.1%, 96.4%, and 98.0%, respectively, as determined by HPLC-PDA. These results well indicate that SFE and HSCCC are very powerful techniques for the extraction and purification of irigenin, irisfloretin, and dichtomitin from B. chinensis.     

一种浓缩洗衣液配方的初步研究

使用L_9(3~4)正交试验,初步研究了脂肪醇聚氧乙烯醚硫酸钠(AES)、十二烷基苯磺酸(LAS)、脂肪酸甲酯乙氧基化物(FMEE)及脂肪醇聚氧乙烯醚(AEO_7)等4种常用表面活性剂在浓缩洗衣液体系中的应用。通过对去污力和水溶性等性质的测试,优化出一种浓缩洗衣液的基础配方为12%AES、12%LAS、10%FMEE、10%AEO_7、3%乙醇,其他0.7%,去离子水补足。该配方不会出现凝胶现象且去污测试结果分别为1.22(JB01)、2.94(JB02)、1.45(JB03),溶解性评分为3分。     

乐昌含笑叶挥发油超声波提取工艺优化及化学成分分析

乐昌含笑具有抗氧化活性,为阐明其作用机理,该文对乐昌含笑叶挥发油进行了提取工艺及化学成分研究。采用超声波法提取挥发油,用正交设计实验优化了各提取参数。萃取的优化条件为V(正戊烷)∶V(乙醚)=1∶2为萃取剂、m(萃取剂)/m(样品)=10、超声时间30 m in。在优化条件下,其挥发油的收率为2.48%。用毛细管气相色谱-质谱联用法结合计算机检索对挥发油化学成分进行了分析和鉴定,从乐昌含笑叶挥发油中共鉴定出42种成分。用气相色谱峰面积归一法测定了各化合物的相对质量分数,占总峰面积的88.66%。乐昌含笑叶挥发油主要成分为大根香叶烯A(10.53%)、(E,E)-金合欢醇(7.53%)、β-丁香烯(6.44%)、α-没药醇(6.16%)、β-榄香醇(6.14%)、莪术烯(4.28%)、长叶烯酮(3.50%)、α-荜澄茄烯(3.25%)和γ-杜松烯(3.23%)。     

Determination of heavy hydrocarbon contamination using supercritical fluid extraction with infrared detection

Supercritical fluid extraction (s.f.e.) conditions to extract heavy hydrocarbons quantitatively from soil were developed, using high temperature (150 °C) and an infrared-clear organic solvent. S.f.e. with pure CO₂ at 65 °C gave good recovery of light crude oil components ( C25 alkanes) but did not efficiently extract heavier components. An increase in temperature during s.f.e. to 150 °C increased the recovery of the heavier hydrocarbons, but the best recoveries were achieved by extraction at 150 °C after addition of perchloroethylene as a modifier. Under these conditions s.f.e. (15 min static followed by 15 min dynamic extraction) gave recoveries 5–45% higher than did 4 h of Soxhlet extraction for soils contaminated with light to heavy crude oils, motor oil and heavy residual oil. Adsorption of the extracted polar compounds on silica indicated that both polar and non-polar organics were more efficiently extracted by s.f.e., Since the modifier is added directly to the soil sample, the method does not require either dual pumps or premixed fluids.     

丙烯酸酯微乳液动力学研究

采用一次投料法,以烯丙氧基壬基酚聚氧乙烯(10)醚硫酸铵(DNS-86)和辛基酚聚氧乙烯(10)醚(OP-10)为乳化剂制备了固含量为10%的纯丙微乳液,对其聚合反应动力学进行了研究。结果表明:温度对纯丙微乳液聚合反应的最终转化率没有影响;整个反应过程不存在恒速期;但随温度的升高乳胶粒粒径减小,反应速率增快,乳液的聚合稳定性下降;纯丙微乳液聚合成核方式主要以胶束成核为主。     

氧乐果可溶性液剂的研究

在氧乐果可溶性液剂的制备中,我们对溶剂、助溶剂、乳化剂、稳定剂进行了研究。筛选出了两个最佳配方：氧乐果50％(质量浓度),苯乙基酚聚氧乙烯聚氧丙烯醚2．5％,烷基酚甲醛树脂聚氧乙烯醚0．7％,无水十二烷基苯磺酸钙(500^#)1.8％,稳定剂0．2％,助溶剂5％,溶剂补加到100％;氧乐果80％(质量浓度),苯乙基酚聚氧乙烯聚氧丙烯醚3％,烷基酚甲醛树脂聚氧乙烯醚0．9％,无水十二烷基苯磺酸钙(500^#)2．2％,稳定剂0．5％,助溶剂6％,溶剂补加到100％。用两种配方生产的产品性能优良。田间试验结果表明,防效优于乳油。     

A simplified gas liquid chromatographic determination for vitamin E in vegetable oils

A simple and rapid procedure has been developed for the isolation, concentration, esterification, and gas liquid Chromatographic (GLC) quantitation for the Vitamin E content of vegetable oils. Vitamin E is determined by saponification of the oil, ether extraction of the saponified mixture, drying and evaporation of the extract, followed by closed tube esterification and quantitation of the butyrate ester using a gas Chromatograph equipped with a hydrogen flame ionization detector. This technique eliminates the conventional thin layer Chromatographie isolation of Vitamin E normally used prior to direct or trimethylsilyl (TMS) derivative GLC quantitations. Oils fortified with Vitamin E in the 5 to 40 milligrams per 100 grams range showed recoveries of 93.4 to 98.6%.     

Supercritical fluid extraction of wood pulp with analysis by capillary gas chromatography-mass spectrometry

A supercritical fluid (SF) extraction method for the analysis of extractable material in eight hardwood and softwood pulp samples was investigated. While the majority of the extractable material in a Soxhlet extract with methylene chloride was determined to be fatty acids, the presence of their corresponding methyl esters along with fatty acids was noted in the SF extract. Grinding the samples increased extractable fatty acid methyl esters (FAMEs) by 10-fold, and in-situ derivatizations resulted in higher FAME recoveries than derivatization after SFE. Liquid trapping enhanced recoveries of lower FAMEs when compared with tandem (solid/liquid) trapping. In-situ acetylations sometimes yielded acetylated glucoses during SFE. Large differences in FAME concentrations were seen for hardwood samples, but lesser differences were seen for the softwood pulp samples.     

The determination of polyoxyethylene nonionic surfactants in water at the parts per million level

A method has been developed to determine the concn of polyoxyethylene nonionic surfactant (PNS) in the parts/million concn range in a water-bacteria medium. The method has successfully determined the concn of PNS during the course of biodegradation studies using either activated sludge or river water as the bacterial source. The nonionic surfactant was removed from the water solution by continuous ether extraction. Detection and measurement of the PNS was accomplished using cobalt thiocyanate and measuring the absorbance of the blue cobalt-PNS complex at 620 m.03 in a five-cm absorption cell. Optimum extraction conditions required a neutral pH and a low ionic strength. The colorimetric step required that each molecule of PNS contain at least six ethylene oxide units for color development, and since the absorbance varies with the length of the polyoxyethylene chain, the method must be standardized using the particular compound under investigation.