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1.
自制超临界流体萃取仪操作条件的优化及其应用   总被引:5,自引:8,他引:5  
林伟生  王国俊 《分析化学》1995,23(7):765-769
超临界流体萃取是近年来发展起来的一种新的分离技术。本文使用自己研制的超临界流体萃取仪对吸附有痕量正构烷烃的Al2O3进行萃取,对各种操作条件进行优化。并对卢柑皮及生姜样品进行初步的萃取分析。结果证明该仪器设计合理,具有操作简便、高效、自动化程度高的优点,为复杂样品中痕量组分的萃取分析奠定了基础。  相似文献   

2.
超临界流体萃取仪器的研制   总被引:1,自引:1,他引:1  
崔兆杰  张新保 《分析化学》1995,23(12):1462-1466
本文报道了以国产原配件为基础,成功地研制了分析规模的超临界流体萃取仪器、并对仪器性能进行了全面考察,仪器性能稳定,重现性良好(RSD<3.1%),定量线性关系可靠,可满足定量萃取的要求。  相似文献   

3.
黄金冶炼厂中萃取法提铜   总被引:1,自引:0,他引:1  
周学玺  朱屯 《应用化学》1994,11(4):35-39
研究了羟肟类萃取剂对铜及主要杂质铁的萃取行为,并进行了串级流动试验,考察了铜、铁的分离效果,确定了不影响黄金收率的最佳铜、铁萃取分离流程。  相似文献   

4.
酰胺荚醚对镧系和锕系元素萃取性能的研究   总被引:2,自引:0,他引:2  
以酰胺莱醚为萃取剂,正辛醇和煤油的混合的作然释剂,研究了水相硝酸浓度和不同结构酰胺莱醚对镧系和锕系元素萃取分配比的影响,并对它们的萃取性能进行了比较,结果表明,适当的酰胺莱醚可以有效地从硝酸溶液中萃取镧系和锕系元素。  相似文献   

5.
十二烷基苯磺酰胺喹啉作载体的液膜法提取水中铅的研究   总被引:6,自引:0,他引:6  
研究了十二烷基苯磺酰胺喹啉萃取铅(Ⅱ)的行为。研究表明,此种萃取剂在一定的条件下,能有效萃取铅(Ⅱ),并采用斜率法探讨了对铅(Ⅱ)的萃取机理。在此基础上,研究了该萃取剂作为载体的乳状液膜对铅的提取。  相似文献   

6.
固相微萃取技术在农药残留分析中的应用   总被引:1,自引:0,他引:1  
固相微萃取技术是一种崭新的无溶剂萃取分离技术。文中对影响萃取效果的因素进行了综述,并对固相微萃取技术在农药残留分析中的应用作出概述,引用文献56篇。  相似文献   

7.
云南褐煤CO/H2O超临界萃取产物结构分析   总被引:1,自引:0,他引:1  
对云南先锋褐煤CO/H2O超临界萃取产物进行了元素分析、平均分子量测定和H-NMR、FTIR分析。结果表明,萃取物具有较小的结构单元和较高的杂原子含量,主要由芳环数为2-5,并具有烷基和酚羟基取代度28-46%的取代芳香结构组成。对正已烷可溶物柱色谱烷烃馏分和芳烃馏分进行了GC/MS分析,在烷烃馏分中检测出一系列烯烃存在,表明在萃取过程中有裂解反就 发生;芳烃馏分以基萘和烷基四氢萘为主要成分,取代  相似文献   

8.
本文首次报道了标题试剂H2A对钯的萃取行为,确定了萃取物的组成,讨论了萃取机理,算出了萃取平衡常数.通过化学分析、红外及拉曼光谱、紫外光谱,研究得出了萃合物的结构,并且实现了H2A从钯-铂混合溶液中选择性萃取钯.  相似文献   

9.
研究了盐析剂浓度和水相PH值对分配比D的影响。研究了烷基膦酸萃取剂P507和喹吉林 类萃取剂N601协萃锗的机理,并对萃取平衡常数和热效应进行了估算。  相似文献   

10.
基于单级手性萃取数学模型和质量守恒定律,建立了多级离心手性萃取数学模型,设计了多级离心萃取数学模型程序,并对多级离心萃取分离苯基琥珀酸(PSA)对映体进行了模拟.模拟了相比、萃取剂浓度、对映体浓度、进料位置和萃取级数等工艺参数对萃取效果(产物纯度和产率)的影响.模拟结果表明,考察的工艺参数共同影响萃取相和萃余相的产物纯度及产率;采用中间位置进料和较大的W/F相比有利于对称分离.实验发现:采用中间位置进料,10级离心萃取后萃取相中苯基琥珀酸的光学纯度ee(对映体过量)达到56%以上.模拟结果还表明,采用26级离心萃取器,中间进料,逆流分级萃取,萃取相及萃余相中的光学纯度ee都能达到98%以上.  相似文献   

11.
The extraction of geniposidic acid and geniposide from Eucommia ulmoides was carried out by Soxhlet extraction, enzyme-assisted aqueous extraction, semi-bionic extraction and supercritical fluid extraction techniques and the extracts were analyzed by high performance liquid chromatography. The results showed that the best methods for extraction of geniposidic acid and geniposide are enzyme-assisted aqueous extraction and semi-bionic extraction. Compared with various extraction methods, the semi-bionic extraction was more efficient, yielding the highest amount of geniposidic acid and geniposide. In semi-bionic extraction, no organic solvent was used. Semi-bionic extraction was performed at the same pH as that of the human body. The results indicated that semi-bionic extraction was the best method for large-scale efficient extraction of geniposidic acid and geniposide from plant materials. The supercritical fluid extraction process required more time than the other methods, and gave the lowest yields of geniposidic acid and geniposide.  相似文献   

12.
A new kind of microwave-assisted circumrotation reflux extraction device was constructed and used to study the extraction technology of gallic acid from phyllanthus urmaria L.The extraction principle of the device was same as that of microwave-assisted solvent extraction but using circumrotation techniques as auxiliary stirrer to accelerate the process.Capillary electrophoresis was used to determinate gallic acid in phyllanthus urmaria L extracts in order to evaluate the extraction efficiency of the method.It was found that the most important factors influencing extraction gallic acid were solvent kind and microwave power.The optimum extraction conditions were as follows:water using as irradiate time 4 minute.Under the optimum extraction conditions,five experiments were carried out and the average extraction rate of gallic acid in phyllanthus urmaria L was 4.32 mg/g,relative standard deviations (R.S.D.) was 2.2%.Compared with other extraction methods e.g.reflux extraction and microwave-assisted extraction,better extraction efficiency was observed for the microwave-assisted circumrotation reflux extraction.  相似文献   

13.
Phyllanthus emblica L. is an economic plant used in Chinese medicine for the treatment of various diseases. The bark of P. emblica is rich in polyphenols and its extractions have shown strong antioxidative and radical scavenging activity. Response surface methodology (RSM) was used to assess the optimal extraction of polyphenols from P. emblica bark. Various extraction parameters including ethanol concentration, extraction time, temperature, solid–liquid ratio, and extraction times were chosen to identify their effects on polyphenols extraction. Among these parameters, extraction times and solvent concentration were found to have significant effect on polyphenols extraction. RSM was applied to obtain the optimal combination of solvent concentration, extraction time, temperature, and extraction time for maximum rate of extraction. The most suitable condition for the extraction of polyphenols was at ethanol concentration 75%, extraction time 25 min, extraction temperature 45°C, and extraction times 3. At these optimal extraction parameters, the maximum extraction of polyphenols obtained experimentally was found to be very close to its predicted value. The extraction rate of polyphenols was 19.78% at the optimum conditions. The mathematical model developed was found to fit with the experimental data of polyphenols extraction.  相似文献   

14.
正交实验法在小麦粉中甲醛振荡提取条件的应用研究   总被引:1,自引:0,他引:1  
小麦粉中甲醛的提取问题是一个比较复杂的多因素问题。采用正交实验法,选用L9(34)正交实验表,在提取试剂、提取温度、提取时间等多个因素和水平中优选小麦粉中甲醛振荡提取的最佳条件。实验中甲醛提取量采用Nash试剂柱前衍生高效液相色谱法测定。结果表明,提取温度是小麦粉中甲醛提取的最主要因素,最佳的提取条件为提取温度30℃、提取液为硫酸钠、提取时间为40min。  相似文献   

15.
建立了超声微波酶解协同提取油茶壳中原花青素的方法。通过单因素试验,探讨了超声微波协同提取油茶壳中原花青素过程中各主要因素对原花青素提取率的影响规律。实验中发现,往提取液中加入适量纤维素酶,可显著提高原花青素的提取率。在此基础上,通过正交试验,优化并获得了超声微波酶解协同提取原花青素的最适宜条件。最适宜提取条件为:超声波频率40 KHz、微波功率200 W、提取时间60 s、料液比1∶6、提取温度50℃、0.1%纤维素酶0.5 mL、提取次数2次。在最适宜条件下,原花青素的提取率为4.46%,分别是超声提取、微波提取和超声-微波协同提取的4.0、3.3和1.8倍。本文所建立的超声微波酶解协同提取油茶壳中原花青素的方法具有简便、快速、高效和节能等优势,有利于应用推广。  相似文献   

16.
Extraction methods using stirring extraction, Soxhlet extraction, ultrasonic extraction and microwave-assisted extraction (MAE) were evaluated for the percentage extraction of camptothecin (CPT) and 9-methoxycamptothecin (9-Me-CPT) from Nothapodytes foetida. The extracts were analyzed by high performance liquid chromatography (HPLC). Methanol (90%, v/v) extracted high percentage extraction of CPT and 9-Me-CPT compared to ethanol (90%, v/v). The results shows that the percentage extraction of CPT and 9-Me-CPT from N. foetida by MAE was more efficient in short time followed by Soxhlet extraction, ultrasonic and stirring extraction methods. Maximum percentage extraction of CPT (2.67%, w/w) was obtained by MAE technique. MAE has need of 3 min, whereas ultrasonic extraction, Soxhlet extraction and stirring extraction techniques require 30, 120 and 30 min, respectively to leach higher percentage extraction of CPT and 9-Me-CPT. The times taken by the microwave extraction process was 40 times less than the Soxhlet extraction for percentage extraction of alkaloids. The present results show that the extraction efficiency and considerable saving of time by MAE was more competent than the other extraction techniques.  相似文献   

17.
密闭微波辅助萃取当归粉中的阿魏酸   总被引:1,自引:0,他引:1  
利用密闭微波样品制备系统(具有压力控制部件),对当归中的有效成分阿魏酸的萃取进行研究,比较了密闭微波萃取同超声波萃取和索氏萃取阿魏酸提取率的差异.结果表明:微波萃取与其他两种萃取方法相比,具有速度快和萃取率高的特点.并得到了阿魏酸提取的最佳条件:微波功率为400 W,萃取剂为90%的乙醇(体积分数),固-液比为1∶15,微波辐射为240 s,当归粒径为75μm.  相似文献   

18.
采用超声提取法对含羞草种子中黄酮类物质进行提取,对提取工艺条件如溶剂、配料比、浸泡时间、提取温度、提取时间进行了优化。在单试验的基础上进行正交试验,得出黄酮类物质的最佳提取工艺条件:乙醇体积分数为60%,含羞草种子与60%乙醇配料比(g∶m L)为1∶8,超声温度范围40~44℃,超声时间为50 min。该方法操作简单,提取时间短,提取效率较高。  相似文献   

19.
通过对木蹄多糖提取得率有影响的子实体粉末颗粒大小、料水比、提取温度和提取时间进行的单因素研究,其中对料水比、提取温度和提取时间3个因素采用应用响应面法进行了优化,确定了木蹄子实体多糖的最佳提取工艺条件:子实体粉末颗粒60目,料水比1:42.92,提取温度88.92℃,提取时间3.92h,多糖得率达到5.68%。  相似文献   

20.
A comparison of four extraction techniques used for the isolation of 14 explosive compounds (Method 8330-Explosives) from spiked soil samples is described. Soxhlet warm extraction (SWE), pressurized solvent extraction (PSE), microwave assisted extraction (MAE) and supercritical fluid extraction (SFE) were included. The effects of basic extraction conditions – i.e. type of extraction solvent, temperature, pressure, and extraction time – were investigated. The best extraction recovery of the monitored compounds from spiked soil was obtained using pressurized solvent extraction. Recoveries of explosives using the PSE technique were in the range from 65 to 112%. Extraction recoveries by Soxhlet warm extraction and supercritical fluid extraction reached 65–99% and 52–75%, respectively. The lowest extraction recoveries (28–65%) were obtained using microwave assisted extraction. A very low extraction recovery for tetryl was observed in all cases but the best results were achieved by pressurized solvent extraction (58%).  相似文献   

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