微波场协同提取野菊花黄色素的研究

研究了微波提取野菊花 (Chrysanthemumindicum)黄色素的新工艺并确定了最佳工艺条件 :原料为 2 0 0 0 0g野菊干花 ,提取剂为无水乙醇 ,提取剂比例为 1 /70 ,微波功率为 80 0W ,提取时间为 45 0s,提取次数为 3次 ,最佳工艺条件下色素的提取率为 91 1 % ,产率为 1 4 6% ,色价E ( 1 % ,3 2 1nm)为 42 2 ,产品pH值为 6 5。与溶剂浸提法相比 ,微波提取野菊花黄色素的每次提取时间由 1 2h减小为 45 0s,提取率从 88 6%增加到 91 1 %。     

核桃外果皮中棕褐色色素的提取及性质测试

以水为萃取剂,提取晾干的核桃外果皮中棕褐色色素并对其稳定性进行了测试,结果表明,该色素水溶性好,耐热性,耐光性较好。盐、柠檬酸,金属离子对色素的色泽无不良影响,乙醇有增色效应,但易被H2O2氧化逐渐脱色,提取该色素工艺简单,无污染。     

密闭微波辅助萃取天麻中天麻素的研究

应用密闭微波萃取装置,对中药天麻中有效成分天麻素的萃取进行了研究。分别讨论了药材颗粒粒径、提取溶剂浓度、微波提取时间和提取剂的用量对微波萃取天麻素的影响。结果表明:当药材粒径<50μm,乙醇体积分数为50%,微波辐射时间为2min,提取剂质量为药材质量的30倍时,天麻素提取率最高。此外,将微波萃取与索氏萃取和超声波萃取进行了比较。     

微波场协同提取紫背天葵色素的研究

研究了微波提取紫背天葵(Begonia fimbristipula Hance)色素的新工艺,并确定了最佳工艺条件：提取剂为φ(C2H5OH)=60％的乙醇,提取剂与原料用量比为1：60,微波功率为648W,提取时间为200s,提取次数为2次。最佳工艺条件下的色素提取率为96．8％,产率为9．98％,色价E(1％,526m)为10．5,产品pH值为6．5。与溶剂浸提法相比,微波法提取紫背天葵色素的每次提取时间由24h减少到200s,提取率从95．9％增加到96．8％。     

微波辅助萃取新鲜芦荟叶中芦荟甙的研究

应用密闭微波萃取装置对芦荟中的有效成分芦荟甙进行了微波萃取研究,并利用透射电子显微镜对微波萃取机理进行了初步探讨.讨论了不同萃取剂、溶剂浓度、萃取时间和微波功率等对提取率的影响.在萃取剂为乙醇-水体系,溶剂(乙醇)体积分数为70%、萃取时间为4min及微波功率为340W的条件下,萃取效果最佳.与索氏提取及超声波萃取法相比,本法具有萃取速度快、提取率高及溶剂用量少等特点.     

表面活性剂协同微波提取紫背天葵色素的研究

从紫背天葵(begonia fimbristipula hance)中提取了紫背天葵色素,并优化了提取条件;提取剂为0．03％(w)的K12-45％(φ)乙醇水溶液,用量为每克原料加入30mL提取剂,微波功率为464w,提取时间为200s,提取次数为2次提取率为94．8％,产率为9．31％;色价E(1％,510nm)为23．7．产品pH值为6．4与溶剂浸提法相比,每次提取时间减小36倍,提取率增加22．3％。     

微波场协同提取金银花黄色素的研究

研究了应用微波技术从金银花(Lonicera japonicaThunb)中提取黄色素的新工艺,并确定了最佳工艺条件:提取剂为无水乙醇,原料用量(g)与提取剂用量(mL)比为1∶60,提取时间为50 s,微波功率为560 W,提取次数为3次。最佳工艺条件下的色素提取率为83.40%,产品pH值为6。与溶剂浸提法相比,微波法提取金银花黄色素的每次提取时间由1 h减少到50 s,提取率从52.21%增加到83.40%,效果明显优于常规的溶剂浸提法。     

红龙果食用红色素的提取及理化性质分析(Ⅰ)

从红龙果中提取了食用红色素H和副产物,研究了该食用红色素的理化性质,包括红色素的溶解性和可见吸收光谱特征,溶液pH值、加热、光等对色素稳定性的影响;还进行了色素和副产物的IR分析,红龙果挥发油成分的GC-MS分析;研究表明该色素为水溶性色素,其吸收光谱因pH而异,在pH=4～7、低温、避光条件下稳定性好;副产物为肌醇.     

指甲花色素提取工艺研究

以指甲花色素提取量为评价指标,采用可见分光光度法测定指甲花色素的含量,选取甲醇水溶液的浓度、pH、提取时间和温度四个因素对指甲花提取率的影响,并设计了正交实验进行提取工艺优化研究.结果显示指甲花色素最佳提取工艺条件为:甲醇水溶液的浓度为75%;pH为2;提取时间50min;提取温度70℃.该提取方法简单、方便,为指甲花色素的进一步研究提供依据.     

密闭微波辅助萃取当归粉中的阿魏酸

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.     

缺氧沉积物中重金属形态连续萃取方法的稳定性研究

考察了海水养殖区域缺氧沉积物中重金属形态连续萃取法萃取过程中溶液pH值、温度变化和胶体形成对形态分离结果的影响。结果表明,连续萃取法Step1萃取酸溶态时,萃取液pH值的轻微升高使Pb和Zn的萃取结果明显降低;Step2萃取还原态时,萃取液pH值明显升高对重金属的萃取结果影响很小;Step3萃取有机质结合态时,萃取液pH值的降低对重金属萃取结果影响较小(除Pb外)。由于连续萃取法中各步萃取反应的热力学过程不同,Step1和Step2萃取后溶液温度轻微升高而在Step3中溶液温度稍微降低,溶液温度变化(<2.5℃)对重金属形态的影响很小。在Step1、Step2和Step4萃取过程中胶体的形成和存在,对萃取液Cd、Zn和Cu有明显的吸附影响;而在Step3萃取中萃取剂的分散作用有效控制了溶液中胶体的形成。因此采用连续萃取方法评价沉积物中的重金属形态时,控制萃取液pH值和胶体形成有利于提高萃取结果的稳定性和准确性。     

Effect of Additives on Stability of Waterborne Nanoscale Pigment Red 122 Dispersion

Stability of waterborne nanoscale pigment red 122 dispersion that used copolymer of styrene and maleic acid as modification reagent was affected greatly by additives. In this article, the effects of pH value, ion intensity, and alcohols on centrifugal stability and stability to temperature were investigated. The results showed that pigment 122 dispersion with high centrifugal stability was obtained and the particle size was changed small when treated with different temperature at pH value in the range of 7.70～8.96. Centrifugal stability and stability to temperature were decreased with increasing concentration electrolyte, especially with AlCl₃ and MgCl₂. Alcohols had no negative effect on centrifugal stability and stability to temperature of waterborne nanoscale pigment red 122 dispersion.     

翻白草中熊果酸的微波提取工艺研究

采用单因素实验与正交实验法结合,以提取剂浓度、固液比、微波功率、微波提取时间为考察因素,以熊果酸提取率作为评价指标,优化了熊果酸的微波提取工艺。最优微波提取条件为:90 % 乙醇作为提取剂、料液比1∶20 g/mL、微波功率250 W、微波提取时间120 s。     

Application of synergistic MEHPA-DEHPA mixed solvent to the extraction of lanthanides(III)

The distribution ratio of neodymium(III) in extraction with mono(2-ethylhexyl)-phosphoric acid was determined as a function of extractant and Nd(III) concentrations, and effect of co-existing DEHPA was studied. A characteristic extraction of a tracer quantity of Nd(III) was found at an extractant concentration of approximately 0.01 M. Di(2-ethylhexyl)phosphoric acid depresses the extraction of Nd(III) in MEHPA of a concentration of 0.01M, but enhances it at higher concentrations of MEHPA. Owing to the high Df values against lanthanides(III) and an excellent radiation stability, the synergistic combination of MEHPA-DEHPA, preferably at a DEHPA/MEHPA mole ratio of 3, was concluded to be applicable to the isolation of lanthanides (and actinides) from highly acidic solutions.     

响应面法优化板栗花总黄酮微波提取工艺

应用响应面法优化了乙醇微波提取板栗花中总黄酮的工艺条件。用光度法在波长510 nm处测定提取液中总黄酮的含量(以芦丁为标准),从而判断提取条件的优劣。经试验确定最优提取条件为:①微波功率700 W;②提取时间80 s;③提取溶剂乙醇与水的体积比为40比60;④板栗花料与提取溶剂的比值为1比100。在此选定条件下板栗花总黄酮的提取率达到(3.47±0.14)g/100 g,与理论值(3.49 g/100 g)很接近。     

Study of the adsorption behavior of heavy metal ions on nanometer-size titanium dioxide with ICP-AES

A new method using nanoparticle TiO2 as solid-phase extractant coupled with ICP-AES was proposed for simultaneous determination of trace elements. The adsorption behavior of nanometer TiO2 towards Cu, Cr, Mn and Ni was investigated by ICP-AES, and the adsorption pH curves, adsorption isotherms and adsorption capacities were obtained. It was found that the adsorption rates of the metal ions studied were more than 90% in pH 8.0-9.0, and 2.0 mol L-1 HCl was sufficient for complete elution. Nanometer TiO2 possesses a significant capacity for the sorption of the metal ions studied which is higher than the capacity of silica, the commonly used extractant. The method has been applied to the analysis of some environmental samples with satisfactory results.     

翻白草中鞣质的微波提取工艺研究

采用微波辅助提取方法,以提取剂浓度、pH值、液固比、微波提取时间、温度等为考察因素,并以提取物中总鞣质的提取率为评价指标,使用磷钼钨酸-干酪素分光光度法为定量测定方法,在单因素实验的基础上,通过正交实验优化翻白草中鞣质的提取工艺.实验结果表明,最佳提取条件为:使用70%甲醇作为提取剂、液固比40∶1、提取液pH为8.0、提取温度为40℃、提取时间为10 min.还对翻白草不同部位(根、茎、叶)的鞣质含量进行分析,发现根部中鞣质的含量最大,其次为茎和叶.此外,采用高效液相色谱法对翻白草中鞣质的种类进行定性分析.     

海湾河口表层沉积物中重金属形态连续萃取方法的优化研究

采用单一萃取程序对建立的重金属形态连续萃取方法的萃取条件进行优化.分别以Ca和Mg、Fe、有机质(OM)和酸可挥发性硫(AVS)作为萃取剂释放酸溶态、还原态、有机质结合态和硫化物结合态等重金属目标形态的表征参量,考察萃取剂对相应目标形态的萃取能力和选择性.分别根据表征参量和重金属在萃取溶液中的含量变化确定最优萃取时间和萃取样液比.结果表明,优化萃取条件后,萃取剂对目标形态重金属均有很强的释放能力.酸溶态萃取剂对其它非残留态影响很小;还原态萃取剂除对酸溶态有少量提取外,对其它形态影响较小;有机质结合态萃取剂对硫化物结合态有少量萃取,对其它形态影响较小.硫化物结合态在酸溶态、还原态和有机质结合态之后萃取,避免了对这三种形态的影响.优化后的连续萃取方法对重金属形态有较好的选择性,可对海湾和河口表层沉积物中重金属的目标形态进行较为合理地分离和评价.     

Polyphosphate interaction with aluminium-doped titania pigment particles

The interaction of a widely used Calgon™ polyphosphate dispersing reagent with aluminium-doped titania pigment particles has been investigated using electrokinetic and rheological studies combined with adsorption isotherms. The influence of pH, aluminium dopant concentration and polyphosphate concentration is reported. Polyphosphate adsorption density and affinity with the titania pigment surface is highest under acidic solution conditions. This however, does not necessarily transfer to enhanced dispersion properties at low pH values. At pH 9, the polyphosphate adsorption density correlates directly with a reduction in pigment particle interactions making polyphosphate an effective titania pigment dispersant under alkaline conditions. Conversely, at pH 4, polyphosphate adsorption densities less than 0.1 mg m⁻² have no effect on the colloidal stability of the titania particles and their Newtonian flow behaviour. At adsorption densities of 0.1 mg m⁻², approaching the iep (near 0.2 mg m⁻²), the suspension aggregates. It is not until the polyphosphate adsorption density is greater than 0.3 mg m⁻² that the titania pigment suspension begins to restabilise. It is proposed that chemisorption dominates polyphosphate adsorption at pH 9 whilst at pH 4 a combination of chemisorption and electrostatic adsorption occurs. Stabilisation by the polyphosphate present at the pigment surface depends on both electrostatic and steric effects. At high pH, both are effective but at low pH, electrostatic stabilisation is partly neutralised and higher adsorption densities are required for effective stabilisation.