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索氏提取法制备高纯度色酮 总被引:1,自引:0,他引:1
采用索氏提取法制备了高纯度色酮。以提取率和纯度为指标,考查了溶剂、石油醚与色酮用量比(简称液料比)、虹吸次数、温度及提取次数对提取效果的影响。结果表明,最佳的提取条件为:石油醚(沸点30~60℃)为溶剂、液料比30∶1、虹吸15次、45℃、提取1次,此时色酮的提取率为98.5%,产物色酮的纯度大于99.0%。 相似文献
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浓盐法和稀碱法提取啤酒废酵母核糖核酸的比较 总被引:3,自引:0,他引:3
通过正交实验对浓盐法和稀碱法提取啤酒废酵母核糖核酸进行了比较.结果表明,浓盐法的适宜提取条件为:NaCl质量分数15%、提取时间5 h、提取温度90℃、酵母质量分数8%,此条件下核糖核酸的提取率为6.82%、纯度为85.45%;稀碱法的适宜提取条件为:NaOH质量分数0.6%、提取时间50 min、酵母质量分数10%、沉淀温度4℃,此条件下核糖核酸的提取率为12.14%、纯度为53.71%.浓盐法虽然提取率低于稀碱法,但产品纯度高,而稀碱法的提取时间短,更利于工业化生产. 相似文献
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两种提取枸杞多糖方法的比较研究 总被引:2,自引:0,他引:2
通过正交实验对热水浸提法和微波提取法提取枸杞多糖进行了比较研究。热水浸提法提取枸杞多糖的最佳工艺条件为:提取温度70℃、提取时间4h、料液比1∶20(g∶mL)、提取次数3次,提取率为4.51%;微波提取法提取枸杞多糖的最佳工艺条件为:微波功率560W、微波时间90s、料液比1∶10(g∶mL)、提取次数3次,提取率为5.91%。微波提取法时间短、能耗小、提取溶剂用量少、提取率高,优于热水浸提法。 相似文献
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赶黄草中槲皮素的提取工艺研究 总被引:1,自引:0,他引:1
目的:优选赶黄草中槲皮素的提取工艺。方法:分别用回流提取法、超声提取法和冷浸法,提取赶黄草中的槲皮素。回流法采用单因素试验分别考察回流时间、乙醇浓度对提取率的影响;超声提取法采用单因素试验分别考察超声时间、乙醇浓度对提取率的影响;冷浸法考察乙醇浓度对提取率的影响;以槲皮素提取率为指标,提取率越高,提取工艺效果越好;用紫外分光光度法对不同提取工艺中槲皮素的含量进行测定。结果:超声法最佳提取工艺为:80%的乙醇超声提取30 min,回流法最佳提取工艺为:80%的乙醇回流提取4 h;冷浸法最佳提取工艺为:80%的乙醇浸渍36 h。结论:回流法提取赶黄草中槲皮素的提取率最高。 相似文献
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正交实验优化异甘草素超声提取工艺 总被引:2,自引:0,他引:2
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。 相似文献
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Sei Kwang Hahn Hee Wook Ryu Yong Keun Chang 《Korean Journal of Chemical Engineering》1998,15(1):51-55
The recovery of poly(3-hydroxybutyrate) [PHB] fromAlcaligenes eutrophus and a recombinantEscherichia coli strain harboring theA. eutrophus poly(3-hydroxyalkanoates) biosynthesis genes was studied. When PHB was recovered using sodium hypochlorite or sodium dodecyl
sulfate (SDS), non-PHB cell materials (NPCM) of the recombinantE. coli seemed to be more easily digested than those ofA. eutrophus. Furthermore, viscosity increase caused by cell lysis during SDS treatment was negligible for the recombinantE. coli, whereas a very viscous suspension was formed forA. eutrophus. These results, together with our previous finding that PHB in the recombinantE. coli is far less susceptible to molecular degradation by sodium hypochlorite, suggested that the recombinantE. coli was more beneficial than A.eutrophus in terms of PHB recovery. In order to develop an easy and efficient recovery process, we adopted and optimized the SDS treatment
since, with the hypochlorite treatment, we could not handle high biomass concentrations effectively. We could obtain a PHB
of 95 % purity with 96 % recovery under the optimal condition of a biomass concentration of 5 %, a ratio of SDS to biomass
of 0.6, a treatment time of 60 minutes, and a treatment temperature of 30°C. 相似文献
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Study on Kinetics of Dissolving Biomass Using Sodium Hypochlorite in the Recovery of Poly- β-hydroxybutyrate
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1 INTRODUCTIONSodium hypochlorite has been widely used to separate poly-β-hydroxybutyrate(PHB)becauseit can digest nearly all components of the cell.But sodium hypochlorite also attacks thePHB granu1es and thus reduces the relative molecular mass of the PHB.A new process using adispersion of sodium hypochlorite solution and chloroform for the recovery of PHB was developedby Hahn et al.In this process,sodium hypochlorite digested the cell wall and released the PHB 相似文献
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引言聚-β-羟基丁酸酯(PHB)是微生物合成的一种高分子聚合物,它具有可生物降解性等特性,近年来深受世人瞩目.但由于PHB以颗粒状态存在于细胞中,因此分离提取很困难,生产成本很高.目前从微生物细胞中分离PHB的方法有溶剂萃取法、化学试剂法和酶法.虽然用次氯酸钠破细胞壁来分离PHB的化学试剂法操作简单、效率高,但次氯酸钠会引起PHB分子的严重降解,因此目前仍以溶剂萃取法和酶法为主.但这两种方法分别具有溶剂用量大和分离效率低的缺点.日本学者报道了用1%的油酸钠在120℃作用于菌体20min纯化PHB的方法.Ramsay等人先… 相似文献
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Salwa O. Heikal Atef A. Ibrahem 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1978,28(10):671-676
Bleaching of rice straw soda pulp was investigated under various conditions. The rate of the chlorination and hypochlorite reactions were studied; the best properties were attained by shortening the chlorination time to about 20 min. The extraction efficiency of ammonium hydroxide on chlorinated soda pulp was also investigated. The effectiveness of extraction can be deduced from the reduction of the kappa number, cuprammonium viscosity and the brightness obtained after the hypochlorite step. Extraction can be carried out with ammonium hydroxide instead of sodium hydroxide used in the conventional method. The strengths of unbleached and fully bleached pulps were evaluated. The fully bleached ammonium hydroxide extracted pulps were beaten faster and were usually stronger than the corresponding pulps extracted with sodium hydroxide. 相似文献
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将2-氯甲基-3,4-二甲氧基吡啶盐酸盐与5-二氟甲氧基-2-巯基-1H-苯并咪唑在碱性水溶液中反应制得中间体,直接将其萃取至二氯甲烷中,然后用NaClO进行氧化,接着成盐、精制得到泮托拉唑钠。研究了氧化反应温度、氧化剂用量及滴加速度对泮托拉唑纯度的影响,得出了较佳的氧化反应条件。在此条件下泮托拉唑钠的纯度可达99.7%以上,总收率可达78.3%。 相似文献
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Ni2O3催化剂的制备及其催化NaClO分解产生活性氧的性能 总被引:1,自引:0,他引:1
采用混合法制备Ni2O3催化剂选择性催化次氯酸钠分解生成原子氧,该原子氧具有极强的活性,能增强次氯酸钠的氧化性。采用XRD、SEM、BET等方法对催化剂的物化性质及催化性能进行了研究,同时考察了不同负载量催化剂、次氯酸钠浓度、pH值和温度对镍基催化剂分解次氯酸钠产生活性氧的反应速率的影响。实验结果表明,次氯酸钠溶液浓度与反应速率成正比;而对于pH值来说,中性或弱酸性环境更有利于提高反应速率和产氧量;温度越高分解反应速率越快。在初步处理有机废水的实验中,甲醇、甲苯、间氨基苯磺酸COD的去除率分别达到91.3%、89.28%和84.53%。 相似文献
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次氯酸钠具有强氧化性,但因性能极不稳定,大大降低了其氧化性能的利用率。采用混捏法制备改性的镍基催化剂催化氧化次氯酸钠,生成的原子氧具有极强的活性,特别是在次氯酸钠浓度不高时,可大大提高次氯酸钠的氧化性能和利用率。采用混捏法制备的改性镍基催化剂用于催化分解次氯酸钠产生活性氧。通过FT-IR、SEM和BET等方法对催化剂的物化性能及催化性能进行了研究,考察了改性镍基催化剂催化分解次氯酸钠溶液反应动力学和活性氯的变化情况。结果表明,添加Fe2O3的镍基催化剂具有较高的活性,在改性镍基催化剂作用下,反应活化能大大降低,次氯酸钠活性氯的转化率达到90%以上。在初步处理有机废水的实验中,COD的去除率达到92.5。 相似文献