从RNA酶解液中分离5-尿苷酸

采用2根强酸性阳离子交换柱、1根弱碱性阴离子交换柱和1根强碱性阴离子交换柱进行4柱串联,可以从RNA酶解液中分离得到5-尿苷酸,而不混有其它核苷酸,并对离子交换树脂种类、树脂量、洗脱剂等作了进一步研究。结果表明,采用4柱串联分离5-尿苷酸,其总收率达到92．1％、结晶纯度达到86％以上。     

离子交换法分离DMF溶液中低浓度甲酸性能的研究

采用离子交换树脂分离DMF中低浓度甲酸溶液,筛选出D301树脂,分别考察了其在静态交换和动态交换中的分离性能。结果表明,在静态交换温度35℃,振荡速度160 r/min,树脂浓度30 g/L时,树脂平衡交换量为11.55 mg/g。高径比为2∶1的离子交换柱,在35℃、溶液流速5 mL/min条件下,对甲酸含量586 mg/L的甲酸-DMF溶液的动态交换和连续循环交换均具有很好的交换性能。     

从RNA酶解液中分离5'-尿苷酸

采用2根强酸性阳离子交换柱、1根弱碱性阴离子交换柱和1根强碱性阴离子交换柱进行4柱串联,可以从RNA酶解液中分离得到5'-尿苷酸,而不混有其它核苷酸,并对离子交换树脂种类、树脂量、洗脱剂等作了进一步研究.结果表明,采用4柱串联分离5'-尿苷酸,其总收率达到92.1％、结晶纯度达到86％以上.     

从RNA酶解液中分离5'-尿苷酸

采用2根强酸性阳离子交换柱、1根弱碱性阴离子交换柱和1根强碱性阴离子交换柱进行4柱串联,可以从RNA酶解液中分离得到5'-尿苷酸,而不混有其它核苷酸,并对离子交换树脂种类、树脂量、洗脱剂等作了进一步研究.结果表明,采用4柱串联分离5'-尿苷酸,其总收率达到92.1％、结晶纯度达到86％以上.     

离子交换树脂对高麦芽糖浆的分离纯化研究

研究了离子交换树脂分离纯化高麦芽糖浆的新工艺。利用离子交换树脂吸附分离法,通过液相色谱测定分离前后的麦芽糖含量,选出了较适合的732型离子交换树脂进行了交换柱吸附分离提纯实验。研究了温度、流速、进样量及二次分离对分离效果的影响,较适宜的分离条件是柱温为70℃,流速为2ml／min,进样量为10d,经二次分离后,麦芽糖含量达到90．75％。结果表明,732型离子交换树脂对高麦芽糖浆中的低聚糖具有较好的分离效果。     

离子交换色谱法分离硼同位素的研究进展

综述了离子交换色谱法分离硼同位素的进展。在目前的研究方法中,主要采用强碱性阴离子交换树脂、弱碱性阴离子交换树脂和硼特效树脂作为柱填充材料,本文对于这3种树脂的优缺点进行了比较,最后对影响单级分离因子的因素进行了讨论。表明离子交换色谱法是一种极具潜力的硼同位素分离方法,具有高效节能的特点。     

高硅铝比钾离子筛的合成及其对K+的交换性能

以NaA1O2、水玻璃为原料,KOH为碱源,利用水热法合成了高硅铝比钾离子筛.考察了硅铝比、碱度、模板剂、晶化温度和晶化时间对钾离子筛晶相结构、产率和交换容量的影响,通过X射线衍射、化学组成分析、扫描电镜、热重差热分析、Fourier红外光谱对样品进行了表征.结果表明:以四丁基溴化铵为模板剂,物质的量比为6.68K2O:19.3SiO2:1Al2O3:624H2O,120℃条件下合成12 h,获得的高硅铝比钾离子筛为钾型钙十字沸石,化学组成为Si21Al5.1K2.4Na2O55·8H2O;离子筛对纯钾溶液和海水中钾离子的交换量分别达123·22 mg/g和56.96 mg/g,对K+/Na+的选择性系数为95.46,可用于从海水中选择性分离钾盐.     

吸附分离二甲苯分子筛的改性条件研究

采用13X型沸石分子筛作为改性对象，用填充柱分离色谱考察了混合二甲苯的分离效果，通过钾、钡离子的单独改性和复合改性的研究表明，钾离子的交换优于钡离子，复合改性的分子筛的分离效果优于单种离子。     

D296树脂分离锆、铪洗脱的效果

介绍了在离子交换固定床上用D296强碱性阴离子交换树脂分离锆、铪的洗脱实验研究。吸附与洗脱实验的温度均控制在2~5℃,洗脱实验在饱和吸附的离子交换柱、过漏的离子交换柱、未过漏的离子交换柱中进行。研究结果表明:离子交换柱吸附状态以及洗脱剂酸度对分离效果有显著的影响。当离子交换柱存在交换区时,用任何酸度的硫酸作为洗脱剂,铪均被先洗脱出来,但高酸度的洗脱剂对分离锆、铪更有利;当离子交换柱为饱和状态时,低酸度和高酸度的洗脱剂洗脱,锆、铪不能得到分离。实验证明了单一的固定床分离锆、铪的效率低,要成功实现锆、铪的分离,需采用连续分离的离子交换移动床。     

四丁基氢氧化铵的合成

采用凝胶型强碱性阴离子交换树脂与四丁基溴化铵溶液进行离子交换制取四丁基氢氧化铵溶液,考察了适宜的合成工艺条件。结果表明,四丁基溴化铵的浓度为27.0%,温度为15℃,再生液NaOH浓度为5.0%,交换柱内离子交换树脂的高径比为15时,交换度大于86.0%,产品(C4H9)4NOH(四丁基氢氧化铵)的溶液浓度大于10.0%。方法简单,离子交换树脂可再生。     

水溶性两性高分子的合成和溶液性质

等物质的量的二甲胺和氯丙烯在碱性条件下反应生成烯丙基二甲胺 ,转化率为 6 8 7%;烯丙基二甲胺与氯乙酸钠〔n(烯丙基二甲胺 )∶n(氯乙酸钠 ) =1∶0 8〕在 6 0～ 70℃进行季铵化反应 ,合成了两性离子单体N 羧甲基 N ,N 二甲基 N 烯丙基氢氧化铵内盐 (CDAH) ,转化率 96 5 %(以氯乙酸钠计 )。以水为溶剂 ,亚硫酸氢钠和过硫酸钾为引发剂 ,合成了N 羧甲基 N ,N 二甲基 N 烯丙基氢氧化铵内盐—丙烯酰胺 (AA)两性共聚物 ;聚合条件为 :聚合温度 6 0～ 80℃ ,单体量比n(CDAH)∶n(AA) =3∶7,单体的质量分数w (CDAH +AA) =30 %,引发剂NaHSO3 和K2 S2 O8的质量均为单体总质量的 0 2 %。研究了两性高分子在不同介质中的黏度特性。结果表明 ,两性共聚物的等电区 (pH值 )为 5 5～ 7 5 ;非等电区时共聚物在纯水中具有典型的聚电解质黏度特性 ,随外加盐阴离子半径的增大 ,或随盐溶液浓度的增大 ,比浓黏度和特性黏度减小 ,Huggins常数增大 ;等电区时共聚物在纯水中的黏性行为符合Mark Huggins方程 ,外加盐的影响与非等电区时相反。     

Photochemical formation of palladium patterns on surface-modified polyimide resin

A simplified method for forming a palladium circuit pattern on polyimide resin substrate was proposed. The carboxyl group, as a cation exchange group, was formed on the polyimide resin surface by a potassium hydroxide treatment. Palladium(II) ion was then adsorbed onto the surface modified polyimide resin by ion exchange. Ultraviolet irradiation of this palladium(II) ion absorbed resin with sodium formate coated on its surface resulted in the formation of a palladium thin film. Irradiation through a metal-on-quartz mask onto the modified polyimide resin surface photoreduced the palladium ion into metallic palladium circuit patterns easily without using a plating resist.     

INNOVATIVE APPROACHES TO SYNTHESIS OF GT 267-004, A SEQUESTRANT FOR C. DIFFICILE TOXIN

GT 267-004 is a nonabsorbed, nonantibiotic, high molecular weight anionic polymer that is undergoing clinical evaluation as a Clostridium difficile toxin sequestrant. The active pharmaceutical ingredient (API) is a mixed salt form that consists of approximately 30 to 50% potassium and 70 to 50% sodium as the counterions on the polymer. The initial polymerization process results in an aqueous polymer solution with the polymer in the 100% sodium form. This article describes the use of two innovative approaches, electrodialysis (ED) and ion exchange using ion exchange resins (IXR), to convert the single-salt polymer to the mixed-salt form. Electrodialysis experiments were conducted using a stack of five cells, each of which contained two cation and one anion exchange membranes. The electrodialysis was run in batch mode with a sodium chloride solution as the concentrate stream and a potassium chloride solution as the diluate stream. The ED process was monitored on-line by measuring the conductivity of the streams. Yield loss of the API through the ED membranes was minimal. The ED process was found to be fast, efficient, and reproducible. The ion exchange experiments were conducted using a strong acid cation resin in the potassium form. By using a fixed bed column mode, an appropriate amount of ion exchange was carried out to produce the mixed-salt API in the effluent stream. The resin bed could be regenerated using KCl solution and reused for subsequent batches of polymer solution. The recovery of the API in the product solution was excellent. The ion exchange route was used to synthesize radio-labeled API for clinical trials.     

INNOVATIVE APPROACHES TO SYNTHESIS OF GT 267-004, A SEQUESTRANT FOR C. DIFFICILE TOXIN

GT 267-004 is a nonabsorbed, nonantibiotic, high molecular weight anionic polymer that is undergoing clinical evaluation as a Clostridium difficile toxin sequestrant. The active pharmaceutical ingredient (API) is a mixed salt form that consists of approximately 30 to 50% potassium and 70 to 50% sodium as the counterions on the polymer. The initial polymerization process results in an aqueous polymer solution with the polymer in the 100% sodium form. This article describes the use of two innovative approaches, electrodialysis (ED) and ion exchange using ion exchange resins (IXR), to convert the single-salt polymer to the mixed-salt form. Electrodialysis experiments were conducted using a stack of five cells, each of which contained two cation and one anion exchange membranes. The electrodialysis was run in batch mode with a sodium chloride solution as the concentrate stream and a potassium chloride solution as the diluate stream. The ED process was monitored on-line by measuring the conductivity of the streams. Yield loss of the API through the ED membranes was minimal. The ED process was found to be fast, efficient, and reproducible. The ion exchange experiments were conducted using a strong acid cation resin in the potassium form. By using a fixed bed column mode, an appropriate amount of ion exchange was carried out to produce the mixed-salt API in the effluent stream. The resin bed could be regenerated using KCl solution and reused for subsequent batches of polymer solution. The recovery of the API in the product solution was excellent. The ion exchange route was used to synthesize radio-labeled API for clinical trials.     

Synthesis and cation exchange properties of a new porous cation exchange resin having an open-celled monolith structure

We succeeded in introducing cation exchange groups quantitatively into a porous resin having an open-celled monolith structure. The resulting new cation exchange resin had the following advantages compared with conventional ion exchange resins having a bead structure. First, it was easier to pack it in a column. Second, the ion exchange rate of the new cation exchange resin was much higher than that of the conventional ion exchange resins, and the ion exchange band length of the new resin was smaller than that of the conventional ones. In addition, the electric conductivity was about five times higher than that of the conventional ones, although they had similar ion exchange capacities. These unique properties of the new cation exchange resin were caused by the quantitative introduction of ion exchange groups into the resin having the open-celled monolith structure.     

离子交换法碳酸钾含氨氮生产废水的处理工艺改进

采用离子交换法生产碳酸钾时,低浓度含氨氮废水的回收是主要难题。选择性能稳定、工作交换容量大的交换树脂,可提高树脂和盐酸的利用效率,降低运行成本。采用半连续离子交换和解吸液循环增浓套用技术,可使树脂利用率提高30%,氯化铵提升到150 g/L以上,盐酸利用率96%。该技术不仅解决了氯化铵含氨氨废水的污染难题,同时也为副产盐酸找到合理的出路,经济和环保效益显著。     

Purification of glycerol/water solutions from biodiesel synthesis by ion exchange: sodium and chloride removal. Part II

BACKGROUND: Equilibrium studies were carried out with the aim of finding the basic design parameters for ion exchange plants using a glycerol phase obtained from biodiesel production. The uptake of sodium and potassium ions on a strongly acidic ion exchanger, Amberlite IR‐120, in the proton form from glycerol/water mixtures has been studied. The effect on the selectivity towards sodium of the percentage of water in glycerine/water mixtures on the macroporous resin Amberlite 252 has been analyzed. Finally, chloride removal by a strongly basic anionic‐exchange resin Amberlite IRA‐420 at three different temperatures has been studied. RESULTS: The strongly acidic ion exchanger Amberlite IR‐120 exhibits higher selectivity for potassium versus sodium ions. The ideal mass action law model was able to fit the experimental equilibrium data. The equilibrium data obtained at different percentages of water in the glycerine/water mixture indicate that as the water content increased the resin selectivity for sodium uptake is reduced. The selectivity of the anion exchange resin Amberlite IRA‐420 for chloride ions decreases with temperature. The ideal mass action law was accurate enough to fit the equilibrium data of the three systems and allowed the equilibrium thermodynamic properties to be obtained. CONCLUSIONS: These results confirm that macroporous resin Amberlite 252 could be a good choice to remove sodium ions from glycerol/water solutions with a high salt concentration and also that a strongly basic anionic‐exchange resin could be used for chloride removal. Copyright © 2009 Society of Chemical Industry     

国内催化合成草酸二丁酯的进展

评述了对甲苯磺酸,对甲苯磺酸铜,氨基磺酸,强酸性阳离子交换树脂,六水三氯化铁,固载三氯化铝,五水四氯化锡,硫酸铜,七水硫酸锌,氧化钐,一水硫酸氢钠,硫酸氢钾,固体超强酸,杂多酸和维生素C等催化剂催化合成草酸二丁酯的合成方法。认为固载对甲苯磺酸,对甲苯磺酸铜,氨基磺酸,强酸性阳离子交换树脂,活性碳固载四氯化锡,氧化钐,一水硫酸氢钠,硫酸氢钾,固体超强酸,杂多酸和维生素C是合成草酸二丁酯的良好催化剂。微波辐射是有机合成的良好方法。     

Evaluation of a Bidisperse Pore Model for Ion Exchange Kinetics in Porous Media

A previously published bidisperse pore model that considers in turn ion interdiffusion in macro- and micro-pores as competitive and step-by-step processes was evaluated. The ion exchange rate of H⁺/Ni²⁺ on gel and macroporous strong acid resins was measured under conditions favoring a particle diffusion controlled mechanism. The interdiffusion coefficients were obtained using a bidisperse pore and quasi-homogenous resin phase kinetic models, respectively. The overall rate of H⁺/Ni²⁺ exchange on the macroporous resin is lower than in the gel resin. It was shown that ion interdiffusion in the micropores of the porous resin could also be important.     

电去离子技术再生化学镀镍老化液的研究

采用电去离子技术去除化学镀镍老化液中残余的Ca2+,考察了不同工艺条件对Ca2+的去除率的影响。结果表明:随着电流的增加,Ca2+的去除率增大;凝胶型阳树脂比大孔型阳树脂更有利于对Ca2+的去除。在实验所用电流条件下,溶液的pH值在酸性范围内,同时对EDI膜堆进行了改造,增加极室保护室,避免了膜堆结垢。