Expanded Bed Adsorption Chromatography for Recovery of Phycocyanins from the Microalga Spirulina Platensis

We carried out the purification of C-phycocyanin and allophycocyanin from Spirulina platensis taking advantage of the adsorption properties of the expanded beds. Initially, phycobiliproteins were released from the microalga cells by osmotic shock. Next, phycocyanins were recovered by applying the centrifuged cell suspension directly to the anion exchanger Streamline-DEAE using expanded bed columns, equilibrated with 50 mM sodium phosphate buffer, pH 7.0. After adsorption, washing was carried out in the expanded-bed mode. Having removed unbound proteins and cellular debris, the bed was allowed to sediment and phycocyanins rich solution was eluted with a downward flow of 500 mM sodium phosphate buffer, pH 7.0. Finally, we utilized conventional gel filtration and ion exchange chromatography methods for separation and purification of C-phycocyanin and allophycocyanin. The purification steps were monitored using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the purity of recovered phycocyanins was confirmed by absorption and emission spectroscopy. The main advantage of this new method is the high yield achieved in the steps of product extraction and adsorption by expanded bed adsorption, so reducing both processing times and costs.     

Expanded Bed Chromatography as a Tool for Nanoparticulate Separation: Kinetic Study and Adsorption of Protein Nanoparticles

Expanded bed adsorption was investigated together with its suitability for the practical recovery of nanoparticulate mimics of products such as plasmid DNA and viruses as putative gene therapy vectors. The study assessed the binding of protein nanoparticles fabricated from bovine serum albumin (BSA) with average size of 80 nm as a model system and viral size/charge mimic to the streamline DEAE adsorbent in the expanded bed column chromatography. The adsorption kinetics and adsorption mechanism for the BSA nanoparticles on the adsorbent were studied. In batch adsorption studies, the factors nanoparticle concentration, contact time and adsorbent amount, affecting adsorption isotherms were investigated. Subsequently the data were regressed against the Lagergren equation, which represents a first-order kinetics equation and also against a pseudo-second-order kinetics equation. The results demonstrated that the adsorption process followed a Langmuir isotherm equation. The kinetics of the adsorption process followed a pseudo-second-order kinetics model with a rate constant value of 0.025 g mg^?1 min^?1. The dynamic binding capacity of the BSA nanoparticles on an expanded bed was calculated. The recovery of the nanoparticles was more than 85%.     

扩张床吸附基质研究进展

针对扩张床吸附这一新型蛋白质分离纯化技术，论述了吸附剂基质对该项技术应用的重要性，并且评述了近十年来扩张床吸附基质的研究状况，在此基础上重点介绍了基质所需的特性、常用的扩张床基质及其制备方法。     

球形氧化锆液相色谱柱填料的制备和评价

采用改进油乳液-溶胶-凝胶法制备了不同粒径的色谱用氧化锆微球。用X射线衍射、扫描电镜、比表面测定仪进行了结构、比表面积、孔径、孔体积和形貌表征。讨论了影响颗粒大小和颗粒分布均匀的制备因素。实验证明:有机相性质、有机相与水相的体积比、乳化剂的性质和浓度、助乳化剂的存在、搅拌速度是决定最终制备氧化锆颗粒大小和均匀的主要因素。     

Preparation and Characterization of a Novel Spherical Cellulose Adsorbent for Reduction Adsorption of Trichloroacetic Acid

A novel spherical cellulose adsorbent has been prepared by homogeneous graft polymerization of N,N＇-methylenebisacrylamide （MBA） onto cellulose in an ionic liquid, 1-N-butyl-3-methylimidazolium chloride （BMIMC1）, which was then partially amine methylated through Mannich reaction to get bifunctionalized materials containing both amide and sulphinate moities. Factors affecting the attachment of functional groups were investigated. The adsorbent was characterized by Elemental Analysis （EA）, Fourier Transform Infrared Spectroscopy （FTIR） and Scanning Electron Microscope （SEM）. Cellulose adsorbent was then tested for its potential applications in the reduction adsorption oftrichloroacetic acid （TCAA） from aqueous solutions.     

Synthesis and Characterization of Yttria-Stabilized Zirconia (YSZ) Nano-Clusters for Thermal Barrier Coatings (TBCs) Applications

Yttria-stabilized zirconia (YSZ) nano-clusters were synthesized by a sol–gel process. The aim was to produce YSZ powders in order to prepare thick coatings for thermal barrier to be applied on gas turbine engine components. Yttrium nitrate hexahydrate and zirconium oxy-chloride octahydrate were used as a source of zirconium, citric acid was taken as a chelating agent, and ethylene glycol was used as a polysterification agent. The synthesized powders were characterized by X-ray diffraction, transmission electron microscopy, thermo-gravimetric analysis and differential scanning calorimetry, and Raman spectroscopy. Furthermore, parameters were critically analyzed in order to synthesize non-transformable (t′) tetragonal crystal structure, which is the best zirconia phase for high temperature thermal barrier coatings applications. In this regard, tetragonal YSZ nano-clusters were heated in an alumina crucible at a temperature of 1200 °C for 100 h.     

Adsorption Strategy of Plasmid DNA Nanoparticulate: Preparative Purification by a Simple Custom Expanded Bed Column

This paper summarizes the critical examination of the hydrodynamic performance of the NBG expanded bed contactor operated with streamline-DEAE adsorbent under various operating conditions for expanded bed adsorption of plasmid DNA nanoparticles from alkaline lysate. The purification process is not RNase-free. In this study, a rapid and efficient scaleable purification protocol obtaining, plasmid DNA nanoparticles (average size of 40 nm) with a high purity level for use as therapeutic agent in customized NBG expanded bed columns was developed. This technique allows efficient levels of binding to the column media and vector purification without centrifugation or filtration steps. Residence time distribution (RTD) studies were exploited to achieve the optimal condition of plasmid DNA nanoparticle (pDNA) recovery upon anion exchange adsorbent in this contactor. In addition, the purification experiments were carried out in the expanded bed columns with settle bed height of 6.0 ± 0.2 cm. NaCl gradient elution enabled the isolation of supercoiled plasmid from low-Mr RNA, cDNA and plasmid variants. Subsequently dynamic binding capacity of the adsorbent was calculated while these values decreased with increase in flow velocity. Moreover, the effect of pH upon the performance of this recovery process and the feedstock volume upon the expanded bed anion exchange purification was investigated. The results demonstrated that separation of low-Mr RNA from plasmid DNA isoforms in the range of pH between 5.5 and 7.5 is achievable in this column. The yield of recovery of pDNA in optimal condition was higher than 88.51% which was a superior result in one-pass frontal chromatography. The generic application of simple customized NBG expanded bed column and its potential for the purification and recovery of plasmid DNA as a nanoparticulate bioproduct is strongly discussed.     

Hydrodynamic Characteristics and Adsorption Particularity of Nanobiological Feedstock Along the Bed Height in a Novel Chromatography Column

Expanded bed adsorption (EBA) is a practical method for the separation of nanoparticulates. In order to analysis the local hydrodynamic and adsorption behavior of nanoparticle (NP)-based biological feedstock, a modified Nano Biotechnology Group EBA column with a 26-mm inner diameter was used to withdraw liquid from different axial positions of the column. Fabricated egg albumin (EA) NPs with an average size of 70?nm were employed as a model system and viral size/charge mimic to assess the relationship between hydrodynamic and adsorption performance of NPs at the different column regions. The effects of influential factors, including flow velocity and initial concentration of NPs, on NP hydrodynamic behavior and adsorption kinetics along the bed height were investigated. NP hydrodynamic studies confirmed that non-uniform behavior dominated the system and a decreasing trend of liquid mixing/dispersion with increase of bed height was observed in this column. The results demonstrated an increase in the mixing/dispersion at certain bed heights with the increase in both the velocity and feed initial concentration. Breakthrough curves were measured at various column points to determine the adsorption performance [dynamic binding capacity (DBC) and yield] in different bed positions/zones. Yield and DBC of NPs were improved along the bed height, whereas liquid velocity had the opposite effect. Increasing the initial concentration of NPs enhanced only the DBC. Separation of EA NPs under optimal conditions was 87?%, which is an excellent result for a one-pass frontal chromatography method.     

Hydrodynamic Characteristics and Adsorption Particularity of Nanobiological Feedstock Along the Bed Height in a Novel Chromatography Column

Expanded bed adsorption (EBA) is a practical method for the separation of nanoparticulates. In order to analysis the local hydrodynamic and adsorption behavior of nanoparticle (NP)-based biological feedstock, a modified Nano Biotechnology Group EBA column with a 26-mm inner diameter was used to withdraw liquid from different axial positions of the column. Fabricated egg albumin (EA) NPs with an average size of 70 nm were employed as a model system and viral size/charge mimic to assess the relationship between hydrodynamic and adsorption performance of NPs at the different column regions. The effects of influential factors, including flow velocity and initial concentration of NPs, on NP hydrodynamic behavior and adsorption kinetics along the bed height were investigated. NP hydrodynamic studies confirmed that non-uniform behavior dominated the system and a decreasing trend of liquid mixing/dispersion with increase of bed height was observed in this column. The results demonstrated an increase in the mixing/dispersion at certain bed heights with the increase in both the velocity and feed initial concentration. Breakthrough curves were measured at various column points to determine the adsorption performance [dynamic binding capacity (DBC) and yield] in different bed positions/zones. Yield and DBC of NPs were improved along the bed height, whereas liquid velocity had the opposite effect. Increasing the initial concentration of NPs enhanced only the DBC. Separation of EA NPs under optimal conditions was 87 %, which is an excellent result for a one-pass frontal chromatography method.

     

新型吸附剂的合成、表征及其对Ni(II)的吸附研究

利用滴加法合成了球形含Ni2 交联壳聚糖,并通过胺化引入大量活性氨基,再经除镍制成对重金属镍离子具有较好吸附能力的新型吸附剂[P-C-CTS(Ni)].通过Ni2 吸附容量的测定,IR及XPS分析,验证了合成技术路线的正确性.通过研究pH值对吸附量的影响,初步讨论了无柠檬酸根(Cit)配位体存在时,吸附剂对Ni(II)的吸附为螯合作用.通过Cit存在条件下(cNi=cCit=0.852mmol·L-1),吸附剂对Ni(II)离子和Cit的吸附量随pH值的变化,结合相应pH值下金属镍的形态分布,探讨了其对Ni(II)的吸附机理,研究认为不仅仅是简单的螯合作用,其吸附机理和吸附量与溶液中金属离子的存在形式有关,引入静电吸附原理解释了吸附剂对Ni(II)的吸附现象.     

新型吸附剂的合成、表征及其对Ni(II)的吸附研究

利用滴加法合成了球形含Ni^2＋交联壳聚糖, 并通过胺化引入大量活性氨基, 再经除镍制成对重金属镍离子具有较好吸附能力的新型吸附剂[P-C-CTS(Ni)]. 通过Ni^2＋吸附容量的测定, IR及XPS分析, 验证了合成技术路线的正确性. 通过研究pH值对吸附量的影响, 初步讨论了无柠檬酸根(Cit)配位体存在时, 吸附剂对Ni(II)的吸附为螯合作用. 通过Cit存在条件下(c_Ni＝c_Cit＝0.852 mmol•L^－1), 吸附剂对Ni(II)离子和Cit的吸附量随pH值的变化, 结合相应pH值下金属镍的形态分布, 探讨了其对Ni(II)的吸附机理, 研究认为不仅仅是简单的螯合作用, 其吸附机理和吸附量与溶液中金属离子的存在形式有关, 引入静电吸附原理解释了吸附剂对Ni(II)的吸附现象.     

新型气相色谱检测器研制

气相色谱仪是近年来分析测试应用最广泛的仪器之一,气相色谱常用的热导检测器(TCD)应用面广,但灵敏度偏低,且热丝易于烧断,氢焰检测器(FID)灵敏度较高,却对多数无机气体无响应,且必须配备氢气源,使用中具有一定危险性,两者各有局限,为此,研究一种应用广泛,使用简便,高灵敏的气相色谱检测器,已成为广大色谱工作者长期研究的课题。本文所介绍的一种新型气相色谱检测器用催化元件配以专门设计的气路和电路组成,可与现行一些气相色谱仪匹配使用,已成功地进行了许多有机组分及无机气体的分析。1　检测原理汽化后的有机蒸汽或无机可燃气体…     

Binary Adsorption of Phenol and m-Cresol Mixtures onto a Polymeric Adsorbent

Adsorption processes are gaining interest as methods of purifying industrial effluents. Most industries discharge effluents containing several components. The adsorption of phenol and m-cresol mixtures from aqueous solutions onto a macroporous polymeric adsorbent, Duolite ES-861, was investigated experimentally in a fixed-bed adsorber for different flowrates, feed concentrations and bed initial conditions (clean or pre-saturated).The experimental results are presented in this work, where the major objective is placed on the modelling of these fixed bed adsorption experiments using an extended Langmuir isotherm equation for two components, based on single component equilibrium data obtained for phenol and m-cresol.The model presented in this paper takes into account axial dispersion of the liquid phase, film diffusion and intraparticle mass transfer and successfully simulates the adsorption behaviour of the phenol and m-cresol mixtures.     

氧化锆填料的高效液相色谱性能评价

研究了采用溶胶－凝胶技术制备的４－６μｍ粒径氧化锆微球的晶体结构,比表面积,孔容,孔径分布及表面酸碱性,测得氧化锆以单斜相和四方相２种相存在。微球的比表面积为２１ｍ６２／ｇ;总孔容为０．１２８０ｃｍ＾３／Ｌ;平均孔直径为８．６ｎｍ。氧化锆的表面存在酸碱两性。分别以异丙醇／环己烷,二氧甲烷／环己烷及三氯甲烷／环己烷为流动相研究了苯酚衍生物,芳香烃衍生物及苯胺等碱性化合物的保留行为。     

纤维素-三(3,5-二甲基苯基氨基甲酸酯)涂敷氧化锆手性固定相的制备和色谱评价

制备并表征了涂敷纤维素-三(3，5-二甲基苯基氨基甲酸醋)-ZrO2手性固定相。以正己烷／异丙醇为流动相，研究了正相色谱条件下手性固定相对几类光学异构体的手性拆分能力。实验结果表明：氧化锆载体表面的碱性性质对光学对映体的手性拆分有很大影响；在常用流动相条件下，酸性对映体被完全滞留；纤维素-三(3，5-二甲基苯基氨基甲酸醋)-ZrO2手性固定相对于中性及碱性对映异构体的分离呈现出较好的手性拆分能力。     

新型阳离子凝胶吸附剂对活性橙的吸附研究

采用分步聚合的方法,以醛、酮、胺为原料通过溶液缩聚制备了新型阳离子凝胶吸附剂,通过吸附实验研究了阳离子凝胶对活性橙K-GN模拟染料废水的吸附效果并对其吸附行为和机理进行探讨。实验结果表明阳离子凝胶对活性橙的吸附以静电引力和基团间相互作用为主,热力学参数显示该吸附是一个自发、吸热和熵增过程,吸附行为可用准二级动力学方程描述,吸附等温线符合Langmuir和Freundlich等温吸附模型,30℃时凝胶对活性橙的饱和吸附量可达709 mg/g。     

一种新型甘油三酯吸附剂的制备及其对血清中甘油三酯的吸附性能研究

合成了一种新型的甘油三酯吸附剂-磺化羟乙基化交联壳聚糖，用其对血浆中甘油三酯进行吸附．实验结果表明，该吸附剂最高可使血清中的甘油三酯降低76．9％（每克树脂吸附量为6．25mg），而对血清中总蛋白（TP）的吸附较少．     

亲和吸附剂对细菌内毒素吸附性能的研究

制备了以球形纤维素为载体、8种氨基酸和1种聚赖氨酸为配基的吸附剂,对质量浓度为100.0pg/mL的内毒素水溶液进行了吸附研究,绘制了吸附等温线,并初步探讨了吸附机理.结果表明,精氨酸和赖氨酸配基具有良好的吸附能力,在1.5mL100.0pg/mL内毒素溶液中吸附量分别达到182.0和160.0pg/mL;吸附等温线显示,以赖氨酸为配基的吸附剂其吸附量随溶液内毒素浓度增加而线性增加,符合Langmuir吸附方程,吸附能力强,具有一定的临床应用前景.     

单宁酸与苯酚在复合功能树脂上的竞争吸附研究

研究了水源水和生化尾水中的代表性模拟背景污染物单宁酸和代表性有机毒物苯酚之间的竞争吸附行为,开展了单组分、同时竞争吸附和预负载竞争吸附实验.研究表明,单宁酸对苯酚在复合功能树脂上的吸附有显著削弱作用.竞争吸附机理包括孔堵塞和吸附质间作用:单宁酸对树脂上微孔的堵塞,减少了苯酚优势吸附位点的数量,降低了吸附剂表面的异质性;吸附质间作用削弱了树脂对苯酚的吸附作用力.     

Experimental Results and Analysis for Adsorption Ice-Making System with Consolidated Adsorbent

An adsorption ice-making machine has been built with a single consolidated adsorber and activated carbon-methanol pair. A consolidated adsorbent block made of activated carbon mixed with a binder with good heat transfer properties has been developed and implemented in the adsorber. The design is focused on the adsorber consisting of copper finned tubes and carbon blocks. Experimental tests have been performed suitable for ice making. This paper describes the experimental results of such an ice-maker operating with an intermittent cycle and a cycle time of 35 minutes. The thermal conditions used to test the cycle are: 115°C heat source, 22°C heat sink, the evaporator temperature corresponding to the chilled ethylene glycol temperature is –7°C. At this evaporating pressure, the mass transfer resistance controls the adsorption process. Test results show that the COP reaches 0.07 whereas the SCP (specific cooling power) is 11 W kg^–1 activated carbon. A two-bed adsorptive prototype ice-making machine operating with a heat and mass recovery cycle has also been made for onboard adsorption refrigeration in fishing boats. Good performances have been achieved due to improved mass transfer and the new ice maker can produce 18–20 kg h^–1 of flake ice at mean temperature of –7°C.