D152树脂对铜(Ⅱ)的吸附性能

The sorption behavior and mechanism of D152 resin for Cu~(2+) is investigated.D152 resin has a good adsorptivity for Cu~(2+) in the HAc-NaAc medium at pH=4.73.The statically saturated sorption capacity is 309mg/g·(resin).Cu~(2+)adsorbed on D152 resin can be eluted quantitatively by using 0.1-2.0mol/L hydrochloric acid as an eluant.The apparent rate constant and activation energy are k_(298)=1.86×10~(-5) sec~(-1) and Ea=12.3kJ/mol.The sorption behavior of D152 resin for Cu~(2+) obeys the Freundlich isotherm.The sorption thermodynamic parameters of D152 resin for Cu~(2+)are enthalpy change ΔH=14.6 kJ/mol,free energy change ΔG=-0.72kJ/mol,entropy change ΔS=51.4J/(mol·K).respectively.     

Poly-L-Histidine Attached Poly(glycidyl methacrylate) Cryogels for Heavy Metal Removal

Poly-L-histidine immobilized poly(glycidyl methacrylate) (PGMA) cryogel discs were used for the removal of heavy metal ions [Pb(II), Cd(II), Zn(II) and Cu(II)] from aqueous solutions. In the first step, PGMA cryogel discs were synthesized using glycidyl methacrylate (GMA) as a basic monomer and methylene bisacrylamide (MBAAm) as a cross linker in order to introduce active epoxy groups through the polymeric backbone. Then, the metal chelating groups are incorporated to cryogel discs by immobilizing poly-L-histidine (mol wt ≥ 5000) having poly-imidazole ring. The swelling test, fourier transform infrared spectroscopy and scanning electron microscopy were performed to characterize both the PGMA and poly-L-histidine immobilized PGMA [P-His@PGMA] cryogel discs. The effects of the metal ion concentration and pH on the adsorption capacity were studied. These parameters were varied between 3.0–6.0 and 10–800 mg/L for pH and metal ion concentration, respectively. The maximum adsorption capacity of heavy metal ions of P-His@PGMA cryogel discs were 6.9 mg/g for Pb(II), 6.4 mg/g for Cd(II), 5.6 mg/g for Cu(II) and 4.3 mg/g for > Zn(II). Desorption of heavy metal ions was studied with 0.1 M HNO₃ solution. It was observed that cryogel discs could be recurrently used without important loss in the adsorption amount after five repetitive adsorption/desorption processes. Adsorption isotherms were fitted to Langmuir model and adsorption kinetics were suited to pseudo-second order model. Thermodynamic parameters (i.e. ΔH° ΔS°, ΔG°) were also calculated at different temperatures.     

基于原子转移自由基聚合制备新型螯合树脂及其吸附性能

以氯甲基化聚苯乙烯树脂(CMPS)为基质, 通过表面引发原子转移自由基聚合(SI-ATRP)反应将聚甲基丙烯酸缩水甘油酯(PGMA)接枝到树脂表面, 再与亚氨基二乙酸(IDA)反应, 制备了一种新型螯合树脂. 采用红外光谱、 元素分析及比表面积与微孔分析仪对其结构进行表征. 树脂表面甲基丙烯酸缩水甘油酯(GMA)接枝量和IDA含量及对Ni(Ⅱ), Cu(Ⅱ)和Pb(Ⅱ)的吸附容量均随聚合时间的延长而增大, 聚合时间为18 h时, 最大吸附容量分别为1.29, 1.19和0.83 mmol/g. 结果表明, SI-ATRP是制备高吸附容量及吸附容量可控的螯合树脂的可行方法.     

高容量亚胺基二乙酸型螯合树脂的制备及吸附性能

以甲基丙烯酸缩水甘油酯(GMA)为单体, 氯甲基化的交联聚苯乙烯树脂(CMCPS)为大分子引发剂, CuBr/2,2'-联吡啶(Bpy)为催化剂, 采用表面引发原子转移自由基聚合(SI-ATRP)技术, 使甲基丙烯酸缩水甘油酯聚合在CMCPS树脂表面, 制得了环氧化聚合物. 将该聚合物与亚胺基二乙酸(IDA)反应, 制备了高容量亚胺基二乙酸型螯合树脂(IDA-PGMA-CMCPS), 用元素分析对其进行了表征. 考察了螯合树脂对Cu²⁺的吸附性能及动力学和热力学参数. 该螯合树脂表面IDA接枝密度达8.15 mg/m². 研究结果表明, 树脂对Cu²⁺的吸附量随离子浓度和温度的升高而增加, 当pH值为2.2时, 对Cu²⁺离子的吸附效果最佳. 树脂的静态饱和吸附容量为1339.66 mg/g, Langmuir和Freundlich方程均呈现良好的拟合度. 通过热力学平衡方程计算ΔG<0, ΔH=270.60 kJ/mol, ΔS>0, 表明该吸附过程是自发、 吸热、 熵增加的过程. 动力学研究结果表明, 准二级动力学方程能较好拟合动力学实验结果, 该过程符合准二级动力学模型.     

Immunoadsorption of cholesterol on protein A oriented beads

Anti-low density lipoprotein antibody (anti-LDL) molecules were attached covalently and oriented through Protein A onto poly(2-hydroxyethyl methacrylate-ethylene glycol dimethacrylate) [poly(HEMA-EGDMA)] beads in order to remove cholesterol specifically from hypercholesterolemic human plasma. Poly(HEMA-EGDMA) beads were produced by suspension polymerization. Blood compatibility tests were performed. All the clotting times were increased when compared with control plasma. Loss of platelets and leukocytes was very low. The maximum anti-LDL attachment was 11.6 mg . g(-1) in the case of random immobilization and 28.3 mg . g(-1) in the case of oriented immobilization. In the latter case, Protein A loading was 8.3 mg . g(-1) at pH 7.5 (borate buffer, 0.15 M NaCl). There was low non-specific cholesterol adsorption onto the poly(HEMA-EGDMA) beads, about 0.83 mg . g(-1). Random and oriented anti-LDL attached beads adsorbed 8.2 mg and 11.7 mg cholesterol per g of bead from hypercholesterolemic human plasma, respectively. Up to 96% of the adsorbed cholesterol was desorbed. The binding-elution cycle was repeated 6 times using the same beads. There was no significant loss of binding capacity.     

原子转移自由基聚合法用于以单分散树脂为基质的强阳离子交换色谱固定相的制备及其色谱性能研究

以7μm单分散交联聚甲基丙烯酸环氧丙酯树脂表面键合溴异丁酰溴为引发剂,以CuCl/CuCl2/2,2-联二吡啶(Bpy)为催化体系,采用封闭体系,在氮气保护下,以乙烯基苯磺酸钠(NaSS)为单体、N,N-二甲基甲酰胺(DMF)水溶液为溶剂,制备了强阳离子交换色谱(SCX)固定相,并用元素分析与红外光谱法对其进行了表征....     

高亲水性强阳离子交换色谱填料的制备及其在蛋白质分析中的应用

以具有双孔结构的聚甲基丙烯酸环氧丙酯(PGMA)微球为基质,以葡萄糖进行表面亲水改性,制备了强阳离子交换色谱填料,并将其用于复杂生命体系中生物大分子的快速而高效的分离、分析与纯化。葡萄糖亲水改性增进了填料的生物相容性,提高了蛋白质样品的回收率;双孔结构及较高的比表面积赋予填料良好的柱渗透性和样品负载量。以标准蛋白质为样品,考察了该填料对生物样品的分离性能。以100 mm×4.6 mm的色谱柱分离4种蛋白质,在6 min内实现了基线分离;以溶菌酶为样品,填料的吸附容量为39.5 g/L,在蛋白质快速分离纯化分析中显示了良好的应用前景。     

PREPARATION OF CHITOSAN COATED METAL AFFINITY CHROMATOGRAPHY ADSORBENT

A new and an inexpensive adsorbent of chitosan coated silica for immobilized metal affinity chromatography(IMAC) was studied.After a double coating,the chitosan coated on silica beads could be up to 53.4mg/g silica beads.When pH&gt;3.8,the metal ligand Cu^2+ was chelated on the coated chitosan with a bound capacity of 14.6mg/g chitosan without introducing iminodiacetic acid(IDA).     

Three novel high performance affinity chromatographic media for the separation of antithrombin III from human plasma.

Novel monodisperse, non-porous, cross-linked poly (glycidyl methacrylate) beads (PGMA) were employed as the support for high performance affinity chromatography. Heparin was covalently attached to PGMA beads by three different coupling methods. Heparin-PGMA-I was prepared by directly coupling amino-groups of heparin with PGMA. Heparin-PGMA-II and III were prepared by the coupling of heparin to amino-PGMA, which was obtained by amination of PGMA. Heparin-PGMA-II was prepared by coupling the carboxyl groups of heparin to amino-PGMA by using water-soluble carbodiimide as coupling reagent, and heparin-PGMA-III was prepared by the reductive amination of heparin and amino-PGMA with sodium cyanoborohydride. The heparin contents of heparin-PGMA-I, II and III were 1.6, 10.2 and 1.0 mg/g beads, respectively. Their affinity capacities for antithrombin III were investigated. Their binding activity to antithrombin III was not proportional to the content of heparin immobilized, and heparin-PGMA-I was the most efficient affinity medium for antithrombin III. The resultant affinity media presented minimal non-specific interaction with other proteins and can be used in a wide pH range. All the three heparin-PGMA beads were exploited for the separation of antithrombin III from human plasma. The purity of antithrombin III obtained was higher than 90%, which was confirmed by high performance size exclusion chromatography.     

桑色素修饰的纳米TiO_2分离富集铬和铝

建立了在表面活性剂十二烷基硫酸钠(SLS)的活化作用下,桑色素修饰的纳米TiO2分离富集,电感耦合等离子体原子发射光谱(ICP-AES)测定Cr3+和A l3+的新方法。考察了溶液pH、洗脱条件和干扰离子等因素对分析物分离富集的影响。结果表明,在pH 3.0时,Cr3+和A l3+可被桑色素修饰的纳米TiO2定量富集,吸附的金属离子可用1.5 mL 0.50 mol/L HC l溶液完全洗脱。在优化的实验条件下,纳米TiO2-桑色素对Cr3+和A l3+的吸附容量分别为9.69 mg/g和12.76 mg/g。本法对Cr3+和A l3+的检出限(3σ)分别为:0.21和0.49 ng/mL,相对标准偏差(RSD)分别为2.2%和1.6%(n=11,C=50 ng/mL)。本法应用于藏药和扇贝标准样品(GBW 10024)中Cr3+和A l3+的测定,测定值与标准值基本吻合,分析结果满意。     

水杨酸型螯合吸附材料对重金属离子的吸附性能

将5-氨基水杨酸接枝到PGMA/SiO2微粒的聚甲基丙烯酸缩水甘油酯(PGMA)大分子链上,成功制备了一种新型螯合吸附材料ASA-PGMA/SiO2。采用静态法研究了ASA-PGMA/SiO2对重金属离子Cu2+、Cd2+、Zn2+、Pb2+的吸附性能,结果表明其对Cu2+、Cd2+、Zn2+、Pb2+具有很强的螯合吸附能力,吸附容量分别可以达到0.42、0.40、0.35、0.31mmol/g。体系的pH对吸附容量影响较大,吸附行为服从Langmuir和Freundlich吸附模型。使用0.1mol/L的盐酸溶液就可实现重金属离子的解吸。通过反复吸附-解吸实验证明ASA-PGMA/SiO2具有良好的重复使用性能。     

Surface grafting of glycidyl methacrylate on silica gel and polyethylene beads

Surface grafting of glycidyl methacrylate (GMA) on silica gel and a polyethylene bead was performed by radical polymerization and radiation-induced polymerization, respectively, in order to improve softness. Subsequently, diethylene triamine (DETA), triethylene tetraamine (TETA), and iminodiacetic acid (IDA) were introduced to the grafted GMA for use as affinity columns. The efficiency of the affinity column was investigated by use of bovine serum albumin (BSA) and hemoglobin (Hb) as model proteins. The affinity degree of BSA was higher than Hb for the DETA and TETA column, whereas the affinity degree of Hb was higher than BSA for the IDA column supported by silica gel. The affinity degree of BSA was higher than Hb for the DETA and TTA column supported by polyethylene (PE) beads.     

Optimization of polyacrylonitrile-cysteine resin synthesis and its selective removal of Cu(Ⅱ) in aqueous solutions

Polyacrylonitrile beads(PAN) cysteine(CS) was synthesized from polyacrylonitrile beads(PAN) and cysteine(CS).The content of the functional group and the percentage conversion of the functional group of PAN-CS prepared under the optimum condition using response surface methodology(RSM) for the first attempt were 3.22 mmol/g and 35.78%.The structure was characterized by ET-IR and elemental analysis.The adsorption properties of the resin for Cu(Ⅱ) were investigated by batch and column experiments.Batch adsorption results suggested that PAN-CS had higher adsorption capability for Cu(Ⅱ)than other metal ions and maximum saturated adsorption capacity was 184.7 mg/g.The resin and its metal complexes were studied by FT-IR.Furthermore,the resin can be eluted easily using 1 mol/L HC1.PAN-CS can provide a potential application for selective removal of copper from waste solution.     

Purification of transferrin by magnetic immunoaffinity beads

Immunoaffinity adsorbent for transferrin (Tf) purification was prepared by immobilizing anti‐transferrin (Anti‐Tf) antibody on magnetic monosizepoly(glycidyl methacrylate) beads, which were synthesized by dispersion polymerization technique in the presence of Fe₃O₄nanopowder and obtained with an average size of 2.0 μm. The magnetic poly(glycidyl methacrylate) (mPGMA) beads were characterized by Fourier transform infrared spectroscopy, swelling tests, scanning electron microscopy, electron spin resonance spectroscopy, thermogravimetric analysis and zeta sizing analysis. The density and swelling ratio of the beads were 1.08 g/cm³ and 52%, respectively. Anti‐Tf molecules were covalently coupled through epoxy groups of mPGMA. Optimum binding of anti‐Tf was 2.0 mg/g. Optimum Tf binding from aqueous Tf solutions was determined as 1.65 mg/g at pH 6.0 and initial Tf concentration of 1.0 mg/mL. There was no remarkable loss in the Tf adsorption capacity of immunoaffinity beads after five adsorption–desorption cycles. Tf adsorption from artificial plasma was also investigated and the purity of the Tf molecules was shown with gel electrophoresis studies.     

Immobilization of ß-Galactosidase on Benzoquinone-Activated Bead-Cellulose1

ß-galactosidase from Escherichia coli was immobilized on porous bead cellulose by a benzoquinone coupling method. Optimum conditions for activation and coupling were investigated, and the kinetic parameters of the immobilized enzyme described. The binding capacity was 15.6mg/g of wet conjugate, corresponding to 109 mg/g dry matrix. A saturation activity of 4100 U/g dry cellulose beads was achieved. The apparent Michaelis constant of the immobilized ß-galactosidase at pH 7.6 for orthonitrophenylgalactopyranoside was 2.4 x 10-3 mol/liter, as compared to 2.4 x 10-4 mol/liter of the native enzyme. The stability of benzoquinone-activated bead cellulose and of immobilized ß galactosidase were also determined.     

金属离子与氨羧类螯合配体的键合特性研究

利用前沿色谱法,通过Cu2+、Ni2+和Co2+与螯合配体IDA 键合的准确度(R2>0.98)与精密度(RSD <5%)实验,研究了前沿色谱法同时测定络合稳定常数KML与总键合位点数Λ0值的可行性.为了进一步证明前沿色谱法的普适性,以Cu2+、Ni2+和Co2+为代表,在3种键合缓冲体系(NaAc-HAc、Na-PB、Tris-HCl)中,考察了金属离子在3种氨羧类螯合配体(IDA、Asp、Glu)上络合稳定常数KML的变化规律.结果表明,螯合配体对金属离子键合强度遵循IDA>Asp>Glu;金属离子对螯合配体键合强度遵循Cu2+>Ni2+>Co2+;3种键合缓冲体系中,NaAc-HAc键合效果最好.按照M06/6-311++G (d, p) 方法对螯合配体与金属离子的结合能(ΔE)与吉布斯自由能(ΔG)进行相关的量子计算.根据ΔE 与ΔG 的大小,从理论上推测出螯合配体与金属离子的键合规律,此规律与上述实验结果基本相符.本研究为金属离子与螯合配体间键合参数的求取提供了有效的方法和手段,从而为今后提高IMAC柱的稳定性,解决固定金属亲和柱在应用过程中尤其是竞争洗脱过程中金属离子的流失问题奠定了良好的基础.     

717型阴离子交换树脂吸附水溶性芳香族有机污染物研究

研究了717型阴离子交换树脂对苯酚、苯甲酸和十二烷基苯磺酸钠(SDBS)等水溶性芳香族污染物吸附过程的基本化学问题.研究结果表明:717型树脂对苯酚、苯甲酸和SDBS的吸附过程均符合Lagergren二级吸附动力学方程,吸附速率均随着温度的升高而加快,吸附表观活化能Ea分别为13.2kJ/mol、59.5kJ/mol和48.1kJ/mol,吸附过程△H0和△S0均为正值,△G0均为负值,吸附能够自发进行;吸附等温模型符合Langmuir等温式;318K时,717型树脂在pH=9.1对SDBS的饱和吸附容量为360mg/g;在pH=10.2,对苯酚和苯甲酸的饱和吸附容量分别为194mg/g和286mg/g.用浓度均为0.5mol/L,体积比为5∶1的NaCl-NaOH混合溶液可快速洗脱树脂上吸附的污染物,洗脱率达98％以上.该树脂对水溶性芳香族污染物吸附容量大,易于再生和循环利用,可用于环境水体中水溶性芳香族有机污染物的吸附治理.     

粉煤灰合成Na-X沸石去除废水中镍离子的研究

粉煤灰通过碱熔融 水热法合成了Na-X型沸石,研究了Na-X型沸石的用量、吸附时间、溶液pH值、初始镍离子浓度和温度对废水中镍离子去除效果的影响。结果表明,Na-X型粉煤灰沸石对镍离子的去除性能与化学原料合成的13X相当,明显优于粉煤灰。在20℃,pH值为6,沸石用量10g/L,吸附15min时,对初始浓度为20mg/L~150mg/L的镍离子去除率均可达90%以上。镍离子的吸附过程符合Langmiur吸附等温方程式,其单层吸附量为11.2×10^-3。粉煤灰沸石重复使用5次,对废水中镍离子的去除率仍高达95%,再生性能良好。     

Heavy Metal Removal from Synthetic Solutions with Magnetic Beads Under Magnetic Field

The aim of this study is to prepare magnetic beads which can be used for the removal of heavy metal ions from synthetic solutions. Magnetic poly(ethylene glycol dimethacrylate‐vinyl imidazole) [m‐poly(EGDMA‐VIM)] beads were produced by suspension polymerization in the presence of magnetite Fe₃O₄ nano‐powder. The specific surface area of the m‐poly(EGDMA‐VIM) beads was found to be 63.1 m²/g with a size range of 150–200 µm in diameter and the swelling ratio was 85%. The average Fe₃O₄ content of the resulting m‐poly(EGDMA‐VIM) beads was 12.4%. The maximum binding capacities of the m‐poly(EGDMA‐VIM) beads were 32.4 mg/g for Cu²⁺, 45.8 mg/g for Zn²⁺, 84.2 mg/g for Cd²⁺and 134.5 mg/g for Pb²⁺. The affinity order on mass basis is Pb²⁺>Cd²⁺>Zn²⁺>Cu²⁺. Equilibrium data agreed well with the Langmuir model. pH significantly affected the binding capacity of the magnetic beads. Binding of heavy metal ions from synthetic wastewater was also studied. The binding capacities were 26.2 mg/g for Cu²⁺, 33.7 mg/g for Zn²⁺, 54.7 mg/g for Cd²⁺ and 108.4 mg/g for Pb²⁺. The magnetic beads could be regenerated up to about 97% by treating with 0.1 M HNO₃. These features make m‐poly(EGDMA‐VIM) beads a potential candidate for support of heavy metal removal under magnetic field.     

Site‐specific reversible immobilization and purification of His‐tagged protein on poly(2‐acetamidoacrylic acid) hydrogel beads

Ni²⁺‐complexed poly(2‐acetamidoacrylic acid) (PAAA) hydrogel beads were developed for the site‐specific reversible immobilization and purification of the histidine‐tagged green fluorescent protein (His‐tagged GFP). PAAA hydrogel beads were prepared by photopolymerization, and significantly improved mechanical properties of PAAA hydrogel beads were observed in comparison with PAAA hydrogel from our previous study. Confocal laser scanning microscopy was used to determine the binding of His‐tagged GFP to the hydrogel beads in three‐dimensional space. Photoluminescence spectroscopy revealed 89% of binding efficiency of His‐tagged GFP to the Ni²⁺‐PAAA hydrogel beads, 51% of yielding recovery. The maximum binding capacity of His‐tagged GFP was estimated to be 0.45 µg/mg of Ni²⁺‐PAAA hydrogel beads. The recombinant His‐tagged GFP from the soluble fraction of E. coli BL21(DE3) cell lysates was purified with Ni²⁺‐PAAA hydrogel beads. The major advantage of the Ni²⁺‐PAAA hydrogel beads system was simple preparation procedures of producing the matrix, because PAAA hydrogel beads had relatively enhanced mechanical strength than soft hydrogels. Copyright © 2012 John Wiley & Sons, Ltd.