凝胶色谱与多角激光光散射联用研究聚氧化乙烯的扩展效应和链构象

采用凝胶色谱与多角激光光散射联用的方法,测定了一系列不同分子量的聚乙二醇(PEG)和聚氧化乙烯(PEO)在色谱柱中的扩展效应.扩展因子随PEG/PEO分子量的增加而增大,经扩展效应改正后得到了样品的准确分子量和分子量分布.同时建立了PEO的Z均回转半径Rgz与重均分子量Mw之间的单分散标度关系:Rgz=0.0272 Mw0.56,结果表明,长链PEO在水溶液中由于排除体积效应采取溶胀的无规线团构象.     

凝胶排阻色谱法测定中空纤维超滤膜组件对聚乙二醇的截留率

采用凝胶排阻色谱法测定中空纤维超滤膜组件对聚乙二醇20000(PEG20000)溶液的截留率,选择Agilent PL aquagel-OH MIEXD–H8μm色谱柱,流动相为0.1 mol/L Na NO3溶液(含0.02%Na N3),流量为1 m L/min,RID检测器,柱温箱和检测器温度均为30℃。当进样体积为50μL时,方法的检出限为18.8 mg/L,定量限为49.0 mg/L。PEG20000溶液的质量浓度在60~1 000 mg/L范围内与色谱峰高呈良好的线性,相关系数r2=1.000。该方法对实际样品测定结果的相对标准差为1.31%(n=6)。将该方法的测定结果与紫外–可见分光光度计法的测量结果进行F检验和t检验,结果表明两种方法测量结果无显著性差异。采用该方法可以同时对PEG20000样品的相对分子质量及其分布进行测定,从而对选用的截留标准物质进行质量控制。     

超高效合相色谱法同时测定复合维生素片中11种脂溶性维生素及其衍生物

建立了超高效合相色谱法(Ultra performance convergence chromatography,UPC2)分离和测定复合维生素片中11种脂溶性维生素(A,D,E,K)及其衍生物的方法。超高效合相色谱(UPC2)技术集合超临界流体色谱(Supercritical fluid chromatography,SFC)和超高效液相色谱(Ultra performance liquid chromatography,UPLCTM)的技术优点,流动相以CO2为主体,乙腈为助溶剂梯度洗脱。选用Waters Acquity UPC2HSS C18SB色谱柱(100 mm×3.0 mm 1.8μm),流速1 m L/min,检测波长为284 nm。方法检出限在1.5~2.0 mg/L之间;VK1,VK2,VK3和VD3的线性范围分别为3~300 mg/L;VA、VA棕榈酸酯、VA甲酸、VE、VE醋酸酯、VE琥珀酸酯和VD2的线性范围分别为5~300 mg/L;加标回收率范围为97.31%~98.76%;相对标准偏差为0.41%~0.96%,可以满足复合维生素片中11种脂溶性维生素(A,D,E,K)及其衍生物的方法要求。     

合成条件对硅胶整体柱中孔结构的影响

硅胶整体柱是目前备受关注的液相色谱固定相。本文考察了合成条件对硅胶整体柱中孔结构的影响,包括反应体系的pH值、聚乙二醇(PEG)含量及分子量。实验表明,反应体系的pH值能有效地调控硅胶整体柱的中孔孔径及孔结构,当pH值为2或5时,整体柱中孔孔径较小;而当pH值为3或9时,孔径较大,孔结构趋于圆筒状。整体柱的中孔平均孔径随着PEG含量和分子量的增加而增加,其孔径分布也逐渐变宽。     

水溶性凝胶渗透色谱法测定碱木素分子量

应用水溶性凝胶渗透色谱法测定了碱木素的分子量,与脂溶性凝胶渗透色谱法的测定结果基本一致。色谱柱为Ｕｌｔｒａｈｙｄｒｏｇｅｌ凝胶色谱柱,流动相为氢氧化钠溶液（ｐＨ１２）。系统考察了不同流动相对碱木素在凝胶柱上吸附的影响,结果发现,增大流动相离子强度有利于减少碱木素的吸附,但流动相的酸度对于碱木素吸附具有更重要的影响,ｐＨ值高时,碱木素吸附减弱。实验同时表明,高分子量的碱木素更易在凝胶柱上发生吸附。     

聚苯乙烯凝胶色谱柱分离头孢呋辛钠聚合物杂质

建立了聚苯乙烯基质的凝胶色谱柱系统对头孢呋辛钠中聚合物杂质(或称缩合物杂质)的分离分析方法.凝胶色谱柱为MKF-GPC-100柱(100 mm×7.8 mm,5 μm),流动相为0.01 mol/L的磷酸盐缓冲液(pH 7.0)-乙腈(70:30,体积比),流速1.0 mL/min,检测波长254 nm.头孢呋辛钠与其...     

高效凝胶排阻色谱法测定牛血清白蛋白相对分子质量及其分布

建立了一种高效凝胶排阻色谱快速测定牛血清白蛋白的相对分子质量及其分布的方法。使用凝胶色谱仪,TSKgel G3000SWXL型(300 mm×7.8 mm)高效凝胶排阻色谱柱,以0.05 mol/L磷酸盐缓冲溶液(pH 6.8)–0.3mol/L氯化钠溶液为流动相,流速为1 mL/min,DAD检测器,检测波长为220 nm,选择300~330 nm作为参比波长,信号采集时间为15 min。测得质控样牛血清白蛋白相对分子质量标准物质峰值相对分子质量的均值为7.160×104Da,与参考值的相对误差为7.76%,组间相对标准偏差为0.49%。采用该法对市售牛血清白蛋白样品的相对分子质量分布进行测试,组内相对标准偏差为0.004%~0.014%,组间相对标准偏差为1.89%。该法可以满足一般实验室对牛血清白蛋白样品的分子量分布测定的要求。     

定量体积排除色谱测定高分子双水相系统的组成和分子量分布

利用定量体积排除色谱研究葡聚糖-聚乙二醇双水相系统相分离后上下两相中2种高分子组分的含量、分子量和分子量分布.由定量体积排除色谱法得到的两相组成(即系线端点)与用浊点滴定法得到的浊点曲线几乎完全重合,二者仅在靠近临界点的聚乙二醇富集相有一定偏差.同时,利用体积排除色谱测得两相中葡聚糖和聚乙二醇的分子量和分子量分布.结果表明,由系线端点得到的体系两相共存线与浊点曲线的偏差是由于相分离过程中,不同分子量的高分子组分在两相的非均匀分配造成的.聚乙二醇分子量分布较窄,发生相分离后,在两相的分子量和分子量分布相差不大.而葡聚糖分子量分布较宽,在相分离后两相中的分子量和分子量分布具有较大差异,即葡聚糖组分在葡聚糖富集相中的分子量显著高于其在聚乙二醇富集相中的分子量.随着葡聚糖-聚乙二醇体系初始浓度的增加,两相中葡聚糖的分子量差异变大.定量体积排除色谱可以准确得到高分子双水相系统的相平衡数据及两相中2组分的分子量和分子量分布信息,其结果不仅为深入理解葡聚糖-聚乙二醇-水三元溶液的相平衡提供基础,而且为双水相系统在萃取分离中的应用提供理论指导.     

凝胶渗透净化–超高效液相色谱–串联质谱法测定橙汁中链格孢霉毒素

建立橙汁中4种链格孢霉毒素含量测定的凝胶渗透–超高效液相色谱–串联质谱检测方法。样品用乙腈提取后,用填料为Bio-Beads-S–X3的凝胶渗透色谱柱净化,净化时流动相采用乙酸乙酯–环己烷(体积比为1∶1),流速为5 mL/min,测定时用超高效液相反相C18色谱柱分离,甲醇–水系统梯度洗脱,采用电喷雾负离子源和多反应监测(MRM)模式定性和定量。4种链格孢霉毒素的最低定量限在0.0004～0.002 mg/kg范围内,加标回收率为78.9%～111.5%,测定结果的相对标准偏差均低于9.0%(n=10)。     

单一分布聚乙二醇的合成及其应用

聚乙二醇(PEG)经过对端基官能团化接枝到药物等生物活性分子上后,可提高药物等的水溶性、抗免疫原性、生物相容性和稳定性并降低毒性。工业级聚乙二醇由于杂质含量高尤其是其中二醇的含量过高、分子量分布过宽,不能直接用于药物等的改性。除利用聚合方法制备窄分布高纯度的聚乙二醇外,采用有机合成方法合成单一聚乙二醇链是有效的手段。对"单一链长(discrete length)"或者"单一分布(mono-disperse)"的聚乙二醇高分子聚合物的近年来主要合成方法的进展进行了综述并简介了其主要应用。     

Polysulfone Membranes via Thermally Induced Phase Separation

Polysulfone (PSF) membranes have gained great attention in the fields of ultrafiltration,microfiltration,and thin film composite membranes for nanofiltration or reverse osmosis.For the first time,it is proposed to fabricate PSF membranes via thermally induced phase separation (TIPS) process using diphenyl sulfone (DPSO2) and polyethylene glycol (PEG) as mixed diluent.DPSO2 is chosen as a crystallizable diluent,while PEG is considered in terms of molecular weight (Mw) and dosage.We systematically investigate the interactions between PSF,DPSO2 and PEG based on the simulation calculations and solubility parameter theory.It is inferred that DPSO2 has an excellent compatibility with PSF,and the addition of PEG results in the ternary system thermodynamically less stable and then facilitates its liquid-liquid (L-L) phase separation.SEM images indicate that cellular-like pores are obvious throughout the membrane when the PEG content in the mixed diluent is 25 wt％-35 wt％.We can facilely manipulate the pore size,water flux and mechanical properties of PSF membranes with the dosage of PEG-200,the Mw of PEG or the cooling rate.The successful application of TIPS can provide a new approach for structure manipulation and performance enhancement of PSF membranes.     

不同分子量PEG的铜电镀液对电化学沉积铜行为的研究

研究了在酸性镀铜溶液中添加不同分子量的PEG对直径为50微米、深径比为1的镀层盲孔填充效果的影响.结果表明,随着PEG分子量的增加,电镀铜溶液的微孔填充力明显提高.电流密度为2 A/dm2,添加剂PEG分子量(u)超过6000时,镀液可以完全填充盲孔,镀层不出现任何空洞和缝隙.这是由于添加剂PEG能明显加强电镀铜镀液阴极极化,抑制了电镀铜的沉积.同时,PEG于镀液中的扩散系数还随其分子量的增加而降低,从而增加了SPS在微孔底部的吸附力,加速了电镀铜在微孔底部的沉积.进一步,增大PEG分子量,沉积铜膜的表面粗糙度、铜膜结晶度和电阻率均有所降低.     

Surface and Thermodynamic Properties of Nonionic Surfactants Based on Rosin-Maleic Anhydride and Acrylic Acid Adducts

Ester-adduct derivatives of rosin were synthesized by reacting rosin maleic anhydride (RMA) or rosin acrylic acid (RAA) adducts with polyethylene glycol 600 (PEG600), 1000 (PEG1000) or 2000 (PEG2000) and at elevated temperature. These derivatives were evaluated for acid number, FTIR spectroscopy, molecular weight (Mw) and polydispersity. The surface properties of the prepared surfactants were determined by measuring the surface tension at different temperatures. The surface tension, critical micelle concentration, and surface activities were determined at different temperatures. Surface parameters such as surface excess concentration (Γmax), the area per molecule at interface (Amin) and the effectiveness of surface tension reduction (πCMC) were determined from the adsorption isotherms of the prepared surfactants. Some thermodynamic data for the adsorption process were calculated and are discussed.     

Synthesis and Properties of Nonionic Surfactants from Rosin-Imides Maleic Anhydride Adduct

Ester-adduct derivatives of rosin were synthesized by reacting rosin with polyethylene glycol 600 (PEG 600) or 2000 (PEG2000) and maleic anhydride (MA) at elevated temperature. These derivatives were evaluated for acid number, FTIR spectroscopy, molecular weight (Mw), and polydispersity. The derivatives were soluble in organic solvents; aqueous solubility was pH dependent. Rosin-imides were synthesized from a rosin ester-maleic anhydride adducts. It was condensed with diaminobutane or triethylene tetramine to obtain rosinimides. This imide was etherified by reaction with PEG in the presence of β,β′-dichlorodiethyl ether as a linking agent and NaOH as a catalyst. The surface properties of the prepared surfactants were determined by measuring the surface tension at different temperatures. The surface tension, critical micelle concentration and surface activities were determined at different temperatures. Surface parameters such as surface excess concentration (Γmax), the area per molecule at interface (Amin), and the effectiveness of surface tension reduction (πCMC) were determined from the adsorption isotherms of the prepared surfactants. Some thermodynamic data for the adsorption process were calculated and are discussed.     

聚乙二醇分子量对成纤共聚酯结晶速度的影响

<正> 以聚对苯二甲酸乙二酯(PET)为主体添加聚乙二醇(PEG)的共聚物以及以聚对苯二甲酸乙二酯为主体添加含有磺酸盐基团的共聚组分和聚乙二醇的共聚物是两类重要的成纤共聚醚酯,前者(简称为PEE-1)制成的纤维可用分散染料常压沸染,后者(简称为PEE-2)制成的纤维则可用阳离子染料进行染色。     

Surface affinity chromatographic separation of blood cells. III. Effect of molecular weight of polyethylene glycol bonded stationary phases on elution behaviour of human blood cells

The chromatographic behaviour of human peripheral blood cells on four kinds of oxirane-coupled polyethylene glycol (PEG)--Sepharose 6B columns was investigated by using an eluent containing 2% of dextran T40. The retention volumes of lymphocytes, granulocytes and platelets at pH 7.5 have a strong dependence on the average molecular weight of the bonded PEG in the range 400-20,000, increasing with increasing molecular weight. Further, the same tendency for the retention behaviour was also observed at the isoelectric points determined for the four kinds of blood cells by using the cross-partition method. For lymphocytes and granulocytes hydrophobic interactions with the bonded PEG phase were found to be predominant, whereas for erythrocytes and platelets electrostatic interactions were also taken into account.     

Fabrication study of polysulfone hollow-fiber microfiltration membranes: Optimal dope viscosity for nucleation and growth

Fabrication of polysulfone hollow-fiber microfiltration membranes through non-solvent induced phase separation (NIPS) by dry–wet spinning was studied. For all sample preparations, we used N-methylpyrrolidone (NMP) as solvent, polyethylene glycol (PEG) as additive, aqueous NMP solution as bore liquid, and water as coagulation bath. Particular focus was placed on the influence of PEG molecular weight (Mw) on membrane structure. Characterization of the obtained membranes was performed by measuring pure water permeate flux, tensile strength, and tensile elongation at break, and by analyzing scanning electron microscope (SEM) images of hollow-fiber cross-sections, outer surfaces, and inner surfaces.     

Efficient Design to Monitor the Site-specific Sustained Release of a Non-Emissive Anticancer Drug

A pH-responsive smart nanocarrier with significant components was synthesized by conjugating the non-emissive anticancer drug methyl orange and polyethylene glycol derived folate moiety to the backbone of polynorbornene. Complete synthesis procedure and characterization methods of three monomers included in the work: norbornene-derived Chlorambucil (Monomer 1), norbornene grafted with polyethylene glycol, and folic acid (Monomer 2) and norbornene attached methyl orange (Monomer 3) connected to the norbornene backbone through ester linkage were clearly discussed. Finally, the random copolymer CHO PEG FOL METH was synthesized by ring-opening metathesis polymerization (ROMP) using Grubbs′ second-generation catalyst. Advanced polymer chromatography (APC) was used to find the final polymer‘s molecular weight and polydispersity index (PDI). Dynamic light scattering, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were utilized to explore the prodrug‘s size and morphology. Release experiments of the anticancer drug, Chlorambucil and the coloring agent, methyl orange, were performed at different pH and time. Cell viability assay was carried out for determining the rate of survived cells, followed by the treatment of our final polymer named CHO PEG FOL METH.     

Effect of Chain Length of Polyethylene Glycol and Crosslink Density (NCO/OH) on Properties of Castor Oil Based Polyurethane Elastomers

The equilibrium swelling study of polyurethanes (PU) was carried out in various solvents in order to calculate their solubility parameter. The kinetics of swelling and sorption have also been studied in 1,4‐dioxane at 30°C. The PU was synthesized by reacting a novel polyol (castor oil derivative and epoxy based resin, EpxR) and one of the polyethylene glycols (PEG 200, PEG 400, PEG 600) with different weight compositions, with a toluene diisocyanate (TDI) adduct (derived from toluene diisocyanate and R60 polyol). Different NCO/OH ratio viz. 1, 1.3 and 1.7 were employed in the study. The results were found to vary with the weight composition of polyol components, as well as the crosslink density of the samples. The sorption behavior is also found to vary with the molecular weight of polyethylene glycol employed in the preparations of the polyurethanes. Kinetic studies of swelling revealed that the sorption is anomalous in nature. The diffusion coefficient (D) increased with an increase in the NCO/OH ratio and decreased with an increase in chain length of polyethylene glycol. The sorption coefficient (S) decreased with an increase in crosslink density (NCO/OH) and increased with increasing polyethylene glycol (i.e., PEG 200, PEG 400, and PEG 600) moieties in the polyurethanes. The molecular weight between two crosslink points was calculated using the Flory Rehner equation (24), and hence, the number of chains per unit volume (N) and degree of crosslinking (ν) in all the samples were determined.