共查询到20条相似文献,搜索用时 250 毫秒
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用粒径约0.5微米季胺化单分散交联聚苯乙烯胶乳与粒径为5~30微米磺化交联聚苯乙烯共聚物微球藉库伦力附聚得到了阴离子交换树脂微球,并对磺化深度,基球和胶乳的粒径比以及交联度等对阴离子交换树脂附聚微球色谱性能的影响进行了分析。用这种阴离子交换树脂附聚微球作为HPIC分离柱的填料;用自制的全多孔强阳离子交换树脂YSG-SO_3H为抑制柱填料,仅用10厘米长的分离柱在约27分钟内即可使F~-、Cl~-、No_2~-、HPO_4~-、Br~-、No_3~-、及SO_4~-等阴离子混合样按顺序全分离。 相似文献
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以自制的5.0 μm单分散大孔亲水交联聚甲基丙烯酸环氧丙酯(PGMA/EDMA)微球为基质,对其表面进行化学改性,合成弱阳离子交换色谱填料(WCX)。详细考察了该填料对标准蛋白质的分离性能、表面亲水性能、稳定性和重现性以及流速对蛋白保留的影响。实验结果表明,该色谱填料对蛋白的分离性能、重现性及稳定性良好;在流速为3 mL/min时,采用线性梯度洗脱,6 min内可分离4种标准碱性蛋白质,以溶菌酶测定的该填料的动力学吸附容量为29.86 mg/g。将其用于鱼精蛋白的分离纯化,经反相高效液相色谱测定纯化后鱼精蛋白的纯度为99.2%;与商品Shodex IEC SP-825强阳离子交换色谱柱比较,纯化结果几乎一样。 相似文献
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以2.5 μm的单分散聚苯乙烯为种子,乙二醇二甲基丙烯酸酯 (EDMA)为交联剂,甲苯和环己醇为致孔剂,采用"一步种子溶胀聚合法"制备了单分散微球; 再以过硫酸钾为引发剂将水溶性温敏单体N-异丙基丙烯酰胺(NIPAM)分子引发聚合到微球表面,制备了粒径为7.0 μm、分散系数为0.02的单分散交联温敏色谱填料,温敏单体NIPAM的接枝率为5.2%.考察了该填料对标准蛋白质的分离性能、温敏性能、稳定性和重现性以及动态吸附容量对蛋白保留的影响.实验结果表明,该色谱填料对蛋白的分离性能、温敏性能、稳定性及重现性良好,且对溶菌酶的动态吸附容量为32.3 mg/g.在疏水模式下,该填料不但可以同时基线分离5种标准蛋白,而且通过改变温度可以有效地将3种在低温下保留时间重叠的蛋白(细胞色素-C、β-乳球蛋白和核糖核酸酶)完全分离. 相似文献
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亲水单分散聚合物基质阳离子色谱柱的制备及其应用 总被引:2,自引:0,他引:2
以自制5.0 μm单分散大孔亲水交联聚甲基丙烯酸环氧丙酯微球为基质,合成一种新型弱酸性阳离子色谱填料.选用甲烷磺酸作淋洗液,在流速为1.0 mL/min时,对6种无机阳离子(Li+, Na+, NH+4, K+, Mg2+, Ca2+)和有机胺进行了良好分离.考察了淋洗液种类、浓度以及流速对6种无机阳离子分离的影响,选择了合适的色谱分离条件.测得6种离子在一定浓度范围内具有良好的线性关系和低的检出限.将其用于决明茶中阳离子的分析,4种离子在20 min内完全分离,各离子标准加入回收率在96%~107%之间.此色谱柱的分离效果与Dionex IonPacCS12A商品柱接近,但分析时间缩短了44 min. 相似文献
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Miyabe K 《Journal of chromatography. A》2008,1183(1-2):49-64
Chromatographic performance of various separation media having different structural characteristics as the stationary phase for fast HPLC was quantitatively evaluated by using the new moment equations recently developed with considering the shape and porous structure of the packing materials. Four types of separation media, i.e., full-porous, partially porous (pellicular or shell) type, and non-porous spherical particles and full-porous cylindrical fiber, were chosen as examples. The moment equations were used for predicting the chromatographic behaviors of benzene under hypothetical RPLC conditions. The overall performance of the four types of packing materials as the separation media for fast HPLC was compared with each other from the viewpoint of the peak capacity, which depends on both the retention equilibrium and the mass transfer kinetics. It seems that the full-porous cylindrical fiber and the pellicular type spherical particle are more preferable than the others, i.e., the full-porous and non-porous spherical particles. Now we can use the new moment equations for the quantitative prediction of the chromatographic behaviors of the various packing materials on the basis of a related experimental information and for the evaluation of their performance from various chromatographic points of view. The new moment equations are effective not only for the detailed analyses of chromatographic behaviors but also for the preliminarily evaluation of new types of separation media for fast HPLC. 相似文献
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Micron-sized, monodispersed, poly(methyl methacrylate) (PMMA)/polystyrene (PS)/PMMA/PS multilayered composite particles were
successfully produced by three-step seeded dispersion polymerizations in methanol/water media. The first seeded dispersion
polymerization was carried out with 2-μm-sized, monodispersed PMMA particles. 相似文献
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The thin-layer chromatographic behavior of alkaline earth metal ions (Mg2+, Ca2+, Sr2+, and Ba2+) in aqueous sodium perchlorate solutions on silica gel thin-layers impregnated with sodium hydroxide has been surveyed as a function of salt concentration. At salt concentrations above 2 mol 1(-1), the selectivity of the metals increased with a decrease in the crystal ionic radii; with further increases in salt concentration, the selectivity differences among the metals expanded remarkably. In the present systems, it was supposed that the cation exchange, the surface complexation, and the salting-out effect participate simultaneously in the adsorption of the metals on silica gel. Typical chromatograms for the mutual separation of the alkaline earth metals are presented. 相似文献
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Maximization of peak capacity is a very important step in developing one-dimensional separations of complex samples. In recent work, it was shown that the use of small particles in combination with the new technique of ultrahigh pressure liquid chromatography (UHPLC) was able to generate very high peak capacities. Here we show the ability of conventional HPLC instrumentation to give comparable peak capacities to those obtained in UHPLC for the important case of complex mixtures of peptides but at much lower pressures by using a 60 cm long set of columns packed with 5 microm pellicular (superficially porous) particles. We first show, in complete agreement with the well known results of the theory of isocratic separations that, when time is not limiting, the best peak capacities in gradient elution chromatography are obtained by using large particles and the longest column that can be operated at the pump's pressure limit. Two different types of 5 microm particles (superficially porous and totally porous) were compared for their efficiency in gradient chromatography of peptides. We find that the pellicular material gave about 50% higher peak capacity compared to the analogous porous material. A 60 cm column set packed with pellicular particles was made by connecting short columns in series; a peak capacity of about 460 was obtained in 4 h at room temperature. Increasing the column temperature to 70 degrees C reduced the analysis time to 2 h and further increased the peak capacity to more than 500. The number of peaks observed in the separation of bovine serum albumin tryptic peptides was greatly increased and the separation quality was significantly improved. 相似文献
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Hassan MS Villiéras F Razafitianamaharavo A Michot LJ 《Langmuir : the ACS journal of surfaces and colloids》2005,21(26):12283-12289
Textural and energetic proprieties of kaolinite were studied by low-pressure argon adsorption at 77 K. The heterogeneity of four kaolinites (two low-defect and two high-defect samples) modified on their surface by cation exchange with Li+, Na+, or K+ was studied by DIS analysis of the derivative argon adsorption isotherms. The comparison between the derivative adsorption isotherms shows that the nature of the surface cation influences the adsorption phenomena on edge and basal faces. In the case of basal faces, two adsorption domains are observed: for the first one, argon adsorption is slightly sensitive to the nature of the surface cation; for the second one, argon adsorption energy depends on the nature of surface cation suggesting their presence on theoretically uncharged basal faces. This study also shows that the shape of elementary particles, as derived from basal and edge surface areas, changes with the nature of cation. This anomalous result is due to the decrease of edge surface area with increasing the size of the cation. This surface cation dependence can be accounted for the area occupied by the edge surface cations in the first argon monolayer. 相似文献
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烧制电子陶瓷用的SrTiO_3粉料不仅要求纯度高,而且对粒子的尺寸及均匀性也有严格要求。目前虽可用喷雾沉淀等方法制得尺寸为微米级的SrTiO_3粒子,但其形状与尺寸很不规整。用通常的均分散体系制备方法曾制得均分散BaTiO_3粒子,但由于制备溶液的浓度太低,难以实现工业化。其实,反应溶液浓度低、反应时间长、控制条件严格是大规模制备均分散粒子的共同弱点。本工作提出了一种简便、快速制备均分散SrTiO_3粒子的方法,有望实现均分散粒子制备的工业化。 相似文献
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The relative stability of alkaline earth metals (M2+ = Mg2+, Ca2+, Sr2+, and Ba2+) and their chloride complexes in aqueous solution is examined through molecular dynamics simulations using a flexible SPC water model with an internally consistent set of metal ion force field parameters. For each metal-chloride ion pair in aqueous solution, the free energy profile was calculated via potential of mean force simulations. The simulations provide detailed thermodynamic information regarding the relative stability of the different types of metal-chloride pairs. The free energy profiles indicate that the preference for contact ion pair formation increases with ionic radius and is closely related to the metal hydration free energies. The water residence times within the first hydration shells are in agreement with residence times reported in other computational studies. Calculated association constants suggest an increase in metal-chloride complexation with increasing cation radii that is inconsistent with experimentally observed trends. Possible explanations for this discrepancy are discussed. 相似文献