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991.
酚类在聚醚醚酮上的分离行为研究于剑锋,吴通好,孙家(吉林大学化学系,理论化学研究所,长春,130023)关键词:气相色谱固定相,聚醚醚酮,分离,酚类化合物聚醚醚酮[Poly(ether-ether-ketone),简称PEEK]是近年来推出的一种新型...  相似文献   
992.
Summary A rapid method is described for the determination of hydrocarbon groups in coal liquids. Analysis is carried out by high-performance liquid chromatography on a LiChrosorb NH2 column with n-hexane as the mobile phase. The separation is controlled only by the number of double bonds in a given hydrocarbon molecule. It is essentially independent of the molecular mass for a large variety of compounds investigated. Example of the separation of hydrogenated derivatives of anthracene and of a coal liquid fraction are presented.  相似文献   
993.
合成了对一叔丁基杯[4]芳烃高效液相色谱键合固定相,分离了多环芳烃、硝基苯胺位置异构体、苯甲酸酯、邻苯二甲酸酯和苯的单官能团化合物;比较了在不同的流动相中分析物的保留行为,发现该键合相具有明显的反相特征,对位置异构体的分离优于C18柱,并讨论了可能的分离机理。  相似文献   
994.
The derivatives of pyrazolone are important class of antipyretic and analgesic compounds1. 1-Phenyl-3-methyl-4-arylmethylene-5-pyrazolones are very useful inter- mediates in the synthesis of substituted pyrazolones, generally, which were prepared by the c…  相似文献   
995.
本文用十二烯基丁二酸(DSA)改性氧化锆得到一种新的锆基质色谱固定相。改性前后的红外光谱的差异表明,DSA以两个羧基与氧化锆结合,由于多位点结合方式提高了固定相的稳定性,因此固定相可以在碱性(pH8.5)条件下稳定使用。锆基质色谱固定相具有较强的疏水性,用于中性及碱性化合物的分离取得了满意的结果。  相似文献   
996.
A crosslinkable biphenylmethylpolysiloxane stationary phase was synthesized for capillary column gas chromatography and compared with methyl, phenyl, and cyanopropyl polysiloxane stationary phases for the separation of isomeric polycyclic aromatic compounds. While the new phase gave similar separations of nonpolar isomers when compared to the nonpolar phases, separations of polar isomers were greatly improved because of the induced polarity of the biphenyl group of the stationary phase by the solute molecules. This polarizable stationary phase offers a unique selectivity which is not available in other stationary phases.  相似文献   
997.
A comparative study was performed on heparin resins and strong and weak cation exchangers to investigate the pH dependence, efficiency, binding strength, particle size distribution, static and dynamic capacity, and scanning electron microscopy pictures of chromatographic resins. The resins tested include: Heparin Sepharose FF, SP Sepharose FF, CM Sepharose FF, Heparin Toyopearl 650 m, SP Toyopearl 650 m, CM Toyopearl 650 m, Ceramic Heparin HyperD M, Ceramic S HyperD 20, and Ceramic CM HyperD F. Testing was performed with four different proteins: anti-FVII Mab (IgG), aprotinin, lysozyme, and myoglobin. Dependence of pH on retention was generally very low for proteins with high isoelectric point (pI), though some decrease of retention with increasing pH was observed for CM Ceramic HyperD F and S Ceramic HyperD 20. Binding of anti-FVII Mab with pI < 7.5 was observed on several resins at pH 7.5. Efficiency results show the expected trend of increasing dependence of the plate height with increasing flow rate of Ceramic HyperD resins followed by Toyopearl 650 m resins and the highest flow dependence of the Sepharose FF resins corresponding to their pressure resistance. Determination of particle size distribution by two independent methods, coulter counting and SEM, was in good agreement. Binding strength of cation-exchange resins as a function of ionic strength varies depending on the protein. Binding and elution at high salt concentration may be performed with Ceramic HyperD resins, while binding and elution at low salt concentration may be performed with model proteins on heparin resins. Employing proteins with specific affinity for heparin, a much stronger binding is observed, however, some cation exchangers may still be good substitutions for heparin resins. Dynamic capacity at 10% breakthrough compared to static capacity measurements and dynamic capacity displays that approximately 40-80% of the total available capacity is utilized during chromatographic operation depending on flow rate. A general good agreement was obtained between results of this study and data obtained by others. Results of this study may be used in the selection of resins for testing during protein purification process development.  相似文献   
998.
采用水溶性三(间-磺酸钠苯基)膦(TPPTS)作稳定剂, 在离子液体1-丁基-3-甲基-咪唑四氟硼酸盐([BMIM]BF4)或1-丁基-3-甲基-咪唑对甲基苯磺酸盐([BMIM][p-CH3C6H4SO3])介质中用氢气还原RuCl3·3H2O, 得到钌纳米粒子. 将此钌纳米粒子与(1S, 2S)-1,2-二苯基乙二胺(简称(1S, 2S)-DPEN)、KOH在离子液体/异丙醇介质中原位生成一种不对称加氢催化剂, 用于催化苯乙酮及其衍生物的不对称加氢反应. 实验结果表明, 离子液体介质中的纳米钌催化剂体系具有良好的催化活性和对映选择性. 在优化反应条件下, 催化苯乙酮获得了100%的转化率和79.1%的对映选择性. 并且产物经正己烷萃取后, 含有钌纳米粒子的离子液体可以循环使用.  相似文献   
999.
Three n-octadecylphosphonic acid-modified magnesia-zirconia reversed stationary phases (C18PZM) are prepared via the strong Lewis base interactions between organophosphonate and magnesia-zirconia composite. And two of them are end-capped by using trimethylchlorosilane as end-capping agent in different procedures. Stability studies at extreme high pH conditions (pH 9-12) show that both the non-endcapped and endcapped columns are quite stable at pH 12 mobile phase. The reversed-phase liquid chromatographic behavior of three C18PZM stationary phases are comparatively investigated in detail using a variety of basic compounds as probes. The retention of basic compounds on the three phases is studied over a wide range of pHs. And the possible retention mechanisms of basic compounds on the three stationary phases are discussed. The results show that the basic solutes retain by a hydrophobic and cation-exchange interaction mixed mechanism on three stationary phases when they are operated in eluents at pH values near to the pKa of the Brönsted conjugate acid form of the analyte, suggesting that inherent zirconol groups on ZM are not expected to interact with bases via cation-exchange interaction at lower pH. Nonetheless, the non-endcapped phase differs markedly from the edncapped ones in retention and selectivity of basic solutes using eluents at pH 4.1, implying a complex retention mechanism at this pH. The cation-exchange sites under such conditions are more likely due to the adsorbed Lewis base anionic buffer constituents (acetate) on accessible ZM surface sites than the chemisorbed phosphonate. Although the three phases exhibit very similar chromatographic behavior with eluents at pH 10.1, and show in general satisfactory separation of basic compounds and alkaloids studied, the performance for a specific analyte, however, differs largely from column to column.  相似文献   
1000.
发展了用咪唑离子液体作为流动相添加剂的亲水作用色谱-间接紫外检测四丁基磷和四丁基铵的分析方法。研究了咪唑离子液体、吡啶离子液体作为流动相添加剂对四丁基磷和四丁基铵分析的影响,考察了咪唑离子液体的浓度、有机溶剂含量、检测波长等因素的影响,并讨论了离子液体的作用。采用亲水作用色谱柱,以乙腈-1.0 mmol/L 1-乙基-3-甲基咪唑四氟硼酸盐(体积比60∶40)为流动相,在色谱柱温度30℃,流速1.0 mL/min,紫外检测波长210 nm条件下,四丁基磷和四丁基铵离子在15 min内得到完全分离。检出限为1.0~1.2 mg/L,线性和重现性良好。将此方法应用于松花江水样品和克音河水样品的分析,加标回收率为95.9%~107%。该方法简单,易于应用。  相似文献   
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