共查询到19条相似文献,搜索用时 171 毫秒
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超支化聚合物化学键合毛细管电泳柱的制备及其对蛋白质的分离行为 总被引:1,自引:0,他引:1
分别合成了以三羟甲基丙烷和季戊四醇为核的超支化聚(胺-酯),并对其进行了红外测定、羟值测定、粘度测定等表征。采用化学键合方法将其涂于毛细管内壁,并测定涂层柱的电渗流以及对碱性蛋白质的分离能力,结果表明,涂层柱能有效地抑制碱性蛋白质在毛细管内壁上的吸附,大大降低电渗流;以三羟甲基丙烷为核的超支化聚(胺-酯)涂层柱的塔板数达105/m,而以季戊四醇为核的超支化聚(胺-酯)涂层柱的分离柱效更高,塔板数达107/m。实验结果表明这两类涂层柱都具有较好的分离效果和稳定性。 相似文献
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合成了3种不同支化度的超支化聚醚,采用化学键合的方法将其涂覆于石英毛细管电泳柱内壁,制备了一种新型的毛细管电泳涂层柱。利用该涂层柱通过胶束电动毛细管色谱在线推扫富集技术对6种有机磷农药进行了富集和检测。结果表明:由于超支化聚醚涂层柱显著降低了电渗流,其富集倍数远高于未涂层柱,有效提高了检测的灵敏度。其中支化度为0.43的S3涂层柱的富集倍数高达530倍,是未涂层柱的4倍。利用S3涂层柱建立了分析6种有机磷农药的方法,检出限为0.03~0.08mg/L;加标回收率为85.8%~104.6%;RSD为3.0%~8.4%。此超支化聚醚涂层柱的稳定性良好。 相似文献
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以聚乙烯吡咯烷酮(PVP)为添加剂对毛细管柱进行动态修饰,用于碱性蛋白分离。对4种碱性蛋白质进行分离,实验结果表明聚乙烯吡咯烷酮能够很好地抑制电渗流(EOF)及碱性蛋白在石英毛细管壁上的吸附作用。在pH4.0,PVP浓度(W/V)为0.4%时,EOF仅为1.35×10~(-9) m~2/V.s,平均柱效可达5×10~5理论塔板数/m。每次运行之间(n=6),天与天之间(n=6),迁移时间的相对标准偏差(RSD%)分别小于1%和3%,表明该动态涂敷方法具有良好的重现性和稳定性。另外,由于PVP的粘度较小,使得该方法操作方便、快捷。 相似文献
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《分析科学学报》2020,(2)
本文通过原位聚合反应合成了一种基于纤维状二氧化硅纳米(fSiO_2)和聚合物(DMAEMA polymer)的材料(P-fSiO_2),将该材料采用物理吸附的方式涂覆到毛细管内壁,制备了新型的毛细管电色谱开管柱(P-fSiO_2开管柱),并将其应用于磺胺类物质的开管毛细管电色谱(OT-CEC)分离分析。P-fSiO_2开管柱的制备方法简便快捷、涂层稳定、重复性好,其中日内相对标准偏差(RSD)值小于4.3%(n=6),日间RSD小于4.9%(n=6),柱间RSD为2.2%(n=5)。通过对缓冲溶液浓度、pH值以及分离电压等因素的考察,可以实现对8种磺胺类化合物的良好分离,其中磺胺喹恶啉(SQX)的柱效高达228 542 N/m。 相似文献
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聚倍半硅氧烷复合超支化聚酯的结构及相容性 总被引:1,自引:0,他引:1
以三羟甲基丙烷(TMP)为内核, 二羟甲基丙酸(DMP)为支化单元用准一步法合成了重均分子量为12100的第四代端羟基脂肪族超支化聚酯G4, 并与聚甲基三乙氧基硅烷(PMSQ)共混制备出一系列不同质量分数的复合物. 利用固体核磁共振(NMR)等方法表征了各个样品的结构和反应程度, 并通过测量1H T1ρ值发现超支化聚酯与聚倍半硅氧烷之间具有较好的相容性, 相容尺寸为3~5 nm. 相似文献
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《功能高分子学报》2020,(2)
以M_n=250的聚乙二醇二丙烯酸酯为A_2单体(含有两个A基因的单体,其余类推),N-乙基乙二胺为B'B_2单体,利用丙烯酸酯基和胺基的迈克尔加成聚合反应,一锅法合成了表面含丙烯酸酯键、骨架含聚乙二醇(PEG)、内部含叔胺的具有三维椭球状结构的超支化聚酯胺,并研究了其聚合动力学。利用咪唑对超支化聚酯胺进行改性,并初步研究了咪唑改性的超支化聚酯胺的pH响应性和水溶性。利用核磁共振氢谱、红外光谱、凝胶渗透色谱、GPC-MALLS多角度激光散射系统表征了超支化聚酯胺的分子结构和化学组成。结果表明:聚乙二醇链段的引入能够赋予超支化聚酯胺水溶性;咪唑的引入有利于提高超支化聚酯胺的pH响应性。 相似文献
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Joanna Witos Mikko Karesoja Erno Karjalainen Marja‐Liisa Riekkola 《Journal of separation science》2013,36(6):1070-1077
[2‐(Methacryloyl)oxyethyl]trimethylammonium chloride was successfully polymerized by surface‐initiated atom transfer radical polymerization method on the inner surface of fused‐silica capillaries resulting in a covalently bound poly([2‐(methacryloyl)oxyethyl]trimethylammonium chloride) coating. The coated capillaries provided in capillary electrophoresis an excellent run‐to‐run repeatability, capillary‐to‐capillary and day‐to‐day reproducibility. The capillaries worked reliably over 1 month with EOF repeatability below 0.5%. The positively charged coated capillaries were successfully applied to the capillary electrophoretic separation of three standard proteins and five β‐blockers with the separation efficiencies ranging from 132 000 to 303 000 plates/m, and from 82 000 to 189 000 plates/m, respectively. In addition, challenging high‐ and low‐density lipoprotein particles could be separated. The hydrodynamic sizes of free polymer chains in buffers used in the capillary electrophoretic experiments were measured for the characterization of the coatings. 相似文献
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Benavente F Sanz-Nebot V Barbosa J van der Heijden R van der Greef J Hankemeier T 《Electrophoresis》2007,28(6):944-949
In this study, the potential of poly(methylmethacrylate) (PMMA, Plexiglas) and polyether ether ketone (PEEK) tubing for CE-ESI-MS separations of anions at high pH values was examined. A set of model compounds of biological interest was used to investigate the main operational parameters for CE-ESI-MS, such as the sheath-flow interface design, the polarity of the ionization voltage, the use of ammonia-based separation electrolytes, and the sheath liquid composition. Optimum separations and detection sensitivities in negative ESI mode were obtained using a running electrolyte of 75 mM of ammonia at pH 11 and a sheath liquid of 60:40 v/v or 75:25 v/v isopropanol/water with 0.5% v/v of ammonia. At these experimental conditions, PMMA and PEEK capillaries show good hydrolytic stabilities and lower EOF values than fused-silica columns. Better separation resolutions were obtained with PMMA capillary, but this plastic rapidly swelled and bled because of its limited chemical resistance to the sheath liquid. PMMA columns equipped with a fused-silica tip were used for a safer exposure to the sheath liquid, but the inner surface of the fused-silica tips had limited stability at pH 11. On the other hand, good separations and reproducibility on migration times and peak areas were obtained using PEEK capillaries without capillary column deterioration. 相似文献
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Mixed cationic/anionic surfactants for semipermanent wall coatings in capillary electrophoresis 总被引:1,自引:0,他引:1
Mixtures of the cationic surfactant cetyltrimethylammonium bromide (CTAB) with the anionic surfactant sodium dodecyl sulfate (SDS) form more stable coatings in fused-silica capillaries than CTAB alone. The reversed electroosmotic flow (EOF) generated by CTAB/SDS mixtures remains stable for over 80 min after removal of the surfactants from the buffer. Enhanced stability (relative to CTAB alone) was found even when the ratio of SDS to CTAB was as low as 1%. This greater coating stability is attributed to the structural transition from adsorbed micelle to bilayer, which is induced by addition of SDS. Separation of a mixture of basic proteins yielded efficiencies of 364 000-562 000 plates/m and recoveries ranging from 85% to 98%. Migration time reproducibility was less than 0.9% relative standard deviation (RSD) from run to run and less than 2.6% RSD from day to day. 相似文献
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A novel open-tubular capillary electrochromatography (OTCEC) column was prepared by immobilizing dodecanethiol gold nanoparticles on prederivatised fused-silica capillary columns with sol-gel technology. 3-Mercaptopropyl-trimethoxysilane (MPTMS) was selected as sol-gel precursor to develop a sol-gel layer on the inner wall of the capillary, prior to assembly of dodecanethiol gold nanoparticles onto the generated sol-gel layer through specific interaction between the gold nanoparticles and surface terminating thiol groups. The electrochromatographic behaviour of the sol-gel gold nanoparticle capillary was compared with a gold nanoparticle capillary prepared via MPTMS surface functionalisation, through variation of the percentage of the organic modifier, pH, and separation voltage. Efficient separation for a "reversed-phase" test mixture of thiourea, naphthalene, and biphenyl and for selected polycyclic aromatic hydrocarbons (PAHs) was obtained on the sol-gel based gold nanoparticle capillaries. OTCEC separations of three selected drug substances (propiophenone, benzoin, and warfarin) were also demonstrated. Scanning electron microscopy was used for the characterization of the sol-gel gold nanoparticle capillary surface. The results confirm that dodecanethiol gold nanoparticles, bound on the sol-gel-based inner layer of fused-silica capillary, can provide sufficient solute-bonded phase interactions for OTCEC with reproducible retention as well as characteristic reversed-phase behaviour. 相似文献
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A series of hyperbranched poly(amine-ester)s based on 1,1,1-trimethylolpropane, methyl acrylate and diethanolamine were synthesized and coated on the inner surface of the fused-silica capillaries by physical adsorption. The most effective coating was the seventh generation hyperbranched poly(amine-ester) coating, which reduced the electroosmotic flow (EOF) greatly and suppressed protein adsorption effectively. The high separation efficiencies for basic proteins were obtained and the coating had a good stability. 相似文献
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The surface chemistry of the inner wall of fused-silica capillaries is one important means to control the magnitude as well as the direction of the electroosmotic flow and the adsorption activity. A method was developed to change the surface characteristics of fused-silica capillaries by binding tentacle-like oligourethane groups onto the inner surface. The electroosmotic flow at a buffer pH of 6-9 was reduced by 15 to 40% compared to that in a bare fused-silica tubing, dependent on the type of coating. Sample adsorption is diminished at the same time resulting in a separation of proteins with higher resolution and good migration time precision. At a pH below 4.5 the electroosmotic flow is reversed into the anodic direction, which offers further possibilities for the separation of positively charged analytes as demonstrated for the separation of aromatic and biogenic amines. 相似文献
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A simple polyelectrolyte multilayer (PEM) coating procedure was used for the development of stable modified capillaries. PEM coatings were constructed in fused-silica capillaries using alternating rinses of cationic and anionic polyelectrolytes. The multilayer coatings investigated in this study consisted of two and twenty layer pairs, or bilayers. A bilayer is one layer of a cationic polymer and one layer of an anionic polymer. Poly(diallyldimethylammonium chloride) was used as the cationic polymer, and the polymeric surfactant poly(sodium N-undecanoyl-L-leucylvalinate) was used as the anionic polymer. Previous studies for both chiral and achiral separations have shown that PEM-coated capillaries have excellent reproducibilities, remarkable endurance, and strong stabilities against extreme pH values when used in open-tubular capillary electrochromatography (OT-CEC). In this study, the stability of the coatings was further investigated after exposure to 0.1 M and 1.0 M NaOH. Structural changes of these coatings were monitored using laser scanning confocal microscopy (LSCM) after flushing the capillaries with NaOH. This technique allowed observation of the degradation of the coatings. Observations are discussed in terms of separations using OT-CEC. Electropherograms obtained from the chiral separation of 1,1'-binaphthyl-2,2'-dihydrogenphosphate in OT-CEC showed a decrease in selectivity and an increase in electroosmotic mobility after long exposure to NaOH. The ability to recover the capillaries by exposure to NaOH was also demonstrated. Measurements of electroosmotic mobility and selectivity showed that 2-bilayer and 20-bilayer PEM coatings could be completely removed from the capillary surface after approximately 3.5 and 9.5 h, respectively, of continuous exposure to 1 M NaOH. 相似文献
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Ghiulendan Aptisa Fernando Benavente Victoria Sanz-Nebot Elisabeta Chirila José Barbosa 《Analytical and bioanalytical chemistry》2010,396(4):1571-1579
Modelling electrophoretic mobility as a function of pH can be simultaneously used for determination of ionization constants
and for rapid selection of the optimum pH for separation of mixtures of the modelled compounds. In this work, equations describing
the effect of pH on electrophoretic behaviour were used to investigate migration of a series of polyprotic amphoteric peptide
hormones between pH 2 and 12 in polybrene-coated capillaries. Polybrene (hexadimethrin bromide) is a polymer composed of quaternary
amines that is strongly adsorbed by the fused-silica inner surface, preventing undesired interactions between the peptides
and the inner capillary wall. In polybrene-coated capillaries the separation voltage must be reversed, because of the anodic
electroosmotic flow promoted by the polycationic polymer attached to the inner capillary wall. The possibility of using polybrene-coated
capillaries for determination of accurate ionization constants has been evaluated and the optimum pH for separation of a mixture
of the peptide hormones studied has been selected. Advantages and disadvantages of using bare fused-silica and polybrene-coated
capillaries for these purposes are discussed. 相似文献