新型聚合物多孔涂层毛细管开管柱的制备及电色谱研究

以甲基丙烯酸缩水甘油酯(GMA)和乙二醇二甲基丙烯酸酯(EDMA)为前驱体制备了新型聚合物多孔涂层毛细管开管(PLOT)柱固定相。通过优化聚合反应时间、致孔剂比例及交联剂比例获得了色谱性能良好的PLOT柱,扫描电镜结果显示毛细管柱内的多孔涂层厚度适中且均匀。在毛细管电色谱模式下,PLOT柱以反相色谱分离机理有效分离了中性、酸性和碱性小分子。人血清白蛋白(HSA)共价结合的蛋白亲和PLOT柱对5对手性对映体实现了较好的分离,且其分离度远高于HSA修饰的单层聚合物毛细管开管柱。PLOT柱分离烷基苯的日内、日间和柱间的相对标准偏差分别小于1.7%、4.8%和7.8%。     

改性活性碳自组装多孔层毛细管气相色谱柱的研制及其特性评价

采用自组装膜制备技术和超细亚微粒级吸附剂研制高效活性碳多孔层毛细管色谱柱（PLOT），选用K3PO4、K2HPO4和KH2PO4三种不同的磷酸盐对色谱柱进行改性脱活，考察了脱活盐浓度对色谱柱保留行为的影响程度，并采用研制的高效活性碳PLOT毛细管色谱柱对惰性气体和低碳烃（H2、Air、CO、CO2和C1-C4烃）进行了分离分析，结果表明：在高效活性碳PLOT毛细管色谱柱制备工艺中，活性碳吸附剂的最佳粒度为0.5-0.7μm之间；磷酸盐脱活剂的最佳浓度为1.5%，老化时间为250℃；所研制的高效活性碳PLOT毛细管色谱柱对惰性气体和低碳烃具有较好的分离度。     

中国科学院兰州化物所色谱技术研究开发中心

中国科学院兰州化物所色谱技术研究开发中心是我国唯一从事研制、生产高效气相色谱柱,高效液相色谱柱、液相色谱填料以及相关产品的高科技企业。中心致力于我国色谱柱产业核心技术体系的发展、独创出国际领先的液相沉渍、原位一体化合成制备高效PLOT色谱柱技术;拥有先进的超净-静态制备高效WCOT色谱柱技术;     

高效毛细管气相色谱柱

中国科学院兰州化学物理研究所色谱技术研究开发中心长期从事高效毛细管色谱柱的开发及其应用研究。研制生产的各类毛细管色谱柱，质量可靠，品种齐全，价格合理，1988年由中国科学院推荐而被国家机械工业委员会列为“推荐替代进口产品”。本期针对PLOT毛细管色谱柱作特别介绍。     

高效毛细管气相色谱柱

中国科学院兰州化学物理研究所色谱技术研究开发中心长期从事高效毛细管色谱柱的开发及其应用研究。研制生产的各类毛细管色谱柱，质量可靠，品种齐全，价格合理，1988年由中国科学院推荐而被国家机械工业委员会列为“推荐替代进口产品”。本期针对PLOT毛细管色谱柱作特别介绍。     

中国科学院兰州化物所色谱技术研究开发中心

中国科学院兰州化物所色谱技术研究开发中心是我国唯一从事研制、生产高效气相色谱柱、高效液相色谱柱、液相色谱填料以及相关产品的高科技企业。中心致力于我国色谱柱产业核心技术体系的发展,独创出国际领先的液相沉渍。原位一体化合成制备高效PLOT色谱柱技术:拥有先进的超净-静态制备高效WCOT色谱柱技术:在国内率先完成了球形硅胶色谱填料制备研究开发工作,研制开发出多种液相手性分析填料以及国内急需的专用色谱柱,创造出多项     

中国科学院兰州化物所色谱技术研究开发中心

<正>中国科学院兰州化物所色谱技术研究开发中心是我国唯一从事研制,生产高效气相色谱柱.高效液相色谱柱.液相色谱填料以及相关产品的高科技企业.中心致力于我国色谱柱产业核心技术体系的发展.独创出国际领先的液相沉渍。原位一体化合成制备高效PLOT色谱柱技术.拥有先进的超净——静态制备高效WCOT色谱柱技术.在国内率先完成了球形硅胶色谱填料制备研究开发工作.研制开发出多种液相手性分析填料以及国内急需的专用     

原位聚合一体化多孔层开管柱Pora-Q色谱柱的研制

采用全新的两步原位合成法，先通过将带有双活性反应基团γ—三甲氧基硅丙基异丁烯酸酯的CH3-O-Si-基团与石英毛细管内壁表面的Si-0H反应，在石英毛细管内壁键合上带有活性基团的中间有机层，再原位合成多孔聚合物，制成高效一体化Q型聚合物颗粒多孔层开管柱(PLOT)Pora-Q毛细管色谱柱；该色谱柱具有良好的惰性、较强的分离能力；与一般的商品化PLOT-Q色谱柱相比，热稳定性和机械强度有明显的改善和提高，最高使用温度提高了50℃达到300℃，扩展了该种色谱柱的应用范围。     

气相色谱法分析氦中氧气、氮气、一氧化碳、二氧化碳及氙气混合气体标准物质

建立利用气相色谱热导检测器分析气体激光器用氦中氧气、氮气、一氧化碳、二氧化碳及氙气混合气体标准物质的方法。试验比较了不同极性、不同类型的色谱柱,对柱箱温度、载气流量进行了优化,最终确定以HP–PLOT/分子筛色谱柱分离氧气、氮气、一氧化碳、氙气,柱箱温度保持40℃,以HP–PLOT Q柱分离二氧化碳,柱箱温度保持60℃,载气流量均为2 m L/min。在混合气体标准物质量值范围内,该分析方法测定结果的相对标准偏差不大于1%(n=6),对重量法配制得标准气体进行分析比对,测量误差不大于1%。     

中国科学院兰州化物所色谱技术研究开发中心

<正>中国科学院兰州化物所色谱技术研究开发中心是我国唯一从事研制、生产高效气相色谱柱、高效液相色谱柱、液相色谱填料以及相关产品的高科技企业。中心致力于我国色谱柱产业核心技术体系的发展,独创出国际领先的液相沉溃、原位一体化合成制备高效PLOT色谱柱技术;拥有先进的超净-静态制备高效WCOT色谱柱技术;在国内率先完成了球形硅胶色谱填料制备研究开发工作;研制开发出多种液相手性分析填料以及国内急需的专用色谱柱;创造出多项     

整体柱离子色谱的研究进展

该文介绍了离子色谱的分类,整体柱的分类、制备及特点,并以此为依据归纳总结了常规整体柱在离子色谱中的应用和毛细管整体柱在毛细管离子色谱中的应用,其中包括硅胶基质整体柱和聚合物基质整体柱,评述并展望了整体柱离子色谱的发展前景.     

毛细管电色谱柱制备技术的进展

介绍了毛细管电色谱开管柱、填充柱和整体柱的各种制备技术及其优势与不足,特别是对于近期发展的毛细管电色谱整体柱的制备方法及其应用进行了系统综述。引用文献100篇。     

Permeability, porosity, and structure of monolithic capillary columns in gas chromatography

The permeability of monolithic silica gel capillary columns with respect to the helium carrier gas was studied using gas chromatography. The results obtained by gas chromatography and liquid chromatography were found to be in close agreement. The permeability of monolithic capillary columns was compared to that of hollow capillary columns and columns packed with finely dispersed sorbents. It was demonstrated that the permeability of the monolithic capillary columns studied is almost three orders of magnitude lower than that of hollow capillary columns of the same diameter but two orders of magnitude higher than that of columns packed with micron-scale particles. The interstitial fraction of the monolithic columns was found to be very high, 0.95.     

Column selectivity in reversed-phase liquid chromatography. V. Higher metal content (type-A) alkyl-silica columns

Retention measurements involving 16 test solutes have been carried out for 38 type-A alkyl-silica columns and three bonded-zirconia columns. These measurements have been analyzed in terms of a model previously developed for type-B columns, so as to yield values of five column selectivity parameters (H, S*, A, B, C) for each type-A column. Overall differences in selectivity between type-A and -B columns can be related to the average values of H, S*, etc. for each column type. Compared to type-B columns, type-A columns provide generally stronger retention for carboxylic acids, while solutes that are more hydrophobic or less bulky are more retained on type-B columns. Hydrogen-bond acceptors (e.g. aliphatic amides) and cations (e.g. protonated bases) are strongly retained on type-A versus type-B columns. Compared to type-B columns, bonded-zirconia columns show much increased retention of cations and reduced retention of hydrogen-bond acceptors. Because of relatively large differences in the selectivity of bonded-zirconia, type-A, and type-B columns, it will prove difficult to find columns of different type (e.g. a type-A and a type-B column) which have equivalent selectivity. Type-A columns also tend to be more different from each other (in terms of selectivity) than is the case for type-B columns. As a result, the replacement of a given type-A column by an "equivalent" type-A column also appears unlikely, except for samples that do not contain ionized compounds.     

Capillary columns in liquid chromatography: between conventional columns and microchips

Liquid chromatography on columns with small internal diameters has been reviewed as the intermediate technique between conventional liquid chromatography and microchip separations. The development of micro column separations in the early years has been described, starting with the papers of Horváth and co-workers and Ishii and co-workers, continuing into the first part of the eighties, then making a leap in time to recent innovations with small-bore columns. Based on internal diameters a classification of the different analytical HPLC columns has been suggested. The advantages of small-bore columns have been discussed, with particular emphasis on the advantage of coupling to concentration sensitive detectors when the sample amount is limited. Open tubular columns are treated as a part of the historic background. The recent developments include a brief look into the current status of monolithic columns, the use of packed nano columns and micro columns with electrospray mass spectrometry, and the potential of two-dimensional comprehensive liquid chromatography. Finally, the coupling of sample preparation to analytical columns and the future applications of the novel technological improvements to the microchip separation methods have been discussed.     

Preparation and evaluation of polar stabilized phase open tubular (SPOT) columns

Summary A method is described for the routine preparation of high resolution stabilized phase open tubular (SPOT) columns. A finely dispersed siliceous material (Cab-O-Sil) is treated with benzyltriphenylphosphoniumchloride and dynamically coated onto the inside wall of glass capillary columns. Additional dynamics coating with a polar stationary phase yields thermostable columns of high efficiency. The columns show favourable adsorption properties and good long term stability. The mechanical stability of the stationary phase film is explained in terms of the rheological behaviour of concentrated disperisons. The designation PLOT columns appers inapplicable, and these columns will be referred to as SPOT columns. A theoretical model, describing band spreading in SPOT columns, is proposed and compared with the experimental results. Some applications in routine use and in ultra trace analysis are presented.     

Column selectivity in reversed-phase liquid chromatography. VI. Columns with embedded or end-capping polar groups

A previous model of column selectivity for reversed-phase liquid chromatography (RP-LC) has been applied to an additional 21 columns with embedded or end-capping polar groups (EPGs). Embedded-polar-group columns exhibit a significantly different selectivity vs. non-EPG, type-B columns, generally showing preferential retention of hydrogen-bond donors, as well as decreased retention for hydrogen-bond acceptors or ionized bases. EPG-columns are also generally less hydrophobic (more polar) than are non-EPG-columns. Interestingly, columns with polar end-capping tend to more closely resemble non-EPG columns, suggesting that the polar group has less effect on column selectivity when used to end-cap the column versus the case of an embedded polar group. Column selectivity data reported here for EPG-columns can be combined with previously reported values for non-EPG columns to provide a database of 154 different columns. This enables a comparison of any two of these columns in terms of selectivity. However, comparisons that involve EPG columns are more approximate.     

Life-time studies with capillary electrochromatography columns operated under different conditions

A test system has been established to permit the monitoring of the life-time performance of several reversed- phase capillary electrochromatography (CEC) columns. The retention factors, k(cec), peak symmetry coefficients, lambda(sym), and column efficiencies, N, of three neutral n-alkylbenzene analytes, namely ethyl-, n-butyl- and n-pentylbenzenes, were determined for Hypersil 3 microm n-octylsilica and n-octadecylsilica packed into CEC capillary columns of 100 microm I.D., with a packed length of 250 mm, and a total length of 335 mm. The performances of these CEC capillary columns were examined for a variety of eluents with pH values ranging between pH 2.0 - 8.0, similar to those employed to study the retention behaviour of peptides that we have previously reported. The relative standard deviation (RSD) of the retention factors (k(cec) values) of these n-alkylbenzenes, acquired with an eluent of (25 mM Tris-HCl, pH 8.0,)-acetonitrile (1:4, v/v), when the CEC capillary columns were used for the first time (virgin values), were 4% (based on data acquired with 4 CEC capillary columns) for the n-octyl bonded silica capillary columns, and 6% (based on 8 columns) for n-octadecyl bonded silica capillary columns. The RSD values of the k(cec) values of the n-alkylbenzenes for one set of replicates (n=6) with one CEC capillary column was < 0.5%. The theoretical plate numbers, N, for the virgin CEC capillary columns were ca. 60,000, whilst the observed N values for all new CEC capillary columns were > or = 40,000 for n-octyl bonded silica capillary columns and > or = 50,000 for n-octadecyl bonded silica capillary columns. The peak symmetry coefficients, lambda(sym), of the n-alkylbenzenes for virgin CEC capillary columns and for CEC capillary columns used for more than 1,000 injections were always in the range 0.95-1.05. The experimental results clearly document that the life-time performance of the CEC capillary columns depends on the eluent composition, as well as the nature of the analytes to which the CEC capillary columns are exposed.     

Reproducibility of the separation of astaxanthin stereoisomers on Pirkle covalent L-leucine and D-phenylglycine columns.

The reproducibility of the separation of astaxanthin stereoisomers on columns packed with Pirkle covalent L-leucine chiral stationary phase (CSP) was examined by comparing six columns purchased from the same manufacturer. Differences were found even for columns packed with CSP from the same lot. The reproducibility of columns packed with Pirkle covalent D-phenylglycine CSP was also examined by comparing columns purchased from the same manufacturer as well as from different manufacturers. Significant differences were found for columns packed by different manufacturers. Chiral column-to-column reproducibility for complex stereoisomeric separations should therefore not be taken for granted.     

Comparison of the efficiency of microparticulate and monolithic capillary columns

A comparison is made between the efficiency of microparticulate capillary columns and silica and polymer-based monolithic capillary columns in the pressure-driven (high-performance liquid chromatography) and electro-driven (capillary electrochromatography) modes. With packed capillary columns similar plate heights are possible as with conventional packed columns. However, a large variation is observed in the plate heights for individual columns. This can only be explained by differences in the quality of the packed bed. The minimum plate height obtained with silica monolithic capillary columns in the HPLC mode is approximately 10 microm, which is comparable to that of columns packed with 5-microm particles. The permeability of wide-pore silica monoliths was found to be much higher than that of comparable microparticulate columns, which leads to much lower pressure drops for the same eluent at the same linear mobile phase velocity. For polymer-based monolithic columns (acrylamide, styrene/divinyl benzene, methacrylate, acrylate) high efficiencies have been found in the CEC mode with minimum plate heights between 2 and 10 microm. However, in the HPLC mode minimum plate heights in the range of 10 to 25 microm have been reported.