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硫酸钡微晶改性玻璃毛细管柱 总被引:1,自引:0,他引:1
为了更全面地了解硫酸钡微晶改性玻璃毛细管柱的特性,本文重点探讨了这种柱的柱容量,热稳定性以及液膜厚度与柱效能之间的关系,并给出了一些分析实例。 相似文献
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聚二甲基硅氧烷溶胶凝胶气相毛细管柱与传统毛细管柱的柱容量比较 总被引:4,自引:1,他引:4
将十一烷和荧蒽分别注入溶胶 凝胶法涂渍的聚二甲基硅氧烷气相毛细管柱和传统的聚二甲基硅氧烷毛细管柱并测量柱效率。在注射量增加到一定程度以后,柱效率迅速下降。能引起柱效率下降10%的注射量称之为柱容量。实验结果表明溶胶 凝胶聚二甲基硅氧烷柱的柱容量远高于传统聚二甲基硅氧烷柱的柱容量。对溶胶 凝胶聚二甲基硅氧烷柱有较高柱容量的原因进行了探讨。 相似文献
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本工作研究了强极性OV-275固定液可以直接涂渍在硅膜改性弹性玻璃毛细管上,研制的柱子具有良好的色谱特性。该柱的柱效,惰性以及热稳定性均优于弹性石英毛细管柱。 相似文献
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弹性玻璃毛细管柱的出现为毛细管色谱技术提供了一种新型柱。最近我们应用硅膜改性法成功地惰化了弹性玻璃毛细管柱而不损害其强度,使这种柱型有了良好的发展基础。关于交联弹性石英柱的制备巳有不少研究,但在硅膜改性玻璃毛细管柱上进行交联的工作尚未见报道。本文介绍SE-54弹性玻璃毛细管交联柱的制备和性能研究。在拉制好的 相似文献
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大孔径厚膜非极性玻璃毛细管柱的制备 总被引:1,自引:0,他引:1
自1959年Desty等人发明0.2—0.3mm内径玻璃毛细管柱以来,玻璃毛细管柱在柱效、惰性、热稳定性和分析速度等方面都取得了重大进步。但原来的玻璃毛细管柱有局限性:样品容量低,需分流进样;宽沸程样品分流易失真,难以精确定量。 大孔径玻璃毛细管柱弥补了上述不足,其特点是:增大柱负荷,消除分流直接进样,定量准确;可调节膜厚,仍保持柱高效、惰性;分析速度快;简化操作,便于推广。因此,大孔径毛细管柱得到人们的普遍重视。 近年来,有关大孔径毛细管柱的文章不少,但对其制柱工艺未作详细报道。19T5年H.T.Badings报道了用软、硬玻璃制备内径0.7—0.9mm,外径1.2—1.4mm毛细管柱,并指出:用静态法涂渍要小心避免气泡。 相似文献
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本文工作研究了极性、强极性固定液直接涂渍在硅膜改性弹性玻璃毛细管内壁上,经优化温度老化色谱柱,成功地研制出OV-225,DEGS,Silar5,Silar9,Silar10等硅膜改性弹性玻璃毛细管柱,各种柱子均具有柱效高,热稳定性好的色谱性能。 相似文献
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变径毛细管柱GC/FTIR联用技术的研究 总被引:1,自引:0,他引:1
本文介绍了使用新型变径毛细管柱的气相色谱/傅里叶变换红外光谱联用技术(GC/FTIR)。以正构烷烃的混合物为样品,研究了载气速流、色谱进样量及柱后死体积对联用效果的影响。分别在变径毛细管柱GC/FTIR和普通毛细管柱GC/FTIR联用系统上分析了烷烃芳烃混合物和合成汽油样品,并利用软件系统提供的程序和红外标准谱库对所得光谱进行了检索。实验结果表明,变径毛细管柱GC/FTIR系统具有色谱进样量大,可鉴定组分多,分离能力强和检测灵敏度高等显著优点。 相似文献
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Packed capillary column solvating gas chromatography (SGC) and open tubular column gas chromatography (GC) were compared with respect to their potentials for fast separations. A recently introduced "universal" peak capacity equation was used to compare the performance of these two methods. The effects of various factors on peak capacity were investigated. Results demonstrate that retention factor and column efficiency are the main factors affecting peak capacity for fast separations. Packed columns produce both high retention factors and high selectivities. While high efficiencies and high peak capacities can be demonstrated by both techniques, open tubular column GC can surpass packed capillary column SGC in both measurements, except for the case of the analysis of simple mixtures in short analysis times, where retention factor and selectivity become important. Practical aspects such as pressure drop and sample capacity are compared for SGC and open tubular column GC. It was found that packed column SGC demonstrates higher sample capacities, but requires much higher column inlet pressures than open tubular column GC. A variety of mobile phases can be used for packed column SGC, which can provide high solvating power for large and polar compounds. 相似文献
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Compositional studies of high-temperature coal tar by GC/FTIR analysis of light oil fractions 总被引:1,自引:0,他引:1
Summary A method for determination of the composition of the light oil fractions in high-temperature coal tar by means of distillation, followed by gas chromatography on a crosslinked fused-silica, capillary column coated with optimum amount of stationary phase and identification by capillary gas chromatography/Fourier transform infrared spectrometry combined with GC retention indices (GC/FTIR-RI) is described. This method was effectively used to identify complex mixture such as coal tar without any standard samples, especially, adapted for isomeric compounds. More than 60 and 50 compounds were also separated and identified respectively in light oil fractions. This shows the capability of the capillary GC/FTIR combined with GC retention indices to identify isomers not accomplished by GC/MS. 相似文献
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双柱串联色谱一次分析甲烷部分氧化制合成气产物 总被引:6,自引:0,他引:6
采用PorapakN色谱柱,延迟空管和13X分子筛色谱柱串联方法,用一个TCD,通过AnaStar色谱工作站实时采集信号进行在线分析,可成功地一次性和分析POM产品气听CH4,CO,CO2,O2等几处可能组分,消除了两台色谱仪无法同时取样分析和在两个不同TCD检测器上采集数据引起的实验误差,提高了分析的可靠性。 相似文献
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A new, versatile, and low cost on-line LC-GC interface has been devloped for the fast and reliable introduction of large volume samples into a cappillary GC column without using the conventional retention gap. PAHs in soot were analyzed by on-line normal phase HPLC-capillary GC. A glass, vial-shaped on-line concentrator provides a zone for solvent evaporation and sample concentration. Large volumes of HPLC eluate can be concentrated with the on-line concentrator and then transferred directly into the cappillary column. Trace levels (< 10 ppb) of PAH compounds can be efficiently concentrated with the on-line concentrator and determined without loss or contamination. 相似文献
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S. L. Smith 《Journal of separation science》1985,8(8):385-387
A dual oven gas chromatograph incorporating a micro, mechanical switching valve has been interfaced to an FTIR spectrometer. With this system, each oven can be operated with independent temperature control. Complete choice of the columns' type and capacity gives flexibility in the separation prior to spectroscopic evaluation. An application which demonstrates some of the advantages of column switching in GC/FTIR is presented. Minor sample components have been successfully analyzed by heart-cutting the appropriate section of the separation from a high to a low capacity column. In this way, the dynamic range of the technique is effectively increased while an efficient chromatographic inlet to the FTIR is maintained. 相似文献
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A multibed on-line sorption trap is used to preconcentrate organic vapors from air samples and inject the analytes into a GC separation column. Injection plug widths depend on the boiling point for the lipophilic compounds and on the polarity and boiling point for the polar compounds. Injection plug widths are sufficiently small (0.7-0.8 s) as to allow the direct injection of the most volatile compounds into the GC column without the need for a second focusing device. The presence of water in the samples has an effect on the retention of polar compounds by the trap. However, this effect is reproducible for a fixed water content and so can be overcome by using calibration standards under the same conditions of humidity as the samples. The thermal decomposition of many volatile organic compounds in an on-line sorption trap during the GC analysis of air samples is examined. The results show that degradation of unstable compounds is governed by the amount of heat transferred to the compounds during desorption (i.e., applied temperature and pulse duration). The use of an on-line trap results in the immediate transfer of desorbed compounds to the analytical column, which can reduce the formation of artifacts. 相似文献
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Three commercially available chiral capillary columns, Chirasil-Dex, BGB-176SE, and BGB-172, have been evaluated for the separation into enantiomers of the 19 chiral polychlorinated biphenyls (PCB) congeners stable at room temperature. The enantiomers of 15 chiral PCBs were, at least to some extent, separated using these beta-cyclodextrin based columns. Multidimensional techniques, such as heart-cut multi-dimensional gas chromatography (heart-cut MDGC) and comprehensive two-dimensional gas chromatography (GC x GC), were investigated for their ability to solve coelution problems with other PCBs present in commercial mixtures and real-life samples. Heart-cut MDGC improved the separation as compared to one-dimensional GC, and enantiomeric fractions of the investigated chiral PCBs could be determined free from interferences. However, limitations on the number of target compounds that can be transferred to the second column in a single run and, therefore, the time consumption, have led to the evaluation of GC x GC as an alternative for this type of analysis. With GC x GC, two column set-ups were tested, both having a chiral column as first-dimension column, and two different polar stationary phase columns in the second dimension. On using both column combinations, congeners 84, 91, 95, 132, 135, 136, 149, 174, and 176 could be determined free from coelutions with other PCBs. Results on the application of heart-cut MDGC to food samples such as milk and cheese are given, as well as the first results on the application of GC x GC to this type of samples. 相似文献
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全二维气相色谱技术及其进展 总被引:37,自引:2,他引:35
许多分析问题的解决需要得到比一维色谱技术能提供的更高的分辨率。分离能力可通过使用多种分离技术或机理的组合来增强。此时 ,样品被分散在不同的时间维 ,最终的分辨率强烈地依赖于这些维间分离特性的差异。当它们之间没有关联 ,也即相互间正交时 ,系统可获得最高的分辨率。全二维气相色谱 (GC×GC)提供了一个真正的正交分离系统。它把分离机理不同而又互相独立的两支色谱柱以串联方式结合组成二维气相色谱。在这两支色谱柱之间装有的一个调制器起捕集再传送的作用。全二维色谱的峰容量为组成它的两支色谱柱各自峰容量的乘积。 相似文献
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A major challenge in metabolomics analysis is the accurate quantification of metabolites in the presence of (extremely) high abundant metabolites. Quantification of metabolites at low concentrations can be complicated by co-elution and/or peak distortion when these metabolites elute close to high abundant metabolites. To increase the separation efficiency a comprehensive two-dimensional gas chromatographic-mass spectrometric method (GC x GC-MS) was set up, in which a polar first dimension column and an apolar second dimension column were used to maximize the peak capacity. The feasibility of using wider bore, thicker film columns in the second dimension to improve the mass loadability and inertness of the analytical system was investigated. Several column combinations with varying second dimension column dimensions were compared with a setup with a narrow bore column (0.1mm I.D.) in the second dimension. With a wider bore column (0.32 mm I.D.) in the second dimension the mass loadability was improved 10-fold, and the more inert column surface of the thicker film second dimension column resulted in a more accurate (automated) quantification and improved linearity in the presence of high concentrations of matrix compounds or metabolites. These benefits amply compensated the observed decrease in peak capacity of 40% compared to the narrow bore (0.1mm I.D.) thin film second dimension column. Compared to GC-MS and conventional GC x GC-MS, better performance for quantification of metabolites for typical metabolomics samples was achieved. 相似文献