玻璃毛细管气相色谱讲座 第一讲 玻璃毛细管气相色谱的一般知识

玻璃毛细管气相色谱,简称(GC)~2,它是玻璃微填柱、填充毛细管柱和开管柱气相色谱的总称。人们习惯上讲的毛细管柱主要是指1957年 Galay 首创的开管柱。之所以叫开管柱是由于此柱的结构为固定液附着于毛细管的内壁,而管中间留有对载气开放的通道。本文所称毛细管柱即为开管柱。经典的开管柱是将固定液直接涂溃于毛细管内壁(即 WCOT 柱)。Desty 等设计并加工的玻璃毛细管拉制机,为(GC)~2的推广和发展提供了有利的条件。由于玻璃柱对固定液的润湿性差,后来又相继发展了各种壁处理的开管柱(WTOT 柱),其中多孔层开管柱(PLOT 柱)是较理想的柱型之一。载体涂层开管柱(SCO(?) 柱)是 PLOT 柱中最常用的柱型。1979年出现的熔融氧化硅开管柱(FSOT柱)为(GC)~2增添了新的具有柔性和惰性的柱型。毛细管色谱在我国的发展起始于1959年,丁景群等对毛细管色谱的理论及应用做了许多工作,但直到七十年代中后期才有了较快的发展,先后成功地制成了微填柱 WCOT 柱、PLOT 柱、SCOT柱和 FSOT 柱。1980年全国第一届毛细管色谱学术报告会的召开,标志着我国的毛细管色谱研究与应用进入一个新的发展阶段。本讲座共分四讲:玻璃毛细管气相色谱的一般知识;玻璃毛细管柱的制备;毛细管柱的色谱系统;玻璃毛细管气相色谱的应用。由于篇幅原因及作者们的水平所限,文中缺点、错误定所难免,敬希读者指正。     

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。     

氧化石墨烯修饰多孔复合涂层超长开管液相色谱柱的制备与评价

采用原位聚合法在毛细管柱(3 m ×25μm i. d.)内壁制备粗糙结构的聚氯甲基苯乙烯二乙烯基苯涂层,并将氧化石墨烯以共价键合的方式固定在涂层表面,制备成氧化石墨烯修饰多孔复合涂层超长开管毛细管液相色谱柱。通过扫描电镜、透射电镜、拉曼光谱等手段对固定相的结构进行表征,证实聚氯甲基苯乙烯二乙烯基苯涂层具有球形分散结构,而片状的氧化石墨烯均匀覆盖在聚合物层表面。球状的聚合物层及氧化石墨烯的覆盖极大地提高了色谱柱的相比及样品容量,乙腈-水为流动相可分离烷基苯、中性多环芳烃、酸性和碱性化合物,乙腈-0.02 mol/ L 醋酸铵为流动相可实现4种核酸碱基样品的分离。制备的色谱柱具有良好的重复性和稳定性,测试的日内、日间、柱间重复性(n=6)相对标准偏差(RSD)均在0.3%~2.0%范围内。     

微波辅助合成法快速制备替考拉宁开管毛细管电色谱柱

采用微波辅助合成技术,快速制备了以替考拉宁为固定相的开管毛细管电色谱柱。在pH 4.0~7.0的范围内比较了空管与替考拉宁修饰柱的电渗情况,表明替考拉宁开管毛细管电色谱柱有效地降低了电渗。用该色谱柱分离了多种手性对映体,均达到基线分离,体现了替考拉宁开管毛细管电色谱柱良好的分离性能。以DL-色氨酸考察了柱子的稳定性和重现性,结果显示采用微波辅助合成技术制得的替考拉宁开管毛细管电色谱柱具有良好的稳定性和重现性。     

不锈钢高温毛细管色谱柱的研制

〕以甲硅烷高温裂解的方法钝化不锈钢毛细管内表面。用钝化后的柱管制备了涂渍固定液的开管柱(WCOT)和固体吸附剂的多孔层开管柱(PLOT),两种柱子都能在400℃以上的高温操作,并在石油化工分析中得到应用。不锈钢高温毛细管柱的出现,解决了弹性石英毛细柱在高温下容易断裂的问题。     

原位聚合法制备碳十八甲基丙烯酸酯聚合物及其用作开管毛细管电色谱固定相

以十八碳醇甲基丙烯酸酯为单体、乙二醇二甲基丙烯酸酯为交联剂,采用原位聚合法合成了一种新型毛细管开管柱固定相,优化了毛细管开管柱的制备参数。柱内表面的电镜图像显示其具有多孔皱褶、质地均匀的结构特征。将其应用于甲苯、乙苯、丙苯、丁苯、戊苯和己苯的分离试验中,6种化合物达到了完全分离,出峰顺序与它们的疏水性一致,表明该柱有明显的疏水色谱作用。在10 mmol/L磷酸盐(pH 8.5,含50%(v/v)乙腈)流动相、16 kV电压下,该开管柱成功地分离了4种抗癫痫类药物,柱效范围为35300~49800 塔板/m,与空柱管相比分离效果明显提高。结果表明通过本实验的原位聚合法可制备具有反相色谱作用的有机基质碳十八开管毛细管电色谱柱。     

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。     

新型二氧化硅纳米毛细管开管柱的制备及其电色谱性能的研究

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。     

高效多孔层毛细管柱吸附气相色谱的研究进展

PLOT柱是用于永久性气体,低碳烃和挥发性化合物色谱分析的最有效的工具,经常用于替代经典填充柱,对多孔层开管毛细管柱（PLOT）吸附色谱的分离机理、PLOT柱制备方法和各类吸附剂的色谱特性及其特定应用进行了综述。     

原位合成一体化多孔聚合物毛细管色谱柱的研制及其应用

采用全新的两步原位合成法,制备高效一体化U型多孔层聚合物颗粒PLOT Pora-U毛细管色谱柱。先将带有双活性反应基团的γ-三甲氧基硅丙基异丁烯酸酯中的CH3—O—Si—基团与石英毛细管内壁表面的Si—OH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。该色谱柱具有良好的惰性和较强的分离能力。与一般的商品化PLOT-U色谱柱相比,热稳定性和机械强度有明显的改善和提高,色谱柱最高使用温度提高了20 ℃,达到210 ℃,对强极性物质、强活性化合物、永久性气体以及低碳化合物有较好的分     

窄内径多孔层开管柱的制备及在液相色谱中的应用

近年来,微纳分离技术由于其内在的优势而受到越来越多的关注.多孔层开管柱是一种重要的微分离柱形式,与粗内径的多孔层开管柱(>25μm)相比,窄内径的多孔层开管柱具有更高的分离效率和更低的试剂消耗量.本文综述了内径≤25μm的窄内径多孔层开管毛细管柱的制备方法、与质谱检测联用技术以及在液相色谱中的应用研究进展,对其发展前景进行了展望.     

The fabrication of poly (polyethylene glycol diacrylate) monolithic porous layer open tubular (mono‐PLOT) columns and applications in hydrophilic interaction chromatography and capillary gas chromatography for small molecules

The easy shrinkage and swelling of polymer monolithic column when exposed to mobile phase with different polarity is a problem that cannot be ignored. To overcome this drawback, a convenient aqueous two‐phase polymerization approach was used to prepare poly (polyethylene glycol diacrylate, PEGDA) monolithic porous layer open tubular (mono‐PLOT) columns (150 μm). The poly(PEGDA) mono‐PLOT column with homogeneous polymer porous layer was synthesized successfully. A maximum plate number of 41,500 plates per meter for allyl thiourea was obtained under a velocity of 1.8 mm/s. Several kinds of polar molecule were separated on the proposed mono‐PLOT column and a typical hydrophilic interaction retention mechanism was observed. High speed separation of benzoic acids was also carried out, baseline separation of five benzoic acids was successfully achieved within 5 min with a 70 cm mono‐PLOT column at 50°C. Furthermore, the resulting PLOT column was also successfully applied to separate standard analytes of three DNA oxidative damage products and RNA‐modified nucleosides and four chlorophenols. At last, the column could separate alcohols, alkanes, and aromatic isomers via GC. It had more than 20,000 plates per meter for butanol – higher than commercial coatings open tubular columns.     

Stainless steel capillary columns for high temperature gas chromatography

A layer of elemental silicon has been deposited on the surface of stainless steel tubing by means of chemical vapor deposition (CVD). Two kinds of capillary column were prepared from the deactivated tubing: cross-linked, silanol-terminated polydime-thylsiloxane wall coated open tubular (WCOT) columns and molecular sieve 13X porous layer open tubular (PLOT) columns. Unlike fused silica capillary columns, stainless steel WCOT and PLOT columns can be operated at temperatures in excess of 400°C. High temperature simulated distillation has been performed successfully with a macro bore WCOT column and rapid PNA (paraffin, naphthene, and aromatic) analysis with a multidimensional gas solid chromatographic (GSC) system using PLOT columns.     

Chromatographic properties of open tubular columns with an adsorption layer of aerosil

The chromatographic properties of a porous layer open tubular (PLOT) capillary column with an adsorption layer of highly dispersed silicon dioxide (Aerosil) were studied. It was found that the high efficiency and capacity of the column were retained at high rates of a gas-chromatographic process. The test adsorbent is similar to polydimethyl and polyphenylmethyl siloxane stationary phases in terms of selectivity. Complex multicomponent hydrocarbon mixtures can be separated on the PLOT/SiO₂ column because of low peak asymmetry.     

Capillary electrochromatography of amino acids with a protein-bonded porous-layer open-tubular column

A protein-bonded porous-layer open-tubular (PLOT) column has been synthesized and applied to the separation of amino acids by CEC. The porous layer was coated on the capillary inner wall by in situ polymerization of 2-hydroxyethyl methacrylate and 2-vinyl-4,4-dimethylazlactone in the presence of 1-decanol as a porogen inside a fused-silica capillary silanized with gamma-methacryloxypropryltrimethoxysilane. The azlactone functionalities at the surface of the porous polymeric support layer were allowed to react with BSA to yield a protein-bonded PLOT column. This porous layer was characterized by scanning electron microscopy and its thickness was about 1 microm. CEC on this column gave enhanced resolution of three amino acids (histidine, phenylalanine, and tryptophan), and baseline separation was achieved with 20 mM phosphate buffer, pH 8.0.     

基于窄内径多孔层毛细管开管柱的纳流高效液相色谱用于N-衍生化氨基酸对映体的分离

窄内径多孔层毛细管开管柱（NPLOT柱）在生命科学领域,特别是单细胞分析领域具有较好的应用前景。本研究采用原位热引发聚合法来制备窄内径奎尼丁类手性固定相多孔层开管柱,在6 μ m i.d.的毛细管中制备有机聚合物多孔层,考察了不同热聚合时间（3、6和9 h）对NPLOT柱形貌的影响,热聚3 h和6 h制备的NPLOT柱形貌均一,多孔层厚度分别为103±51 nm和210±51 nm。将热聚合3 h制备的NPLOT柱用于纳流高效液相色谱分离N-衍生化氨基酸对映体,在2 min内即可实现基本分离,消耗的样品量仅为皮升级别。该研究将为单细胞分析提供研究手段。     

In-situ Preparation of Integrated Polymeric Pora-U PLOT Columns and their Applications in Gas Chromatography

Summary A new method is described to prepare polymeric porous-layer open-tubular (PLOT) columns by using a two-step in-situ polymerization technology. The integrated method involves a straightforward in-situ polymerization of the monomer. By using -(trimethoxysilyl)propyl methacrylate as a bridge, the porous polymer is bonded to the columns inner wall, and this polymer is crosslinked so the whole polymer looks like a single moleculer. The new column avoids the defects of traditional polymer PLOT columns where particles are easily released and swept through the column, causing blockage or a spiking detection signal. The new type of PLOT column is coated with a divinylbenzene and ethylene glycol dimethyl acrylate copolymer and has an increased polarity when compared to a conventional polymer Q-type PLOT column. The retention characteristics of the new column were evaluated and found to be comparable with the commercially available HP PLOT-U column. The inertness of the porous polymer allows the elution of a range of apolar and polar compounds: even most active and polar compounds such as H₂O and H₂S eluted symmetrically. The new column possesses high stability and can withstand temperatures up to 210 °C. With this new type of capillary columns, significantly better mechanical stability, temperature endurance, reproducibility, strong separation power and good inertness are obtained in combination with short analysis times.     

丙烯腈与二乙烯苯原位聚合制备强极性高聚物涂层毛细管柱

以丙烯腈为单体，二乙烯苯为交联剂，采用原位聚合法制备出了强极性的有机高聚物多孔层开管柱－ＯＰＰＬＯＴ－Ａ型柱。对影响制备的因素如致孔剂的选择，反应温度与反应时间，引发剂的选择及浓度等进行了讨论。应用扫描电镜和红外光谱对形成的高聚物固定相的结构进行了表征。实验表明该柱对腈、醛类等化合物有好的分离性能。     

Porous layer open-tubular column with styrene and itaconic acid-copolymerized polymer as stationary phase for capillary electrochromatography–mass spectrometry

Enhancing the specific surface area of stationary phase is important in chromatographic science, especially in open-tubular column in which the coating only exists on the inner surface. In this work, a porous layer open-tubular (PLOT) column with stationary phase of styrene and itaconic acid-copolymerized polymer was developed. Thermal-initiated polymerization method with strategies like controlling the ratio of reaction reagents to solvents and reaction time, confinement by the narrow inner diameter of capillary were used for preparing the stationary phase with uniform structure and relatively thick layer. Due to the high separation efficiency and capacity, the PLOT column was used for capillary electrochromatography (CEC) separation of multiple groups of analytes like alkylbenzenes, phenyl amines, phenols, vanillins, and sulfonamides with theoretical plates (N) up to 1,54,845 N/m. In addition, due to high permeability of the CEC column and large electroosmotic flow mobility generated by abundant carboxyl groups in the coating material, the PLOT-CEC column was successfully coupled with mass spectrometry (MS) through a sheath flow interface. The developed PLOT-CEC-MS method was used for the analysis of antiseptics like parabens and herbicides like pyridines.     

Open tubular capillary column of 50 μm internal diameter with a very high separation efficiency for the separation of peptides in CEC and LC

A specially designed long open tubular capillary column (50 μm internal diameter and 112 cm effective length) was prepared by fabrication of a thin three‐component co‐polymer layer on the inner surface of silica capillary. A pretreated silica capillary was reacted with 4‐(chloromethyl)phenyl isocyanate in the presence of dibutyltin dichloride as catalyst followed by sodium diethyl dithiocarbamate. Then a thin polymer layer was made on the inner surface of capillary by reversible addition‐fragmentation transfer polymerization of styrene, N‐phenylacrylamide, and methacrylic acid. A carefully adjusted formulation of reaction mixture and elaborated procedures were adopted to secure formation of the co‐polymer layer of enhanced separation performance. The co‐polymer immobilized open tubular capillary column was used for the separation of a synthetic mixture of five peptides and excellent separation efficiency (over 1.7 million per column) was obtained in the capillary electrochromatography mode. Such excellent separation efficiencies of ca. 1 m column have not been obtained in the isocratic elution mode so far. The column was also used for separation of the peptides in the liquid chromatography mode to show very good separation efficiency (average 286 700 per column).