高惰性、低流失、高效石英毛细管色谱柱的研制及有机氯农药残留量的分析

通过过在三种不同脱活试剂中加入二丁基二月桂酸锡催化剂对石英石细管柱进行预脱活处理，屏蔽石英毛细管内表面的活性点，改善石英毛细管柱内表面与固定相的润湿性，提高色谱柱的柱效和耐温性，降低柱流失，从而制备出高质量的石英毛细管色谱柱，同时考察了不同固定相与不同脱活层的润湿性，对中药材和食品中有机氯农药残留量进行了分析，得到了满意的效果。     

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。     

用气-质联用技术检测葱、蒜、韭菜中多种农药残留量时试样预处理方法

采用气相色谱及质谱联用技术，测定葱、蒜及韭菜等蔬菜中多种农药残留量时，在粉碎试样之前，用磷酸或微波加热处理试样，可使蒜酶钝化并消除其基体干扰。试验结果显示，或用磷酸处理，或经微波加热处理，均能有效消除高背景的干扰。试样在粉碎前经磷酸预处理，在所测定的75种农药中有90％以上农药的回收率达到70％～120％之间。     

C4馏分中微量乙腈的大口径毛细管色谱测定

采用水相萃取富集技术，利用大口径厚液膜HLZ－60石英毛细管色变柱对C4烃抽余液中的微量乙腈进行分析；结果表明LZP－60石英毛细管色谱柱对乙腈化合物具有良好的惰性和色谱选择性；残余烃杂质峰和大量水分不干扰乙腈峰的流出；定量分析结果表明，样品测量的相对标准偏差为15％，其相对误差为7％，色谱分离检测法完全满足实际工作中微量乙腈分析的需要。     

毛细管气相色谱法分析蜂王浆制剂中的10-羟基癸烯-2酸

本文介绍了一种用毛细管气相色谱定性定量测定蜂王浆制剂中10-HDA含量的方法。样品经预处理后,提取物同硅烷化试剂BSTFA进行衍生化反应,反应产物经由交联SE-30石英毛细管柱分离。该法衍生化反应简单、快速、分离完全,可用于分析蜂王浆及其它蜂王浆制剂。     

3种全烷基化β—环糊精作毛细管气相色谱固定相的研究

作者合成了３种全烷基化β－环糊精，并将其涂溃石英毛细管色谱柱分离位置异构体和光学异构体得了良好的结果，其中全甲基化β－环糊精具有最好的选择性。     

毛细管气相色谱,色谱—质谱联用测定金刚烷及其异构体

本文给出了金刚烷及其异构体合物系毛细管气相色谱及色谱－质谱联用分析方法，色谱柱为ＣＢＰＩ键合石英毛细管、氢火焰检则器。列出了标准曲线和检测条件，回收率为９８．３％－１０１．２％，相对标准偏差〈４．０％，本方法定量分析快速、简便、准确。     

有机溶剂对某些有机磷农药的MECC洗提影响的研究

以有机磷农药甲基对硫磷、对硫磷等为被试验物质，探讨了在十二烷基硫酸钠、硼砂电解液中加入甲醇、乙醇、异丙醇、乙腈等有机溶剂对某些有机磷农药的毛细管胶束电动色谱分离的影响。并从电解液的物理化学性质和毛细管色谱动力学两方面阐明了其影响机理     

毛细管胶束电动色谱法检测4种有机磷农药

用毛细管胶束电动色谱电化学检测的方法对对氧磷、甲基对硫磷、乙基对硫磷、扑灭松等4种常见有机磷农药进行分离检测。使用30 cm×20μm i.d.的石英毛细管,当分离电压为12 kV,工作电极电势为-0.6V,在pH值为5.0的20 mmol/L乙酸-乙酸钠缓冲液与20 mmol/L十二烷基硫酸钠溶液中,对氧磷、甲基对硫磷、乙基对硫磷、扑灭松4种组分在11 m in内得到基线分离,检出限分别为0.086、0.64、0.67、3.4 pg。将该方法用于地表水样品的检测,加标回收率为94%~102%。     

Practical aspects of the temperature dependence of the activity of uncoated and coated fused-silica columns in gas chromatography

Summary Uncoated fused-silica capillary tubing has found widespread use in GC and GC/MS, e. g., in splitless and oncolumn injection, in the open-split interface used in GC/MS, and in hybrid fused-silica/glass capillary columns. As the uncoated capillary is usually more active than the coated one, it is very important to pay sufficient attention to the deactivation of the uncoated capillary. Otherwise the uncoated portion used as column inlet and/or outlet may become the main source of column activity and of analytical error. This case is especially serious under temperature-programmed runs. The effect of film thickness and temperature program on column activity is also discussed.     

High-performance liquid chromatographic enantioseparations on capillary columns containing crosslinked polysaccharide phenylcarbamate derivatives attached to monolithic silica

Monolithic capillary columns containing native silica gel were covalently modified with 3,5-disubstituted phenylcarbamate derivatives of cellulose and amylose and applied for enantioseparations in capillary LC. The method previously used for covalent immobilization of polysaccharide phenylcarbamate derivatives onto the surface of microparticulate silica gel was successfully adapted for in situ modification of monolithic fused-silica capillary columns. The effects of the nature of polysaccharide and the substituents, as well as of multiple covalent immobilization of polysaccharide derivative on chromatographic performance of capillary columns were studied. The capillary columns obtained using this technique are stable in all solvents commonly used in LC and exhibit promising enantiomer resolving ability.     

Evaluation of fused-silica capillary columns for GC/ECD analysis of chlorinated hydrocarbons listed in EPA method 8120

Four mega-bore, one wide-bore, and one narrow-bore fused-silica capillary columns were evaluated for their applicability to the GC/ECD analysis of 22 chlorinated hydrocarbons, some of which are currently targeted by EPA Method 8120. No one column can resolve all 22 compounds investigated here. Four compounds (two pairs) are coeluting on the SPB-35, DB-210, DB-WAX, and DB-519 fused-silica capillary columns, five compounds (two groups) are coeluting on the DB-1301 fused-silica capillary column, and ten compounds (five pairs) are coeluting on the SPB-5 fused-silica capillary column. The analysis time varies between 30 and 50 min. The order of elution of the chlorinated benzenes seems to depend on their boiling points rather than on the polarity of the liquid phase. The retention times of an additional nine chlorinated toluenes, eight chlorinated xylenes, and five chlorinated naphthalenes are also reported. Electron capture detector linearity is reported for the DB-210 fused-silica capillary column. Five brominated compounds were investigated as possible internal standards for Method 8120.     

Fast headspace analysis with short microcapillary columns

Summary A new method of analysis using headspace gas chromatography with microcapillary columns is proposed. Small diameter (50 μm I.D.) fused-silica capillary columns with non-extractable SE-54 and PS-255 polysiloxane stationary phases were used for the analysis of low boiling organic compounds. The small diameter columns possess the usual very high efficiency so that the method can be employed for the headspace analysis of complex mixtures. The use of short microcolumns reduces the analysis times in comparison to conventional capillary columns. Good performances were obtained in the analysis of volatile compounds in some lemon essential oil, perfumes, and water samples.     

Factors affecting the capillary electrophoresis of ricin, a toxic glycoprotein

Conditions for the analysis of ricin with capillary electrophoresis were investigated. Uncoated and coated columns were tested with a variety of different buffer combinations which included different principal components, pH, ionic strength, and additives. Of the combinations tested, uncoated columns used with either zwitterionic salts or putrescine gave the best results. Multiple peaks were resolved with these conditions. Coated columns generally yielded between 1000 and 5000 plates with several buffer combinations. Ricin may be analyzed faster and with greater resolution with capillary electrophoresis employing untreated fused-silica columns than by using other chromatographic techniques.     

Repartition effect of aromatic polyaniline coatings on the separation of bioactive peptides in capillary electrophoresis

The capillary walls of fused-silica capillary electrophoresis (CE) columns were modified with a thin film of polyaniline (PANI), providing open-tubular columns with a stable coating containing aromatic groups and amine functionalities. Fast and efficient separations were observed for small bioactive peptides under acidic conditions on PANI-coated columns. The mechanism of separation is based on hydrophobic interactions between the analytes and the polymeric matrix. Good reproducibility was observed from run-to-run. Due to the simple derivatization procedure, method flexibility, the uniformity of the coating and its stability, conjugated polymers could find practical application in capillary zone electrophoresis (CZE) separations.     

超支化聚醚涂层毛细管柱在线推扫富集检测6种有机磷农药

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。     

Preparation of thermally stable phenylpolysiloxane fused silica capillary columns. Optimization and evaluation of the deactivation by capillary GC and solid state 29Si NMR

The deactivation of fused silica capillary columns with a laboratory-made poly-diphenylvinylmethylhydrosiloxane copolymer has been investigated. The deactivation obtained at different temperatures and reaction times is characterized with a dual column capillary GC system [1]. In parallel, the effect of the silylation temperatures and reaction times on the nature, the structure, and the chemical properties of the deactivation layer has also been studied by solid-state ²⁹Si NMR spoctroscopy. A fumed silica, Cab-O-Sil M5, was used as a model substrate for these spectroscopic studies. The deactivated fused silica capillaries show an excellent thermal stability (up to 400°C), a high resistance to solvolysis, and a minimal interaction to various critical test components. A good wettability of the fused silica capillary columns deactivated with this reagent was confirmed by successful subsequent coating with polysiloxanes with different phenyl contents.     

Behavior of n-alkanes on poly(oxyethylene) capillary columns. Evaluation of interfacial effects

The solvation behavior of n-alkanes on poly(oxyethylene) was studied employing capillary gas chromatography. Interfacial effects were discriminated and evaluated through the analysis of retention data from six commercial fused-silica capillary columns, having film thicknesses of 0.15-5 microm. Expressions for the mixed retention mechanism in capillary columns were deduced from assumptions of a general character. Partition coefficients were determined for the n-alkanes up to 28 carbon atoms, at temperatures ranging from 40 to 240 degrees C. In agreement with other authors, it was observed that interfacial phenomena contribute poorly to the chromatographic retention, being negligible over 140 degrees C for homologues with less than 16 carbons.     

External polyacrylate-coating as alternative material for preparation of photopolymerized sol-gel monolithic column

Photopolymerized sol-gel monolithic columns for use in capillary electrochromatography were prepared in 125 microm i.d. polyacrylate-coated fused-silica capillaries. The polyacrylate-coating, unlike the polyimide one, is transparent to the radiation used (approximately 370 nm), and thus, no coating removal is necessary. This is a very important particularity since intrinsic capillary column characteristics, such as flexibility and mechanical resistance, are unchanged. A mixture containing metacryloxypropyltrimethoxysilane (MPTMS) as the polymeric precursor, hydrochloric acid as the catalyst, toluene as the porogen and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Irgacure 819) as the photoinitiator was irradiated at 370 nm for 20 min inside the capillaries to prepare the columns through sol-gel approach. The versatility and viability of the use of polyacrilate as a new capillary external coating were shown through preparation of two columns under different conditions, which were tested in electrochromatography for separation of standard mixture containing thiourea (marker compound), propylbenzene, phenanthrene and pyrene.