Shende Chetan, Kabir Abuzar, Townsend Eric, Malik Abdul
Department of Chemistry, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida 33620-5250, USA.
Anal Chem. 2003 Jul 15;75(14):3518-30. doi: 10.1021/ac0207224.
A sol-gel chemistry-based method was developed for the preparation of highly stable capillary gas chromatography (GC) columns with surface-bonded poly(ethylene glycol) (PEG) stationary phase. Through a single-step procedure, it concurrently provided column deactivation, stationary-phase coating, and chemical immobilization of the coated film. Sol-gel reactions were carried out within fused-silica capillaries that were filled with properly designed sol solutions containing two sol-gel precursors, two different triethoxysilyl-derivatized poly(ethylene glycol)s, two sol-gel catalysts, and a deactivation reagent. Hydrolytic polycondensation reactions led to the formation of a sol-gel coating chemically bonded to the inner walls of the capillary. A number of sol-gel coated fused-silica capillary columns were prepared using sol-gel-active PEG derivatives. These columns demonstrated many inherent advantages, the main being the strong anchoring of the coating to the capillary wall resulting from chemical bonding with the silanol groups on the fused-silica capillary inner surface. This chemical bonding yielded strongly immobilized PEG coatings with outstanding thermal stability (up to 320 degrees C). To our knowledge, such a high thermal stability has not been achieved so far on conventionally prepared PEG GC columns. Sol-gel PEG columns provided excellent chromatographic performances: high number of theoretical plates, excellent run-to-run and column-to-column reproducibility, and pronounced selectivity for a wide range of test solutes. Using n-octadecane as a test solute (k = 7.14), an efficiency value of 3200 theoretical plates/m was obtained on a 10 m x 0.25 mm i.d. fused-silica capillary column. Five sol-gel PEG columns provided RSD values of 1.09% for column efficiency (solute, n-octadecane), 1.37% for retention factor (solute, n-octadecane), and 0.9% for separation factor (for solute pair o- and p-xylene). In five replicate measurements using the same column, RSD values of less than 0.50% for the retention time and 1.36% for retention factor (k) were obtained.
开发了一种基于溶胶-凝胶化学的方法，用于制备具有表面键合聚乙二醇（PEG）固定相的高度稳定的毛细管气相色谱（GC）柱。通过一步法，它同时实现了柱去活、固定相涂覆以及涂覆膜的化学固定。溶胶-凝胶反应在填充有精心设计的溶胶溶液的熔融石英毛细管内进行，该溶胶溶液包含两种溶胶-凝胶前驱体、两种不同的三乙氧基硅烷基衍生化聚乙二醇、两种溶胶-凝胶催化剂和一种去活试剂。水解缩聚反应导致在毛细管内壁形成化学键合的溶胶-凝胶涂层。使用具有溶胶-凝胶活性的PEG衍生物制备了许多溶胶-凝胶涂覆的熔融石英毛细管柱。这些柱显示出许多固有优势，主要优势在于涂层通过与熔融石英毛细管内表面的硅醇基团化学键合而牢固地锚定在毛细管壁上。这种化学键合产生了具有出色热稳定性（高达320℃）的牢固固定的PEG涂层。据我们所知，在传统制备的PEG GC柱上至今尚未达到如此高的热稳定性。溶胶-凝胶PEG柱提供了出色的色谱性能：理论塔板数高、运行间和柱间重现性优异，以及对多种测试溶质具有明显的选择性。使用正十八烷作为测试溶质（k = 7.14），在一根10 m×0.25 mm内径的熔融石英毛细管柱上获得了3200理论塔板数/米的效率值。五根溶胶-凝胶PEG柱的柱效率（溶质为正十八烷）的相对标准偏差（RSD）值为1.09%，保留因子（溶质为正十八烷）的RSD值为1.37%，分离因子（溶质对为邻二甲苯和对二甲苯）的RSD值为0.9%。在使用同一根柱的五次重复测量中，保留时间的RSD值小于0.50%，保留因子（k）的RSD值为1.36%。
