Kulkarni Sameer, Shearrow Anne M, Malik Abdul
Department of Chemistry, University of South Florida, 4202 E. Fowler Avenue, CHE 205, Tampa, FL 33620-5250, USA.
J Chromatogr A. 2007 Dec 7;1174(1-2):50-62. doi: 10.1016/j.chroma.2007.10.082. Epub 2007 Nov 1.
Sol-gel coating with covalently bonded low-molecular-weight (MW<300 Da) poly(ethylene glycol) (PEG) chains was developed for capillary microextraction (CME). The sol-gel chemistry proved effective in the immobilization of low-molecular-weight PEGs thanks to the formation of chemical bonds between the organic-inorganic hybrid sol-gel PEG coating and the fused silica capillary inner surface. This chemical anchorage provided excellent thermal and solvent stability to the created sol-gel PEG coating as is evidenced by its high upper limit of allowable conditioning temperature (340 degrees C) and its practically identical performance before and after rinsing with various solvents. The prepared sol-gel PEG coating provided simultaneous extraction of moderately polar and highly polar analytes from aqueous samples without requiring derivatization, pH adjustment or salting-out procedures. Detection limits on the order of nanogram per liter (ng/L) were achieved in CME-GC-flame ionization detection experiments designed for the preconcentration and trace analysis of both highly polar and moderately polar compounds extracted directly from aqueous media using sol-gel short-chain PEG coated microextraction capillaries.
为毛细管微萃取（CME）开发了一种具有共价键合的低分子量（MW<300 Da）聚乙二醇（PEG）链的溶胶-凝胶涂层。由于有机-无机杂化溶胶-凝胶PEG涂层与熔融石英毛细管内表面之间形成了化学键，溶胶-凝胶化学方法在固定低分子量PEG方面被证明是有效的。这种化学固定为所制备的溶胶-凝胶PEG涂层提供了出色的热稳定性和溶剂稳定性，这一点从其较高的允许老化温度上限（340摄氏度）以及用各种溶剂冲洗前后几乎相同的性能中得到了证明。所制备的溶胶-凝胶PEG涂层无需衍生化、调节pH值或盐析程序，即可同时从水性样品中萃取中等极性和高极性分析物。在使用溶胶-凝胶短链PEG涂层微萃取毛细管直接从水性介质中萃取高极性和中等极性化合物进行预浓缩和痕量分析的CME-GC-火焰离子化检测实验中，实现了纳克每升（ng/L）级别的检测限。
