Sol−Gel Germania Triblock Polymer Coatings of Exceptional pH Stability in Capillary Microextraction Online-Coupled to High-Performance Liquid Chromatography

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• 作者：Scott S. Segro ; Judy Triplett ; Abdul Malik
• 刊名：Analytical Chemistry
• 出版年：2010
• 出版时间：May 15, 2010
• 年：2010
• 卷：82
• 期：10
• 页码：4107-4113
• 全文大小：246K
• 年卷期：v.82,no.10(May 15, 2010)
• ISSN：1520-6882

文摘

For the first time, a germania-based sol−gel coating was used in capillary microextraction (CME) in combination with high-performance liquid chromatography (HPLC). A hydroxy-terminated triblock copolymer, poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide), was covalently bonded into a sol−gel germania matrix in the course of its creation from an alkoxide precursor via hydrolytic polycondensation reactions. A thin layer of this in situ-created sol−gel hybrid material was covalently anchored to the inner walls of a 0.25 mm i.d. fused silica capillary to produce a sol−gel germania triblock polymeric sorbent in the form of a highly stable surface coating. Such a coating served as an effective extracting phase for the preconcentration of a wide range of polar and nonpolar analytes (e.g., alcohols, amines, ketones, phenols, and polycyclic aromatic hydrocarbons) with nanomolar and picomolar detection limits. Most significantly, the sol−gel germania triblock polymer coating demonstrated impressive resistance to extreme pH conditions, surviving 5 days of continuous exposure to 1.0 M HCl (pH ≈ 0.0) or 1.0 M NaOH (pH ≈ 14.0), practically without any changes in performance. This shows the suitability of sol−gel germania hybrid organic−inorganic hybrid materials for use as sorbents or stationary phases under extreme pH conditions, often needed in a variety of separation and sample preparation techniques and applications, including ion chromatography, hydrophobic interaction chromatography, proteomics, HPLC with electrochemical detection, isoelectric focusing, and extraction of acidic and basic analytes.