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chromatography--gel
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Sol-gel-based SPME and GC-MS for trace determination of geosmin in water and apple juice samples
, Article Chromatographia ; Volume 66, Issue 9-10 , 2007 , Pages 779-783 ; 00095893 (ISSN) ; Aghakhani, A ; EsHaghi, A ; Sharif University of Technology
2007
Abstract
A headspace solid-phase microextraction (HS-SPME) method was developed for the trace determination of geosmin in water and apple juice samples. A poly(dimethylsiloxane) (PDMS) fiber was synthesized as coated fiber using sol-gel methodology. After performing the extraction in the headspace, the fiber was introduced directly into the injection port of a gas chromatography-mass spectrometry (GC-MS) using electron impact (EI) ionization mode. One-at-the-time optimization strategy was applied to investigate and optimize important extraction parameters such as extraction temperature and time, ionic strength, headspace volume, and desorption temperature and time. The analytical data exhibited an...
Design and Synthesis of Novel Polyglycerol Hybrid Nanomaterials for Potential Applications in Drug Delivery Systems
, Article Macromolecular Bioscience ; Volume 11, Issue 3 , NOV , 2011 , Pages 383-390 ; 16165187 (ISSN) ; Adeli, M ; Vossoughi, M ; Shokrgozar, M. A ; Sharif University of Technology
2011
Abstract
The synthesis of a new drug delivery system based on hybrid nanomaterials containing a β-CD core and hyperbranched PG is described. Conjugating PG branches onto β-CD not only increases its water solubility but also affects its host/guest properties deeply. It can form molecular inclusion complexes with small hydrophobic guest molecules such as ferrocene or FITC with reasonable release. In addition, the achievable payloads are significantly higher as for carriers such as hyperbranched PGs. Short-term in vitro cytotoxicity and hemocompatibility tests on L929 cell lines show that the hybrid nanomaterial is highly biocompatible. Due to their outstanding properties, β-CD-g-PG hybrid nanomaterials...
Novel unbreakable solid-phase microextraction fiber by electrodeposition of silica sol-gel on gold
, Article Journal of Separation Science ; Volume 34, Issue 22 , 2011 , Pages 3246-3252 ; 16159306 (ISSN) ; Sistani, H ; Ayazi, Z ; Sharif University of Technology
Abstract
A new technique for preparation of an unbreakable solid-phase microextraction (SPME) fiber, using sol-gel technology is developed. Primarily, an ultrathin two-dimensional intermediate film was prepared by hydrolysis of 3-(trimethoxysilyl)-1-propanthiol self-assembled monolayer grafted onto gold, then a stationary phase by electrodeposition of 3-(trimethoxysilyl) propylmethacrylate as a precursor, tetramethyl orthosilicate and polyethylene glycol as a coating polymer was produced. The scanning electron microscopy images revealed that the new fiber exhibits a rather porous and homogenous surface. The thermal stability of the fabricated fiber was investigated by thermogravimetric analysis. The...
A novel needle trap sorbent based on carbon nanotube-sol-gel for microextraction of polycyclic aromatic hydrocarbons from aquatic media
, Article Analytica Chimica Acta ; Volume 683, Issue 2 , January , 2011 , Pages 212-220 ; 00032670 (ISSN) ; Ayazi, Z ; Aghakhani, A ; Sharif University of Technology
2011
Abstract
A new type of composite material based on carbon nanotubes (CNTs) and sol-gel chemistry was prepared and used as sorbent for needle trap device (NTD). The synthesized composite was prepared in a way to disperse CNTs molecules in a sol-gel polymeric network. CNT/silica composites with different CNT doping levels were successfully prepared, and the extraction capability of each composite was evaluated. Effects of surfactant and the oxidation duration of CNTs on the extraction efficiency of synthesized composites were also investigated. The applicability of the synthesized sorbent was examined by developing a method based on needle trap extraction (NTE) and gas chromatography mass spectrometry...