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An unbreakable on-line approach towards sol-gel capillary microextraction

Bagheri, H ; Sharif University of Technology | 2011

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  1. Type of Document: Article
  2. DOI: 10.1016/j.chroma.2011.04.059
  3. Publisher: 2011
  4. Abstract:
  5. In this work a novel unbreakable sol-gel-based in-tube device for on-line solid phase microextraction (SPME) was developed. The inner surface of a copper tube, intended to be used as a high performance liquid chromatography (HPLC) loop, was electrodeposited by metallic Cu followed by the self assembled monolayers (SAM) of 3-(mercaptopropyl) trimethoxysilane (3MPTMOS). Then, poly (ethyleneglycol) (PEG) was chemically bonded to the -OH sites of the SAM already covering the inner surface of the copper loop using sol-gel technology. The homogeneity and the porous surface structure of the SAM and sol-gel coatings were examined using the scanning electron microscopy (SEM) and adsorption/desorption porosimetry (BET). The prepared loop was used for online in-tube SPME (capillary microextraction) of some selected polycyclic aromatic hydrocarbons (PAHs), as model compounds, from the aquatic media. After extraction, the HPLC mobile phase was used for on-line desorption and elution of the extracted analytes from the loop to the HPLC column. Major parameters affecting the extraction efficiency including the sample flow rate through the copper tube, loading time, desorption time and sample volume were optimized. For investigating the sorbent efficiency, four loops based on the copper tube itself, the copper tube after electrodeposition with Cu and the tubes with the SAMs and SAMs-sol-gel coating were made and compared. The SAMs-sol-gel coated loop clearly shows a prominently lead of at least 20-100 times of higher efficiency. The linearity for the analytes was in the range of 0.01-500μgL-1. Limit of detection (LOD) was in the range of 0.005-0.5μgL-1 and the RSD% values (n=5) were all below 8.3% at the 5μgL-1 level. The developed method was successfully applied to real water samples while the relative recovery percentages obtained for the spiked water samples were from 90 to 104%. The prepared loop exhibited long life time due to its remarkable solvent and mechanical stability. Different solvents such as methanol, acetonitrile and acetone were passed through the loop for many days and it was also used for more than 100 extractions/desorption of the selected analytes and no decrease in the peak areas was observed
  6. Keywords:
  7. Capillary microextraction (CME) ; High performance liquid chromatography-fluorescence detector (HPLC-FD) ; On-line approach ; In-tube solid phase microextraction ; Microextraction ; Self assembled monolayers (SAMs) ; Sol-gel technology ; Acetone ; Acetonitrile ; Chromatography ; Coatings ; Copper ; Desorption ; Efficiency ; Electrodeposition ; Fluorescence ; Gels ; High performance liquid chromatography ; Hydrocarbons ; Liquids ; Mechanical stability ; Methanol ; Organic solvents ; Polycyclic aromatic hydrocarbons ; Self assembled monolayers ; Sol-gel process ; Sol-gels ; Sols ; Surface structure ; Tubes (components) ; Extraction ; 3 (mercaptopropyl)trimethoxysilane ; Acenaphthene ; Acenaphthylene ; Anthracene ; Fluorene ; Macrogol ; Naphthalene ; Polycyclic aromatic hydrocarbon ; Self assembled monolayer ; Silane derivative ; Sulfur ; Unclassified drug ; Adsorption desorption porosimetry ; Analytic method ; Capillary microextraction ; Chemical bond ; Controlled study ; Flow rate ; High performance liquid chromatography ; Hydrolysis ; limit of detection ; Limit of quantitation ; Priority journal ; Process optimization ; Scanning electron microscopy ; Surface property ; Chromatography, High Pressure Liquid ; Linear Models ; Microscopy, Electron, Scanning ; Phase Transition ; Polycyclic Hydrocarbons, Aromatic ; Porosity ; Reproducibility of Results ; Sensitivity and Specificity ; Solid phase microextraction
  8. Source: Journal of Chromatography A ; Volume 1218, Issue 26 , 2011 , Pages 3952-3957 ; 00219673 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0021967311005693