Sae-Khow Ornthida, Mitra Somenath
Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, USA.
J Chromatogr A. 2009 Mar 20;1216(12):2270-4. doi: 10.1016/j.chroma.2009.01.037. Epub 2009 Jan 17.
In this research we report the implementation of micro-solid-phase extraction (mu-SPE) in the needle of a syringe for integrating sampling, analyte enrichment and sample introduction into a single device. Both single- and multi-walled carbon nanotubes (CNTs) were explored as high performance sorbents for mu-SPE in packed and self assembled formats. The need for such a sorbent was critical because the needle probe could hold only a small amount of material (around 300 microg). Conventional C-18 and self-assembled CNTs were found to be ineffective with enrichment factors less than one. However, packed beds of CNTs were found to be excellent sorbent phases, where high extraction efficiencies (as high as 27%) as well as enrichment factors (close to 7) could be achieved. The overall method showed excellent linearity, reproducibility, and low method detection limit (0.1-3 ng/mL for MWNTs). The sorption on CNTs followed Freundlich isotherms, and the functionalized CNTs were more effective for enriching the polar compounds.
在本研究中，我们报道了在注射器针头中实施微固相萃取（μ-SPE），以便将采样、分析物富集和样品引入集成到单个装置中。单壁和多壁碳纳米管（CNT）均被探索用作以填充和自组装形式用于μ-SPE的高性能吸附剂。对这种吸附剂的需求至关重要，因为针头探针只能容纳少量材料（约300微克）。发现传统的C-18和自组装碳纳米管无效，富集因子小于1。然而，发现碳纳米管填充床是优异的吸附相，可实现高萃取效率（高达27%）以及富集因子（接近7）。整体方法显示出优异的线性、重现性和低方法检测限（多壁碳纳米管为0.1 - 3纳克/毫升）。在碳纳米管上的吸附遵循弗伦德里希等温线，功能化碳纳米管对富集极性化合物更有效。
