Department of Chemistry, Seoul Women's University, 621 Hwarang-ro, Nowon-gu, Seoul 01797, Republic of Korea.
Molecules. 2023 Apr 17;28(8):3517. doi: 10.3390/molecules28083517.
Sample preparation is an essential process when handling complex matrices. Extraction without using a solvent requires the direct transfer of analytes from the sample to the adsorbent either in the gas or liquid phase. In this study, a wire coated with a new adsorbent was fabricated for in-needle microextraction (INME) as a solvent-free sample extraction method. The wire inserted into the needle was placed in the headspace (HS), which was saturated with volatile organic compounds from the sample in a vial. A new adsorbent was synthesized via electrochemical polymerization by mixing aniline with multi-walled carbon nanotubes (MWCNTs) in the presence of an ionic liquid (IL). The newly synthesized adsorbent using IL is expected to achieve high thermal stability, good solvation properties, and high extraction efficiency. The characteristics of the electrochemically synthesized surfaces coated with MWCNT-IL/polyaniline (PANI) adsorbents were characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and atomic force microscopy (AFM). Then, the proposed HS-INME-MWCNT-IL/PANI method was optimized and validated. Accuracy and precision were evaluated by analyzing replicates of a real sample containing phthalates, showing spike recovery between 61.13% and 108.21% and relative standard deviations lower than 15%. The limit of detection and limit of quantification of the proposed method were computed using the IUPAC definition as 15.8450.56 μg and 52.79168.5 μg, respectively. We concluded that HS-INME using a wire coated with the MWCNT-IL/PANI adsorbent could be repeatedly used up to 150 times without degrading its extraction performance in an aqueous solution; it constitutes an eco-friendly and cost-effective extraction method.
样品前处理是处理复杂基质时必不可少的环节。在不使用溶剂的情况下进行提取，需要将分析物直接从样品转移到吸附剂中，无论是在气相还是液相中。在这项研究中，制备了一种涂有线的新型吸附剂，用于针内微萃取（INME）作为无溶剂的样品提取方法。插入针中的线被放置在顶空（HS）中，顶空与小瓶中样品中的挥发性有机化合物饱和。通过在离子液体（IL）存在下混合苯胺和多壁碳纳米管（MWCNT）进行电化学聚合来合成新的吸附剂。预计使用 IL 的新合成吸附剂将实现高热稳定性、良好的溶解性能和高萃取效率。使用傅里叶变换红外（FTIR）光谱、扫描电子显微镜（SEM）、热重分析（TGA）和原子力显微镜（AFM）对涂有 MWCNT-IL/聚苯胺（PANI）吸附剂的电化学合成表面的特性进行了表征。然后，对所提出的 HS-INME-MWCNT-IL/PANI 方法进行了优化和验证。通过分析含有邻苯二甲酸酯的实际样品的重复样本来评估准确性和精密度，显示出回收率在 61.13%至 108.21%之间，相对标准偏差低于 15%。根据 IUPAC 定义，该方法的检出限和定量限分别计算为 15.8450.56μg 和 52.79168.5μg。我们得出结论，使用涂有 MWCNT-IL/PANI 吸附剂的线进行 HS-INME 可以在水溶液中重复使用 150 次而不会降低其萃取性能；它构成了一种环保且经济高效的萃取方法。
