Alhendal Abdullah, Almoaeen Randa Abd, Rashad Mohamed, Husain Ali, Mouffouk Fouzi, Ahmad Zahoor
Department of Chemistry, Kuwait University P. O. Box 5969, Safat 13060 Kuwait
RSC Adv. 2022 Jun 20;12(28):18077-18083. doi: 10.1039/d2ra02659g. eCollection 2022 Jun 14.
This work describes the preparation of an analytical microextraction sorbent using a simple and versatile sol-gel hybrid composite, , aramid oligomers wrapping multi-walled carbon nanotubes (CNTs) covalently bonded to a porous silica network. To overcome the inherent shortcomings of the CNTs' solubility and dispersion in both organic phases and in the sol-gel solution, the outer surface of the CNTs was initially functionalized with carboxylic acid groups and then reacted with both aramid oligomers and 3-aminopropyl triethoxysilane (APTES). The obtained sorbent was characterized by FT-IR, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Using sol-gel chemistry, the functionalized CNTs were coated onto SPME fibers and used in conjunction with GC-MS for the analysis of polycyclic aromatic hydrocarbons (PAHs) in water and soil samples. Excellent repeatability (run-to-run RSD% ∼ 8) and reproducibility (fiber-to-fiber RSD% ∼ 6) were achieved in addition to low LODs (0.10-0.30 ng mL) and noticeable recovery%. The present method of sorbent preparation led to enhanced thermal and chemical stabilities, a long sorbent lifetime and good affinity towards PAHs. Moreover, the present sorbent enhanced the extraction capability by more than 30% compared to that of commercially available PDMS counterparts.
这项工作描述了一种分析微萃取吸附剂的制备方法，该吸附剂采用一种简单且通用的溶胶 - 凝胶杂化复合材料，即芳纶低聚物包裹的多壁碳纳米管（CNTs）共价键合到多孔二氧化硅网络上。为了克服碳纳米管在有机相和溶胶 - 凝胶溶液中的溶解性和分散性方面的固有缺点，首先用羧酸基团对碳纳米管的外表面进行功能化，然后使其与芳纶低聚物和3 - 氨丙基三乙氧基硅烷（APTES）反应。通过傅里叶变换红外光谱（FT - IR）、扫描电子显微镜（SEM）和热重分析（TGA）对所得吸附剂进行了表征。利用溶胶 - 凝胶化学方法，将功能化的碳纳米管涂覆在固相微萃取（SPME）纤维上，并与气相色谱 - 质谱联用（GC - MS）用于分析水和土壤样品中的多环芳烃（PAHs）。除了低检测限（0.10 - 0.30 ng/mL）和可观的回收率外，还实现了出色的重复性（运行间相对标准偏差百分比约为8）和重现性（纤维间相对标准偏差百分比约为6）。本吸附剂制备方法提高了热稳定性和化学稳定性，延长了吸附剂寿命，并对多环芳烃具有良好的亲和力。此外，与市售的聚二甲基硅氧烷（PDMS）同类产品相比，本吸附剂的萃取能力提高了30%以上。
