Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran.
Mikrochim Acta. 2020 Apr 2;187(4):256. doi: 10.1007/s00604-020-4224-9.
Schiff base network-1 (SNW-1), as a new generation of covalent organic frameworks (COFs), was synthesized and modified by fabrication of a composite with graphene oxide (GO). The fabricated nanocomposite was characterized with FT-IR spectroscopy, XRD, FE-SEM, EDX, TGA, and the nitrogen adsorption-desorption technique. Characterization results showed that SNW-1 can reduce GO during the fabrication procedure and produce an effective and stable nanocomposite. This nanocomposite was deposited on the surface of a stainless steel wire via a single phase inversion method with the help of polyethersulfone, as a porous adhesive material. This robust and stable coating was used for head space solid-phase microextraction of phthalate esters (PhEs) from water samples. Determination of the PhEs was performed with gas chromatography coupled to mass spectrometry. SNW-1 is N-rich, and reduced-GO is full of hexagonal conjugated rings. Therefore, due to hydrogen binding and π-interaction, the coating has a high tendency to PhEs. Effective adsorption and desorption parameters were optimized. The performance of the method was evaluated in terms of linear ranges (LRs from 0.05 to 100 μg L with R ≥ 0.9942) and limits of detection (LODs in the range of 0.01-0.50 μg L). The average repeatability and fiber-to-fiber reproducibility were 6.8% and 9.2%, respectively. The method was employed to trace determination of PhEs in drinking water and pickled cucumber solution with good recovery (80.5-111.0%) and reliable reproducibility (5.5-9.5%). Graphical abstract Schematic representation of headspace-solid phase microextraction (HS-SPME) of phthalate esters (PhEs) from pickled cucumber solution and determination with gas chromatography-mass spectrometry (GC-MS).
席夫碱网络-1（SNW-1）作为新一代共价有机骨架（COFs），通过与氧化石墨烯（GO）复合进行合成和修饰。所制备的纳米复合材料采用傅里叶变换红外光谱（FT-IR）、X 射线衍射（XRD）、场发射扫描电子显微镜（FE-SEM）、能谱分析（EDX）、热重分析（TGA）和氮气吸附-脱附技术进行了表征。表征结果表明，SNW-1 在制备过程中可以还原 GO，产生有效且稳定的纳米复合材料。该纳米复合材料在聚醚砜的帮助下通过单相相转化法沉积在不锈钢丝表面，作为多孔粘结材料。这种坚固且稳定的涂层用于通过顶空固相微萃取（HS-SPME）从水样中萃取邻苯二甲酸酯（PhE）。PhE 的测定采用气相色谱-质谱联用（GC-MS）进行。SNW-1 是富氮的，还原的 GO 充满了六元共轭环。因此，由于氢键和π 相互作用，涂层对 PhE 具有很高的吸附倾向。优化了有效的吸附和解吸参数。该方法的性能通过线性范围（LR，从 0.05 到 100μg L，相关系数 R≥0.9942）和检测限（LOD，在 0.01-0.50μg L 范围内）进行了评估。方法的重复性和纤维间重现性分别为 6.8%和 9.2%。该方法用于检测饮用水和腌制黄瓜溶液中的 PhE，回收率良好（80.5-111.0%），重现性可靠（5.5-9.5%）。
