Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, P.O. Box 11365-9516, Tehran, Iran.
Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, P.O. Box 11365-9516, Tehran, Iran.
J Chromatogr A. 2014 Jan 10;1324:11-20. doi: 10.1016/j.chroma.2013.11.024. Epub 2013 Nov 17.
In the present work, a new solid phase microextraction (SPME) fiber coating based on modified silica-polyamide (PA) nanocomposite was electrospun on a stainless steel wire. Four modified silica-PA nanocomposites together with PA were fabricated by dispersing several typical modified silica nanoparticles in PA polymer solution prior to electrospinning. The surface characteristic of PA nanofibers and modified silica-PA nanocomposites was investigated using scanning electron microscopy (SEM). The homogeneity and the porous surface structure of the modified silica-PA nanocomposites were confirmed by SEM, showing nanofibers diameters lower than 170 nm. The applicability of the new fiber coating was examined by headspace SPME of some selected chlorobenzenes (CBs), as model compounds, from aqueous samples. Subsequently, the extracted analytes were transferred into a gas chromatography (GC) by thermal desorption. Influencing parameters on the morphology of nanocomposites such as type of modified silica nanoparticles and the weight ratio of components were optimized. In addition, effects of different parameters influencing the extraction efficiency including extraction temperature, extraction time, ionic strength, desorption temperature, and desorption time were investigated and optimized. Eventually, the developed method was validated by gas chromatography-mass spectrometry (GC-MS). At the optimum conditions, the relative standard deviation values for a double distilled water spiked with the selected CBs at 100 ng L(-1) were 4-12% (n=3) and the limit of detection for the studied compounds was between 5 and 30 ng L(-1). The calibration curves of analytes were investigated in the range of 50-1000 ng L(-1) and correlation coefficients (R(2)) between 0.9897 and 0.9992 were obtained.
在本工作中，一种新型固相微萃取（SPME）纤维涂层基于改性的硅-聚酰胺（PA）纳米复合材料，通过在不锈钢丝上静电纺丝而制备。通过在 PA 聚合物溶液中分散几种典型的改性二氧化硅纳米粒子，制备了四种改性的硅-PA 纳米复合材料与 PA。使用扫描电子显微镜（SEM）研究了 PA 纳米纤维和改性的硅-PA 纳米复合材料的表面特性。通过 SEM 证实了改性的硅-PA 纳米复合材料的均匀性和多孔表面结构，显示出低于 170nm 的纳米纤维直径。通过顶空 SPME 从水样中萃取一些选定的氯苯（CBs）作为模型化合物，来检查新纤维涂层的适用性。随后，通过热解吸将提取的分析物转移到气相色谱仪（GC）中。优化了影响纳米复合材料形态的因素，如改性二氧化硅纳米粒子的类型和组分的重量比。此外，还研究并优化了影响萃取效率的不同参数，包括萃取温度、萃取时间、离子强度、解吸温度和解吸时间。最终，通过气相色谱-质谱联用（GC-MS）对开发的方法进行了验证。在最佳条件下，用 100ngL(-1) 的所选 CBs 双蒸水加标时，相对标准偏差值为 4-12%（n=3），研究化合物的检出限在 5-30ngL(-1) 之间。在 50-1000ngL(-1) 的范围内研究了分析物的校准曲线，获得了 0.9897 到 0.9992 之间的相关系数（R(2)）。
