Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, Tehran, Iran.
Anal Chim Acta. 2012 Feb 24;716:34-9. doi: 10.1016/j.aca.2011.03.016. Epub 2011 Mar 12.
A novel solid phase microextraction (SPME) fiber was fabricated by electrospinning method in which a polymeric solution was converted to nanofibers using high voltages. A thin stainless steel wire was coated by the network of polymeric nanofibers. The polymeric nanofiber coating on the wire was mechanically stable due to the fine and continuous nanofibers formation around the wire with a three dimensional structure. Polyamide (nylon 6), due to its suitable characteristics was used to prepare the unbreakable SPME nanofiber. The scanning electron microscopy (SEM) images of this new coating showed a diameter range of 100-200 nm for polyamide nanofibers with a homogeneous and porous surface structure. The extraction efficiency of new coating was investigated for headspace solid-phase microextraction (HS-SPME) of some environmentally important chlorophenols from aqueous samples followed by gas chromatography-mass spectrometry (GC-MS) analysis. Effect of different parameters influencing the extraction efficiency including extraction temperature, extraction time, ionic strength and polyamide amount were investigated and optimized. In order to improve the chromatographic behavior of phenolic compounds, all the analytes were derivatized prior to the extraction process using basic acetic anhydride. The detection limits of the method under optimized conditions were in the range of 2-10 ng L(-1). The relative standard deviations (RSD) (n=3) at the concentration level of 1.7-6.7 ng mL(-1) were obtained between 1 and 7.4%. The calibration curves of chlorophenols showed linearity in the range of 27-1330 ng L(-1) for phenol and monochlorophenols and 7-1000 ng L(-1) for dichloro and trichlorophenols. Also, the proposed method was successfully applied to the extraction of phenol and chlorophenols from real water samples and relative recoveries were between 84 and 98% for all the selected analytes except for 2,4,6 tricholophenol which was between 72 and 74%.
一种新型固相微萃取（SPME）纤维是通过静电纺丝法制备的，其中聚合物溶液在高压下转化为纳米纤维。一根细的不锈钢丝被聚合物纳米纤维网络包裹。由于在钢丝周围形成了具有三维结构的细而连续的纳米纤维，因此涂覆在钢丝上的聚合物纳米纤维涂层具有机械稳定性。聚酰胺（尼龙 6）因其合适的特性而被用于制备不易损坏的 SPME 纳米纤维。这种新涂层的扫描电子显微镜（SEM）图像显示，聚酰胺纳米纤维的直径范围为 100-200nm，具有均匀且多孔的表面结构。采用顶空固相微萃取（HS-SPME）-气相色谱-质谱（GC-MS）联用技术，研究了新型涂层对环境中重要氯苯酚的萃取效率。考察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、离子强度和聚酰胺用量。为了改善酚类化合物的色谱行为，在萃取前，所有分析物均先用碱性乙酸酐衍生化。在优化条件下，该方法的检测限在 2-10ng L（-1）范围内。在 1.7-6.7ng mL（-1）浓度水平下，获得了相对标准偏差（RSD）（n=3）在 1-7.4%之间。氯苯酚的校准曲线在酚和单氯苯酚的 27-1330ng L（-1）范围内和二氯和三氯苯酚的 7-1000ng L（-1）范围内呈线性。此外，该方法还成功应用于实际水样中苯酚和氯苯酚的提取，除 2,4,6-三氯苯酚的回收率在 72-74%之间外，所有选定分析物的回收率均在 84-98%之间。
