尼龙6纳米纤维膜富集/固相表面荧光法快速检测水体痕量多环芳烃研究

以静电纺丝法自制的尼龙6纳米纤维膜为吸附材料,建立了快速测定水体痕量多环芳烃(PAHs)的固相表面荧光光谱法(SSF)。将直径为5 cm的尼龙6纳米纤维膜作为滤膜用于抽滤菲、芘、荧蒽的水溶液,将膜自然晾干后置于可变角粉末样品池上,利用荧光分光光度计测量膜表面PAHs的三维固相表面荧光光谱特征,确定最佳激发发射波长,考察荧光强度随溶液初始质量浓度的线性变化关系。结果表明,菲、芘、荧蒽的最大激发发射荧光中心分别位于Ex/Em=255nm/368 nm、Ex/Em=340 nm/376 nm和Ex/Em=290 nm/437 nm处。当抽滤水样体积为500 m L时,菲、芘、荧蒽荧光强度与初始质量浓度之间的标准曲线分别为y=9432.4x+261.1,线性范围为5~500ng/m L;y=753480x+805.51,线性范围为0.2~10 ng/m L;y=9946.06x+603.48,线性范围为10~400 ng/m L,检出限分别为0.973 ng/m L、0.016 2 ng/m L和0.089 6 ng/m L。当质量浓度分别为100 ng/m L、10ng/m L和50 ng/m L时,7次测量的相对标准偏差(RSD)分别为7.1%、2.6%和5.1%,平均值相对误差分别为1%、2%和-0.2%。自来水低中高3个质量浓度的平均加标回收率分别为87.2%~98.2%、101%~120%、85.8%~92.3%。本方法具有简便、经济、灵敏度高等优点,适合于水体痕量PAHs的快速测定。

Quick identification and determination of the trace polycyclic aromatic hydrocarbons in water via nylon 6 nanofiber membrane enrichment solid-phase surface fluorescence

This paper takes it as its goal to present a quick identification and determination method of the trace polycyclic aromatic hydrocarbons in the water via nylon 6 nanofiber membrane enrichment/solid-phase surface fluorescence.In the paper,we have established a method for quick determination of the trace polycyclic aromatic hydrocarbons (PAHs) in the water by using the solidphase surface spectrofluorimetry (SSF) nylon 6 nanofiber membrane prepared by self-made electro-spinning device known as the absorption material.As is well known,it is possible to use nylon 6 nanofiber membranes with their diameter being 5cm for filtrating the following 3 kinds of PAHs,that is,the solutions of phenanthrene,pyrene,fluoranthene,and then try to move the membranes to the powder sample pool with variable angles after air-drying,so as to identify and determine the 3-D excitation-emission solid-phase surface fluorescence spectra of PAHs with a fluorescence spectrophotometer.And,next,we have investigated and determined the excitation/emission wavelength pairs with the maximum fluorescence intensity in accordance with the 3-D excitation-emission solid-phase surface fluorescence spectra and the linear relationship between fluorescence intensity and the initial concentrati6n of each PAHs in the water.Thus,the results of the aforementioned study prove that:the excitation/emission wavelength with the maximum fluorescence intensity located at Ex/Em =255 nm/368 nm,Ex/Em =340 nm/376 nm and Ex/Em =290nm/437 nm for phenanthrene,pyrene,and fluoranthene,respectively.Furthermore,for the case of 500 mL the sample solution for the suction filtration,we have confirmed that the calibration curves between the fluorescence intensity and the initial concentration for three kinds of PAHs can properly be illustrated as follows:y =9432.4x + 261.1 with the linear concentration range between 5-500 ng/mL for phenanthrene,while y =753480x + 805.51 when the linear concentration range is within 0.2-10 ng/mL for pyrene and y =9946.06x + 603.48 with the linear concentration range being 10-400 ng/mL for fluoranthene.In addition,the detection limits should be set at 0.973 ng/mL whereas that of phenanthrene should be equal to 0.016 2 ng/mL and 0.089 6 ng/mL-for fluoranthene.Hence,for the standard solution of phenanthrene of 100 ng/mL,and pyrene of 10 ng/mL and fluoranthene of 50 ng/mL,may account for 7.0％,2.6％ and 5.1％,respectively,whereas the relative standard deviations (RSD) for the seven time determinations,and the relative errors of the mean values are to be 1％,2％ and-0.2％,correspondingly.As for the tap water with 50 ng/mL,200 ng/mL and 500 ng/mL of phenanthrene,their respective average recovery rates have been found equal to 87.2％-98.2％.But,for the tap water with the content concentrations of 0.5 ng/mL,2 ng/mL and 10 ng/mL pyrene,their average recovery rates account for 101％-120％.As to the tap water containing 10 ng/mL,50 ng/mL and 100 ng/mL fluoranthene,the respective average recovery rates should be 85.8％-92.3％,accordingly.Therefore,the method we have developed proves advantageous in simplicity,economy and high sensitivity,which is suitable for quick detection of the trace polycyclic aromatic hydrocarbons in all kinds of water.