【作者】 李文超；

【导师】 杨绍贵；

【作者基本信息】 南京大学 ， 环境科学， 2012， 硕士

【摘要】 固相微萃取技术(Solid phase microextraction, SPME)是以固相萃取为基础研发出的一种新型样品前处理方法。由于商品化的SPME涂层普遍存在耐高温性能和耐溶剂性能较差,使用寿命短和价格偏高等缺点,新型涂层的研发一直是该领域的研究热点。聚(甲基丙烯酸—乙二醇二甲基丙烯酸酯)(Poly (MAA-EGDMA))是一种非常理想的吸附剂,近年来这种材料被用在管内固相微萃取(Intube-SPME)和整体柱材料固相微萃取(PMME)中用于测定生物组织中的碱性药物。但是这两种装置都需要额外的辅助装置,而将这种材料制备成SPME纤维涂层还未见报道。本论文分别选用石英纤维和不锈钢丝作为基体,使用石英毛细管作为模具,采用原位聚合法制备Poly (MAA-EGDMA) SPME纤维涂层。探讨制备条件对涂层形貌以及萃取效果的影响。优化萃取条件后将自制的涂层用于测定水样中氯酚类有机污染物和血清中的多氯联苯类有机污染物。主要研究工作和结果如下：(1)研究采用石英毛细管作为模具以石英纤维为基体制备Poly (MAA-EGDMA)固相微萃取纤维涂层的方法,并与气相色谱联用建立检测水中4种氯酚的分析方法。结果表明,MAA与EGDMA的比例、聚合溶剂和聚合时间均会影响涂层的形貌和萃取效果；在最优制备条件下制备出的涂层均匀致密,厚度统一(约30μm),在100-300℃范围内保持热稳定性,且涂层制备重现性较好(批内RSD<11.3(%,n=7),批间RSD<15.3%,(n=3))；在相同萃取条件下其萃取效果与85μm PA商用纤维涂层相当。通过正交试验得到萃取水样中氯酚类物质的最优条件为：15mL pH=2的饱和盐浓度水样在60℃下萃取50min,搅拌速度为1050rpm。所建立的方法灵敏度高、检测限较低(小于10ng/L),线性范围宽,精密度较好(RSD<8.9%(n=5)),在实际自来水样和太湖水样中均有4种氯酚被检出,满足实际环境样品痕量分析的要求。(2)研究利用聚多巴胺的超强附着特性修饰不锈钢丝表面,并将其作为纤维基体制备Poly (MAA-EGDMA)涂层,与气相色谱联用建立检测血清样品中多氯联苯类有机污染物的分析方法。选择乙醇和乙酸乙酯两种溶剂混合作为聚合溶剂,结果表明溶剂的比例会影响涂层的形貌和萃取效果,通过比较萃取效果确定最佳溶剂比例。自制涂层均匀致密,呈多孔结构,厚度统一(约30μm),耐受温度为280℃,其萃取6种多氯联苯的效果远远优于商品化的萃取纤维30μm PDMS,可与65μm PDMS/DVB商品化涂层相媲美。优化了萃取模式、血清稀释比例、萃取温度和萃取时间,得到最优的萃取条件为0.5mL血清中加入1mLPBS缓冲溶液稀释,在70℃下萃取30min,搅拌速度为1050rpm,萃取完成后立即插入GC进样口,在270℃下解析5mmin。该方法的检测限为1-4ng/mL,线性范围为5-100ng/mL,线性相关系数较好(均大于0.99),精密度也较好(RSD<9.8%,n=5)。虽然在实际血清样品中没有PCBs的检出,但是加标回收率范围在78.3～110.6%,RSD(%,n=3)范围在1.94-10.5,说明该方法具有一定的准确度。更多还原

【Abstract】 Solid phase microextraction (SPME) which was developed based on solid phase extraction is one of popular sample preparation techniques. Development of new coating material is always the research hotspot of SPME, scince some commercial fibers have several drawbacks such as lack of non-resistance to high temperature and organic solvents, high cost and short life. Poly (methacrylic acid-ethylene glycol dimethacrylate)(MAA-EGDMA) material which would appear as an ideal sorbent was used as the martial of Intube-SPME and PMME rencently for detection of basic drugs from biological samples. But both of them need additional auxiliary devices. However, there are no reports about preparation of poly (MAA-EGDMA) as SPME fiber coating.In this thesis, a novel and simple method was first developed to prepare a poly (MAA-EGDMA) coated SPME fiber using a glass capillary as a "mold" and silica fiber or steel wire as substrate. Some polymerization parameters affecting the morphology and extraction efficiency of coatings were optimized.The homemade fibers combined with gas chromatography was designed to determine chlorophnenol from water sample and polychlorinated biphenyls(PCBs) from serum sample under optimum extraction conditions. The main works of this paper are as follows:(1) A novel and simple method was first developed to prepare a poly (MAA-EGDMA) coated SPME fiber using a glass capillary as a "mold" and silica fiber as substrate. In combination with GC, the method for determination of PCBs from serum sample was proposed. The results showed that the ratio of MAA and EGDMA, polymerization solvent and polymerization time can affect the morphology and extraction efficiency of coatings.The homemade coating prepared under the optimum showed a highly cross-linked, porous and homogeneous structure, which was thermally stable up to300°C. The fiber-to-fiber reproducibility was acceptable. The extraction capability of coating can compare to85um PA commercial SPME fiber which is often used to analyze chlorphenols. Optimization of extraction conditions were extraction temperature of60°C, extraction time of50min, stir speed of1050rpm, saturated NaCl and pH of2, which were carried out by orthogonal array experimental design. Under the optimum conditions, the detection limits were in the range of0.1-10ng/L, linear range was0.2-50ng/mL for target analytes, the correlation coefficients were all greater than0.99, and relative standard deviation was less than8.9%, which could meet the practical requirements of trace analysis of environmental samples. Four cholorphenols were detected from tap water and lake water samples by using the proposed method, and the recoveries of spiked natural water samples were ranged from91.8%to110.8%and90.6%to111.4%for tap and lake water samples, respectively.(2) The adhesive mechanisms of polydopamine were applied for using steel wire as substrate to prepare poly (MAA-EGDMA) coated SPME fiber. In combination with GC-uECD, the method for determination of PCBs from serum sample was proposed. The ratio of two polymerization solvent can affect the morphology and extraction efficiency of coatings. The optimum ratio was determined by comparing the extraction efficiency of PCBs. The coating showed a porous and homogeneous structure, which was thermally stable up to280°C. The extraction capability of coating was better than30u.m PDMS commercial SPME fiber and can compare to85μm PA commercial SPME fiber. The optimum extraction coditions were dilution rate of1:2, extraction temperature of70°C, extraction time of30min, stir speed of1050rpm, desorption temperature of270°C. Coupled with GC-μECD, the method detection limits range for determination of PCBs from serum sample were1-4ng/mL, linear range was5-100ng/mL, the correlation coefficients were all greater than0.99, relative standard deviation was less than9.8%, and the recoveries of spiked serum samples were ranged from78.3%to110.6%.更多还原