多壁碳纳米管固相微萃取纤维制备及其在海水中多溴联苯测定中的应用
Preparation of multi-walled carbon nanotubes coated solid-phase microextraction fiber and its application on the analysis of polybromobiphenyls in seawater
摘要
通过以nAfIOn为黏合剂、不锈钢丝为涂层载体,制备了多壁碳纳米管固相微萃取纤维.该纤维的制备方法快速、简便、成本低,并具有热稳定性好(300℃)、使用寿命长(>100次)、对多溴联苯萃取效率高等特点.研究优化了影响萃取及分离效率的解吸温度和时间、萃取时间、搅拌速度、盐度等实验条件,进行了海水中多溴联苯的测定.对一溴联苯的线性范围为0.1~5.0ng/Ml,而二溴联苯、三溴联苯、四溴联苯和五溴联苯的线性范围均为0.01~5.0ng/Ml.方法的检测限为0.1~0.8ng/l.在优化的条件下分别测定了0.1和1ng/Ml多溴联苯的海水加标样品,回收率在91.1%~107.3%之间,相对标准偏差小于12%.该方法分析时间短、灵敏度高、操作简便,适用于水样中多溴联苯的痕量分析. In this study, we proposed an approach using Nafion as a binder to immobilize multi-walled carbon nanotubes (MWCNTs) on a stainless steel wire base to prepare MWCNTs-coated fiber.The preparation method is fast, simple and low-cost.The MWCNTs-coated fiber shows high affinity towards polybromobiphenyls (PBBs), and mechanical and thermal stability.The experimental parameters related to extraction efficiency including desorption temperature and time, extraction time, stirring rate, salt concentration were investigated and optimized.The linearity was found to be from 0.1 to 5.0 ng/mL for monobromobiphenyl (mono-BB), and 0.01 to 5.0 ng/mL for dibromobiphenyl (Di-BB), tribromobiphenyl (Tri-BB), tetrabromobiphenyl (Tetra-BB) and pentabromobiphenyl (Penta-BB).The detection limits of these PBBs were between 0.1 and 0.8 ng/L.The recovery of the PBBs spiked in sea water at 0.1 ng/mL and 1 ng/mL ranged from 91.1% to 107.3%, and the relative standard deviations were less than 12%.The proposed method which is sensitive, fast and easy to operate could be applied to the determination of trace-level PBBs in water samples.