电渗泵在顺序注射萃取法测定酚中的应用

Application of Electroosmotic Pump in the Determination of Phenols by Sequential Injection Analysis of Solvent Extraction

电渗泵是一种液流驱动泵 ,具有装置简单、载流无脉动、流量范围大和驱动电压适中等优点。用含 1mmol/L三乙醇胺和 0 .1mmol/L四丁基溴化铵的乙醇溶液作泵载流 ,采用顺序注射萃取 分光光度法 ,对水样挥发酚进行了测定。有机载流可避免产生界面 ,减小检测干扰。载流添加剂可提高泵流量 ,改善流量稳定性。另外 ,还研究了酚的各种萃取条件。水中酚的检出限为 7μg/L(3σ ,n =11) ;回收率为 92 %～ 94%。

Electroosmotic pump is a liquid driving apparatus, which has its advantages of simplified equipment, non-pulsing flow rate, large flow range and moderate working voltage etc.. In this paper, a sequential injection analysis system with an electroosmotic pump, of which ethanol solution containing 1 mmol/L triethanolamine and 0.1 mmol/L tetrabutylammonium bromide was used as the carrier, is proposed for on-line solvent extraction of phenols in water. With the organic solvent as the pump carrier, it can effectively prevent from the detection interference caused by liquid phase interface. Additives of the carrier can enhance and stabilize the pump flow rate. In addition, extraction conditions for phenols were also investigated. The detection limit of phenol was 7 mug/L (3sigma, n = 11) and the recoveries of the method were 92% similar to 94%. The proposed method confirms that electrokinetic flow analysis system can be employed in solvent extraction and organic analysis.