中文摘要：

在常温下,水合氯醛与NaOH反应可生成氯仿;随着CaCl2的加入,分散到水溶液中的氯仿微液滴可迅速沉降到离心管底部。基于此,本研究建立不用分散剂,无需离心处理的新型分散液-液萃取技术,并选择3种常见的芳香胺作为目标物,检验这种新型萃取方法的可行性。为与所用的水基电解质体系毛细管电泳分离方法（80mmol/LH3PO4-60mmol/LTris,pH2.6）契合,用含有K＋的酸性电解质溶液（80mmol/LKH2PO4-5mmol/LH3PO4,pH2.85）通过反萃法将分析物重新转移到水相,进而可实现瞬时等速毛细管电泳堆积富集和区带电泳分离检测。考察了水合氯醛与NaOH用量对氯仿生成量及萃取效果的影响,还研究了沉淀剂的种类和用量、萃取时间及酸性反萃剂的组成等对萃取物峰面积的影响。在最佳条件下,每个样品的分析时间小于8min,联苯胺、N-甲基苯胺和间甲基苯胺的检出限分别为0.20,1.23和1.08mg/L,对于自来水样和雨水样的平均加标回收率为80.7%～110.2%。本方法的检出限优于文献报道结果。

英文摘要：

A new dispersive liquid-liquid microextraction （DLLME） was developed on the basis of two phenomena, chloroform can be generated by the reaction of chloral hydrate and sodium hydroxide, and the chloroform droplets dispersed into bulk aqueous solution can be swiftly carried to the bottom of the centrifuge tube with the addition of calcium chloride. The advantages of the new DLLME lie in dispersive solvent free and centrifugation operation compared with the conventional DLLME. Three common aromatic amines were chosen as the analytes to verify the feasibility of the new DLLME method. These compounds were analyzed by capillary zone electrophoresis （CZE） with the background electrolyte aqueous solution containing 80 mmol/L H3PO4＋ 60 mmol/L Tris （pH =2.6）. Considering the compatibility of the resultant sample solution and separation media in CZE, a back-extraction technique was performed by an acidic electrolyte solution containing potassium ion （ 80 mmol/L KHzPO4 ＋ 5 mmol/L H3PO4, pH = 2.85 ） to transfer these aromatic amines from chloroform phase to aqueous phase which was helpful to complete transient isotachophoresis stacking on the capillary. The effects of the amounts of chloral hydrate and sodium hydroxide, the kinds and amounts of inorganic salts added, extraction time and the composition of the back-extraction solution on the peak areas for the three compounds were investigated. Under optimum conditions, it took less than 8 min to complete sample preparation and analytsis for each sample. The LODs for benzidine, N-methylaniline and m-toluidine were 0.20, 1.23 and 1.08 μg/L, respectively, which were better than those recently reported values with other methods. The average recoveries for three compounds were within 80.7% -110.2% when tap water and rain water were analyzed.