作　　者： ; ; ; ; ; ; ; ;

机构地区： 浙江万里学院生物与环境学院

出　　处： 《分析化学》 2017年第2期268-274,共7页

摘　　要： 建立了柱前衍生-气相色谱-电子捕获(GC-ECD)法同时测定水中PFBA、PFPeA、PFHxA、PFHpA,PFOA,PFNA,PFDA,PFUnA及PFDoA等(全称见正文)9种全氟羧酸(Perfluorinated carboxylic acids,PFCAs)。使用2,4-二氟苯胺(2,4-Difluoroaniline,2,4-DFA)为衍生剂,N,N'-二环己基碳二亚胺(N,N'-Dicyclohexylcarbodiimide,DCC)为脱水剂,与PFCAs形成酰胺衍生产物,衍生产物通过TR-5毛细管色谱柱分离,并以ECD检测器进行检测。对全氟羧酸衍生化过程中2,4-DFA和DCC用量、衍生反应溶剂、反应温度、反应时间等条件进行了优化,得出最佳衍生化条件。结果表明,在最优实验条件下,9种PFCAs衍生产物的线性相关系数>0.99,检出限为0.62~1.38μg/L,相对标准偏差RSD为1.3%~7.5%。应用本方法对城市污水中全氟类羧酸进行了分析,城市污水中存在以PFPeA、PFHpA和PFOA为主的痕量PFCAs化合物,实际样品的加标回收率在84.4%~120.9%之间。本方法稳定、可靠、成本低,能够满足水样中多种全氟羧酸的同时检测的要求,可为水体中全氟化合物的污染评价提供技术支持。 A method for the simultaneous determination of nine perfluorocarboxylic acids（PFCAs） in water by precolumn derivatization-gas chromatography-electron capture detector（GC-ECD） was established.PFCAs were firstly converted to amide derivative products using 2,4-difluoroaniline（2,4-DFA） as derivatizing agent and N,N＇-dicyclohexylcarbodiimide（DCC） as dehydrating agent.Then the amide derivative products were determined by ECD after separation with TR-5 capillary-column chromatography.The experimental conditions in derivatization of PFCAs were optimized,including the dosage of 2,4-DFA and DCC,reaction solvent,reaction temperature and reaction time.The optimal derivatization parameters were obtained.The results showed that the linear correlation coefficients of nine derivative products of PFCAs were higher than 0.99 under the optimized experimental conditions.The limits of detection were 0.62-1.38 μg/L,while the relative standard derivations RSDs were 1.3%-7.5%.The proposed method was applied to the analysis of PFCAs in municipal sewage.It was found that the municipal sewage contained trace PFCAs which mainly existed in the form of perfluoropentanoic acid（PFPe A）,perfloroheptanoic acid（PFHp A） and pentadecafluorooctanoic acid（PFOA）.The recoveries of actual samples were between 84.4% and 120.9%.The method was stable and reliable with low cost,and it could meet the simultaneous determination of several PFCAs in water samples.This study provided technical support for the pollution assessment of perfluorinated compounds in water.

关 键 词： 全氟羧酸 衍生化 气相色谱 电子捕获检测法 水体

领　　域： [理学] [理学]