全氟辛酸的3,4-二氯苯胺衍生化及高效液相色谱分析

介绍了一种可用于环境污染物全氟辛酸（PFOA）检测的高效液相色谱/紫外检测（HPLC/UV）分析方法。首先选用3，4-二氯苯胺为衍生化试剂，利用碳二亚胺法合成PFOA的酰胺化衍生产物（其在255 nm处紫外吸收最大）。然后确定四氢呋喃或水相介质中mg/L水平PFOA的衍生化条件及薄层硅胶色谱净化步骤。建立柱前衍生-HPLC/UV方法，以合成的全氟辛酸-3，4-二氯苯酰胺为对照品，外标法定量，PFOA上机测定的定量限为0.5 mg/L。通过加标回收试验评价方法的准确性，其中有机相及水相衍生法的回收率分别为91.8%~108.7%及40.1%~53.7%。与已报道的柱前衍生-HPLC/UV方法比较，本方法具有反应条件温和、衍生产物稳定、原料廉价易得、操作简单、成本低等优点。将本方法应用于光催化降解研究中PFOA的降解动力学实验，结果与液相色谱-质谱联用方法（LC/MS）的结果一致，说明本方法具有较好的应用前景。

Analysis of perfluorooctanoic acid by high performance liquid chromatography with 3,4-dichloroaniline derivatization

A simple derivatization method followed by high performance liquid chromatography (HPLC) for the analysis of perfluorooctanoic acid (PFOA) was developed. PFOA was firstly derivatized with 3,4-dichloroaniline (DCA) using carbodiimide method. The typical amidate product was characterized by mass spectrometry (MS). It can be detected by a UV detector at maximum absorption wavelength of 255 nm. It was isolated well by methanol/H₂O (8/2, v/v) as mobile phase. The DCA derivatization of PFOA in organic or aqueous solutions was optimized. The following purification procedures with thin layer chromatography (TLC) and HPLC separations were established. Using external standard method with the authentic PFOA-DCA derivative as standard, the limit of instrumental quantification was found to be 0.5 mg/L. Good linear correlation coefficients were observed in 0.5-50.0 mg/L. The accuracy of the method was evaluated by the recovery measurements on spiked samples. The recoveries for the spiked samples (1.0 mg/L) in organic phase and aqueous phase were 91.8%-108.7% and 42.1%-53.7%, respectively. Comparing to the reported pre-column derivatization methods followed by HPLC for the determination of PFOA, this method has the advantages of mild reaction conditions, very stable derivative, easy operation, low cost, etc. The method was successfully applied for the quantification of PFOA in photodegradation experiments, and the results were consistent with those determined by LC/MS. Considering the combination of the preconcentration step, it has a potential for the application of the analysis of samples containing relatively low concentrations, such as μg/L levels of PFOA obtained from environmental or scientific experiments.