红枫湖流域表层沉积物中全氟化合物的污染特征

PFCs(perfluorinated compounds, 全氟化合物)因具有持久性、生物富集效应和毒性而受到环境科学领域的普遍关注. 采用超高效液相色谱-串联质谱联用仪(UPLC-MS/MS)并结合固相萃取的方法,对贵阳市主要饮用水水源地——红枫湖主要入湖支流及湖区表层沉积物中10种PFCs的质量分数进行了检测,分析了其污染水平、空间分布及组成特征. 结果表明,各采样点w(∑PFCs)(10种PFCs的总质量分数)为0.27~1.65 ng/g,其中PFBA(全氟丁酸)、PFPeA(全氟戊酸)、PFOA(全氟辛酸)、PFBS(全氟丁烷磺酸)、PFOS(全氟辛烷磺酸)及PFHxA(全氟己酸)不仅检出率高,而且对各采样点w(∑PFCs)的贡献较大,是红枫湖表层沉积物中主要的PFCs；受湖区水文水动力条件及沉积物有机质的影响,北湖表层沉积物中w(∑PFCs)高于南湖,并且全湖w(∑PFCs)的最高值位于出湖口处,达到1.65 ng/g；红枫湖流域表层沉积物中的w(PFOA)和w(PFOS)分别为0.07~0.51和nd(未检出)~0.16 ng/g,与国内外其他流域相比处于较低水平；大气沉降可能是红枫湖流域PFCs的主要来源. 

Contamination Profiles of Perfluorinated Substances in Surface Sediments of Hongfeng Lake Basin

Abstract:Over the past few years, perfluorinated compounds (PFCs) have attracted much attention because of their persistence and wide existence in different environments. The occurrences of ten PFCs in surface sediments of Hongfeng Lake and its tributaries were analyzed via high performance liquid chromatography-tandem mass spectrometry combined with solid phase extraction. The content of PFCs (w(∑PFCs)) were 0.27-1.65 ng/g dry weight. PFBA, PFPeA, PFOA, PFBS, PFOS and PFHxA were dominant among PFC contaminants with high detection rates and contributions. The average level of w(∑PFCs) in the north of the lake was higher than that in the south. The maximum concentration of ∑PFCs, 1.65 ng/g, was found in the export position, which was affected by the hydrodynamic conditions of the lake and the content of the organic matter in the surface sediments. The levels of w(PFOA) and w(PFOS) in the surface sediments of Hongfeng Lake were 0.07-0.51 ng/g and nd-0.16 ng/g respectively, which were in the lower contamination level compared with other basins around the world. The main potential source of PFCs in Hongfeng Lake was possibly atmospheric deposition.