Occurrence and distribution of perfluorinated compounds in surface water of Lake Qiandao(Xin'anjiang Reservoir

Abstract

为查明千岛湖水体中全氟化合物（PFCs）的污染特征，于2017年丰水期和枯水期分别采集13个监测断面的表层水样品，采用固相萃取净化、富集水样，超高效液相色谱-串联质谱联用法测定水中16种PFCs，研究其残留水平和分布特征.监测结果表明，千岛湖表层水共检出5种中短链PFCs，包括C₄全氟烷基磺酸以及C₄、C₅、C₆和C₈ 4种全氟烷基羧酸.ΣPFCs浓度范围为1.70～6.21 ng/L，以全氟辛酸（PFOA）为主要污染物，其浓度范围为0.52～3.61 ng/L，全氟辛烷磺酸（PFOS）则未检出.与国内外同类水体相比，PFOA和PFOS浓度水平均处于低污染水平.枯水期千岛湖水中PFCs污染程度高于丰水期，整体上呈现点源污染特征.各断面水体中ΣPFCs浓度枯水期差异较大，而丰水期基本处于同一浓度水平.空间分布上主要入湖河流新安江上游断面街口和威坪的PFCs浓度明显高于其他主要入湖河流断面以及湖区断面.;This study investigated the occurrence and distribution of perfluorinated compounds (PFCs) in surface water of Lake Qiandao. Surface water samples, collected from 13 sites in the lake were analyzed for 16 PFCs during wet and dry seasons in 2017. All samples were prepared by solid-phase extraction and analyzed using the ultra performance liquid chromatography interfaced to tandem mass spectrometry (UPLC-MS/MS). The results showed that 5 medium- and short-chain PFCs including C₄ perfluorinated sulfonate (PFSA) and C₄-C₆ and C₈ perfluorinated carboxylic acids (PFCAs) were detected in the surface water. The total concentrations of PFCs ranged from 1.70 to 6.21 ng/L, while perfluorooctanoic acid (PFOA) dominated, with ranges of 0.52-3.61 ng/L, and perfluorooctane sulfonate (PFOS) was not detected in all samples. Compared with other similar water bodies at home and abroad, the concentrations of PFOA and PFOS in Lake Qiandao were at low pollution levels. The ΣPFCs concentrations in surface water of most sites were higher in dry season than those in wet season, implying that it was from the point-source, and the spatial distribution varied more significantly among sampling sites in the dry season. The mass concentration of PFCs at the sampling sites located in upstream of the Xin'an River, the mainstream of the lake, such as Jiankou and Weiping were relatively high.