沈阳市降雪中PFOS和PFOA污染现状调查

通过调查降雪中PFOS和PFOA的浓度,阐明了沈阳市大气中PFOS和PFOA的污染状况和污染规律.2006-02-06采集沈阳市区和郊区共计36个采样点的降雪样品,2006-02-25在其中5个采样点再次采集降雪样品.固相萃取融雪水中的PFOS和PFOA,利用LC-MS-SIM法测定样品中PFOS和PFOA浓度.全部样品中均检出PFOS和PFOA.2006-02-06降雪中PFOS和PFOA的浓度几何平均值分别为2.0 ng·L^-1（范围：0.4～46.2 ng·L^-1）和3.6 ng·L^-1（范围：1.6～22.4 ng·L^-1）,95%置信区间分别为1.5～2.8 ng·L^-1和3.1～4.2 ng·L^-1.PFOS和PFOA的最高浓度同时出现在郊区采样点朱尔屯,市中心区2种物质的浓度呈显著正相关.2006-02-25的5个采样点降雪中PFOS和PFOA的浓度几何平均值均为2.2 ng·L^-1.2次降雪中PFOS浓度差异不显著,2006-02-25降雪中PFOA浓度高于2006-02-06.结果表明,沈阳市区和郊区降雪中广泛存在PFOS和PFOA污染,局部区域可能存在共同的PFOS和PFOA污染来源;沈阳地区有较稳定的PFOS来源持续向大气中输送该类物质;PFOS和PFOA的环境行为可能不同.

Investigation of PFOS and PFOA Pollution in Snow in Shenyang, China

The purpose of this study was to investigate the atmospheric perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) pollution in Shenyang by analyzing the concentration of the two compounds in snow. Snow samples were collected from both urban and suburban areas on Feb. 6 (n=36) and Feb. 25 (n=5) in 2006 in Shenyang, China. PFOS and PFOA were extracted from the snowmelt by solid phase extraction and then were analyzed by LC-MS-SIM. PFOS and PFOA were discernable in all the samples. In the snow samples collected on Feb. 6, 2006, the geometric average concentrations of PFOS and PFOA were 2.0 ng x L(-1) (range: 0.4-46.2 ng x L(-1)) and 3.6 ng x L(-1) (range: 1.6-22.4 ng x L(-1)), respectively. The 95% confidence intervals of PFOS and PFOA were 1.5-2.8 ng x L(-1) and 3.1-4.2 ng x L(-1), respectively. The concentration of PFOS and PFOA showed significant correlation at the center of Shenyang City (n=9), while the highest concentrations of PFOS and PFOA were detected at the same site located in the rural area. Geometric average concentrations of PFOS and PFOA were both 2.2 ng x L(-1) in the Feb. 25 snow samples. Concentrations of PFOS in two snow events did not show significant difference. Whereas PFOA concentration in Feb. 25 snow was higher than that in Feb. 6 snow. Results suggested the widespread PFOS and PFOA pollution in snow in Shenyang. There may be similar resources for the two compounds in regional area. Moreover, there may be continual import of PFOS to the atmosphere in Shenyang from specific resources, while PFOS and PFOA may exhibit different environmental behavior.