淮河流域土壤中全氟化合物的空间分布及组成特征

为了阐明淮河流域土壤中全氟化合物(PFCs)的暴露特征和潜在来源,2008年10月在淮河安徽段共采集了18个表层土壤样品,通过离子燃烧色谱(CIC)测定总氟(TF)和可提取有机氟(EOF),以及采用高效液相色谱/质谱联用(HPLC/MS-MS)分析了16种PFCs,其中11种PFCs有不同程度的检出.PFCs含量为n.d.～1.22 ng·g-1,其中全氟辛酸(PFOA)、全氟壬酸(PFNA)和全氟辛烷磺酸(PFOS)是主要的PFCs.在这些土壤样品中,PFCs含量相差不大,但组成不一,主要来源于周边小型化工厂的排放以及大气的干湿沉降.利用氟原子质量平衡原理,分析得出PFCs占EOF比例为0.3%,EOF占TF比例为0.02%,一方面说明除PFCs外仍有很大一部分可提取有机氟难以定性和定量,且离子态氟及未提取出的有机氟是TF的主要成分,另一方面受现有标准物质和检测技术限制,尚不能完全甄别和分析出PFCs的含量及未知的有机氟.

Spatial Distribution and Composition of Perfluorinated Compounds in Soils Around the Huaihe River

In order to analyze the occurrence and composition of perfluorinated compounds (PFCs), 18 topsoil samples were collected around the Huaihe River in October, 2008. Total fluoride (TF) and extractable organic fluorine (EOF) were determined using combustion ion chromatography (CIC), and PFCs were quantified by HPLC/MS-MS. Among the sixteen PFCs analyzed, eleven PFCs were detected. Concentrations of PFCs ranged from n.d. to 1.22 ng·g^-1, and perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA) and perfluorooctane sulfonate (PFOS) were the predominant PFCs. Concentrations of PFCs showed no significant difference, but compositions varied from soil to soil. PFCs mainly came from emissions of local small chemical plants and atmospheric dry and wet deposition. The results from mass balance analysis indicated that PFCs only accounted for 0.3% of EOF and EOF comprised 0.02% of TF. There was still a large amount of organic fluorine besides PFCs, and inorganic fluorine and non-extractable organic fluorine comprised the major portion of TF. Furthermore, the current analysis method could not detect all kinds of PFCs and related unknown organic fluorine.