有机磷酸酯在重庆不同城市功能区土壤的分布特征及来源

Occurrence and Distribution of the Organophosphate Esters in Soils of Mixed-land Use Area in Chongqing City

本研究利用超高效液相色谱飞行时间质谱(UPLC-Q-TOF^-MS)检测分析了重庆市4个不同功能区城市表层土壤中12种有机磷酸酯(organophosphate esters,OPEs)含量水平,探讨了其组成特征,通过相关性分析讨论了土壤有机质(soil organic matter,SOM)与ΣOPEs及各单体含量之间的关系,利用主成分分析阐述了OPEs可能的来源.结果表明,ΣOPEs含量(以干重计,下同)范围为10. 7～108 ng·g^(-1),平均值为46. 4 ng·g^(-1),处于国内外较低水平;不同功能区土壤中ΣOPEs平均含量大小依次为:工业区(55. 6 ng·g^(-1)),住宅区(55. 5 ng·g^(-1)),商业区(41. 8 ng·g^(-1)),城市公园(34. 1 ng·g^(-1)).磷酸三(2-氯异丙基)酯(TCPP)和2-乙基己基二苯基磷酸酯(EHDPP)是主要OPEs污染物单体,TCPP在工业区土壤贡献率最高达到了31. 5%,而EHDPP在商业区和城市公园贡献率最高分别为23. 4%和24. 7%.相关性分析表明SOM含量和ΣOPEs含量呈显著相关(P <0. 05),和单体磷酸三甲苯酯(TCP)含量呈极显著相关(P <0. 01),表明SOM是影响OPEs分布的因素之一.主成分分析表明城市土壤OPEs来源并不单一,污水灌溉、路面径流、室内源污染及污泥再利用等都可能成为土壤OPEs潜在来源途径.

Organophosphate esters（ OPEs） in surface soil of four different functional areas in Chongqing were identified and quantified using ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry（ UPLC-Q-TOF^-MS）. The composition and characteristics of OPEs were discussed along with the relationships between soil organic matter（ SOM） and OPEs through correlation analysis,and possible sources of OPEs were simultaneously investigated through principal component analysis（ PCA）. The results showed that the concentrations of Σ OPEs ranged from 10. 7 to 108 ng·g^-1 dry weight,with a mean concentration of 46. 4 ng·g^-1,which was at the low-level end of the global figure. The average concentration was 55. 6 ng·g^-1 in the industrial area,55. 5 ng·g^-1 in the residential area,41. 8 ng·g^-1 in the commercial area,and 34. 1 ng·g^-1 in the city park. Tris（ 1-chloro-2-propyl） phosphate（ TCPP） and 2-ethylhexyl diphenyl phosphate（ EHDPP） were dominant compounds,contributing up to 31. 5% in the industrial area for TCPP and23. 4% and 24. 7% in the commercial area and city park,respectively,for EHDPP. Significant relationships between concentrations of SOM and Σ OPEs（ P 0. 05） and tricresyl phosphate（ TCP）（ P 0. 01）,respectively,indicated that SOM was a factor affecting the concentration and distribution of the OPEs. The PCA suggested that there were multiple sources of OPEs in urban soil. Sewage irrigation,road runoff,indoor source pollution,and sludge reuse could be potential sources of soil OPEs.