基于新型被动采样校正技术的塑化剂大气垂直浓度梯度研究

Atmospheric vertical distribution of plasticizers based on a new passive air sampling calibration method

改进了垂直浓度梯度被动采样器和采样速率校正方法,并利用其考察有机磷酸酯(OPEs)和邻苯二甲酸酯(PAEs)两种塑化剂在土壤垂直方向上的采样速率、浓度分布及土-气交换趋势.为了更准确地获得采样速率,利用主动采样和添加效能参考物质(DCs)联合校正被动采样速率;得到OPEs和PAEs经主动-DCs联合校正的采样速率分别为0.27—3.16 m^(3)·d^(−1)和0.23—3.25 m^(3)·d^(−1).基于主动-DCs联合校正得到的污染物浓度相比单独主动校正的结果差异显著,进而导致化合物土-气扩散趋势发生显著变化.部分物质如TIBP、TCEP、TCIPP、TPHP、TPPO、DMP、DEP等甚至出现从沉降到挥发的趋势反转.由于引入DCs校正了环境因素的影响,因此主动-DCs联合校正的被动采样速率能够获得更准确的污染物环境浓度和交换趋势.

The vertical passive air sampler and its sampling rate calibration method were improved.The sampling rates,distributions and soil-air exchange trends of organophosphate esters(OPEs)and phthalates(PAEs)in the vertical direction of soil surface were studied.In order to obtain a more accurate result,the sampling rate was calculated by a joint calibration using both active sampling and performance reference compounds(DCs).Sampling rates of OPEs and PAEs calibrated by the joint calibration of active sampling-DCs were in the range of 0.27—3.16 m^(3)·d^(−1)and 0.23—3.25 m^(3)·d^(−1),respectively.Significant differences were found between the concentrations of compounds obtained by calibration of active sampling-DCs and by only active sampling,as well as their air-soil exchange trends.Some compounds,such as TIBP,TCEP,TCIPP,TPHP,TPPO,DMP and DEP,even showed a reverse air-soil exchange trend from deposition to volatilization.The method using active sampling-DCs joint calibration can obtain more accurate passive air sampling rates,concentrations and exchange trends of contaminants,since the addition of DCs corrects the influence of environmental factors.