Tenax-TA提取和固相微萃取预测土壤中PAHs对蚯蚓的生物有效性

Prediction of the bioavailability of PAHs in earthworms by Tenax-TA and solid phase microextraction

为了准确预测土壤中多环芳烃(PAHs)的生物有效性,采用Tenax-TA提取和固相微萃取(SPME)法提取焦化厂土壤中的PAHs,并评价PAHs对赤子爱胜蚯蚓(Eisenia fetida)的生物有效性,分析PAHs Tenax-TA快速解吸组分提取量和SPME预测量与蚯蚓体内含量的差异及相关关系。结果表明:蚯蚓体内蓄积的PAHs浓度与土壤中PAHs浓度、SPME预测浓度、Tenax-TA快速解吸组分提取量均存在显著相关关系(R2分别为0.88、0.55和0.94),但与土壤中孔隙水浓度不存在明显的相关性;SPME预测高估了蚯蚓体内PAHs的浓度,而Tenax-TA快速解吸组分提取与蚯蚓体内浓度的比值接近于1;Tenax-TA快速提取量比SPME纤维丝能更好地预测焦化厂土壤中PAHs对蚯蚓的生物有效性,这为PAHs污染土壤的环境风险评价和修复提供了理论依据。

In order to accurately predict the bioavailability of PAHs in coking plant soil, Tenax-TA extraction of PAH fast desorption fraction and solid phase microextraction （SPME） were applied in this study to predict the PAHs concentration in earthworms （Eisenia fetida）, and the data were compared with measured PAHs concentration in earthworms to analyze their difference and correlation. The results showed that the PAHs concentrations measured in earthworms were linearly related with those in bulk soil and those predicted by SPME and Tenax （R^2=0.88, 0.55 and 0.94, respectively）. There was no relationship between the PAHs concentration in earthworms and that in soil pore water predicted by SPME. While SPME somewhat overestimated PAHs concentration in earthworms, Tenax predicted it with a ratio nearly to 1∶1, which indicates that Tenax-TA extraction of PAH fast desorption fraction in coking plant soil may serve as a better predictor to assess PAHs bioavailability. Our results provided a theoretical basis for the environmental risk evaluation and remediation of PAHs polluted soil.