镉污染土壤中吐纳麝香的生物有效性及其评价

Bioavailability of AHTN in cadmium-polluted soil and its assessment

采用室内盆栽实验,以小麦为供试植物,研究重金属镉(Cd)和吐纳麝香(AHTN)复合污染对小麦植株生物量的影响以及Cd对土壤中AHTN生物有效性的影响,并应用聚2,6-二苯基对苯醚(Tenax-TA)、固相微萃取纤维(SPME)和三油酸甘油酯-醋酸纤维素复合膜(TECAMs)对土壤中的AHTN进行提取,以评价Cd污染土壤中AHTN对小麦的生物有效性。结果表明:AHTN-Cd复合污染土壤中的小麦植株生物量低于单一AHTN污染土壤;当AHTN浓度为5 mg·kg^(-1)时,共存重金属Cd抑制AHTN在小麦地上和地下部的累积,其抑制作用随Cd浓度的增大而增强,抑制率最高达39.1%,AHTN在小麦体内从地下到地上的迁移随着Cd浓度的增加受到抑制,且浓度越高抑制作用越强,抑制率可达到19.0%;当AHTN浓度为10 mg·kg^(-1)时,共存重金属Cd则促进AHTN在植物体内的累积,其促进率高达38.4%,AHTN从地下到地上的迁移受到诱导,促进率高达68.5%;在AHTN和Cd单一及复合污染土壤中,Tenax 24 h、SPME 12 h和TECAMs 12 h单点提取AHTN的量与小麦根部AHTN富集量显著相关,表明Tenax 24 h、SPME12 h以及TECAMs 12 h对土壤中AHTN的提取量可以用来评价其生物有效性。

In an indoor pot experiment, biomass of wheat seedlings and accumulation of AHTN[1-（5,6,7,8-tetrahydro-3,5,5,6,8,8-hexamethyl-2-naphthalenyl-）-Ethanone] in wheat seedlings were investigated in a soil polluted by AHTN and Cd to examine the influences of Cd on the bioavailability of AHTN to the wheat seedlings. At the same time, Tenax-TA[poly（2,6-diphenyl-p-phenylene oxide）], SPME（Solid phase microextraction）fibers and TECAMs（Triolein embedded cellulose acetate membranes）were used to extract AHTN from soil and to assess the bioavailability of AHTN to wheat（Triticum aestivum）. Results showed that the biomass of wheat seedlings in AHTN-Cd treatment was lower than that in single AHTN treatment. At 5 mg·kg^（-1）of AHTN concentration, the accumulation of AHTN in different parts of wheat seedlings was inhibited by Cd, and the highest inhibition rate was 39.1%. The transfer of AHTN from the roots to the shoots slowed down in the presence of Cd, with the highest inhibition rate of 19.0%. At 10 mg·kg^（-1）of AHTN concentration, the accumulation of AHTN in wheat seedlings was induced by Cd, with the highest induction rate of 38.4%. The transfer of AHTN from the roots to the shoots was induced in the presence of Cd, and the highest induction rate was 68.5%. The concentrations of AHTN extracted by Tenax for 24 h, SPME for 12 h and TECAMs for 12 h correlated well with the concentrations in wheat roots, which indicated that Tenax 24 h, SPME 12 h and TECAMs 12h-extracted fractions could serve as a good predictor of the bioavailability of AHTN to wheat.