萝卜对邻苯二甲酸酯(PAEs)吸收累积特征及途径的初步研究

利用玻璃室处理和覆土处理(人工污染土壤上覆盖原土壤)的方法控制萝卜的PAEs来源进行盆栽试验,试验处理分别为:(1)原土壤,暴露于大气中(空白1);(2)原土壤,置于玻璃室中(空白2);(3)人工污染土壤,暴露于大气中;(4)人工污染土壤,置于玻璃室中;(5)人工污染土壤上覆盖2 cm厚原土壤,暴露于大气中;(6)人工污染土壤上覆盖2 cm厚原土壤,置于玻璃室中.盆栽后应用GC/MS对土壤和植株样品中的PAEs进行分析,初步研究了萝卜对PAEs的吸收累积特征及途径.研究结果表明,萝卜茎叶和直根中邻苯二甲酸二乙酯(DEP)的含量均低于检测限,邻苯二甲酸正二丁酯(DBP)和邻苯二甲酸二(2-乙基己基)酯(DEHP)的含量与土壤污染浓度成正相关关系,DBP的含量高于DE-HP,两者主要分布在茎叶中.未覆土处理与覆土处理相比,前者盆栽的萝卜茎叶中DBP和DEHP的含量均高于后者,但在2个处理之间差异不显著,表明萝卜茎叶可以吸收污染土壤中挥发出来的DBP和DEHP,但直根吸收运移是茎叶中DBP和DEHP的主要来源途径.玻璃室处理导致萝卜茎叶中DBP含量的提高,在大棚蔬菜生产中值得注意.

Possible pathways through which phthalic acid esters (PAEs) are accumulated in radish plants (Raphanus Sativus)

A pot experiment was conducted to investigate the possible pathways through which PAEs are accumulated in radish plants(Raphanus Sativus).Six treatments were set in the experiment: (1) untreated soil in open air (served as Control 1), (2) untreated soil in a greenhouse (served as Control 2), (3) artificially contaminated soil in open air, (4) artificially contaminated soil in a greenhouse, (5) artificially contaminated soil capped with a thin layer of untreated soil in open air, and (6) artificially contaminated soil capped with a thin layer of untreated soil in a greenhouse. The concentrations of PAEs in shoots and roots were detected by gas chromatography-mass spectrum (GC/MS).The results showed that the concentrations of DEP in both roots and shoots of radish plants for all the treatments were below the detection limit. The concentrations of DBP and DEHP in both shoots and roots were positively related to those in the soils. Both DBP and DEHP were mainly occurred in shoots with the concentration of DBP being higher than that of DEHP in the same shoot. Concentrations of both DBP and DEHP in shoots were only slightly higher in the plant grown in the uncapped soil than in the corresponding capped soil, indicating that the accumulation of DBP and DEHP in the shoots of radish were primarily through root uptake, shoot uptake of DBP and DEHP volatilizing from polluted soil was minor. It was also found that the concentrations of DBP in shoots were higher in the radish plants grown in the glasshouse than in the open air. WTHZ]