磷矿复垦地马铃薯镉和铅含量及分布规律

Analysis on Cadmium and Lead in Whole Potato Plant from Phosphorite Reclaimed Land

利用火焰原子吸收法测定了种植于磷矿复垦地马铃薯植株不同器官中镉(Cd)、铅(Pb)重金属的含量。结果表明,在磷矿复垦地土壤Cd、Pb含量高于土壤无机污染物的二级标准条件下,马铃薯块茎中Cd、Pb含量都超过安全食用标准;马铃薯植株中不同器官Cd、Pb的分布具有明显规律,块茎、根、茎、叶的含量差异显著,呈逐渐增加趋势,叶片是积累2种重金属含量最多的器官,块茎含量最低;随生育期延长,成熟期马铃薯根、茎、叶中的Cd含量较现蕾期略有增加。马铃薯各器官对2种重金属元素的富集系数不同,对Cd的富集作用明显大于对Pb的富集作用,因此即使在低Cd土壤中种植马铃薯也需要谨慎选择。

The content of cadmium and lead existing in potato plant in the phosphorite reclaimed land was determined by using flame atomic absorption spectrometry. The results showed that the total cadmium and lead content of soils exceeded the secondary standard of the environmental quality of soil inorganic pollutants, and both element contents in potato tuber exceeded the food safety standard; the distribution of cadmium and lead in various parts of the potato plant had obvious patterns, and the contents of both elements in various organs showed significant difference and increased gradually in the potato tuber, root, stem and leaf, with leaf containing the highest content of both elements and tuber the lowest; along with the advance of the growth, the content of cadmium in each organ of potato plant at maturity was a little bit higher than that at flower bud stage. The data also showed that the bioconcentration factor of cadmium was markedly higher than that of lead,suggesting that planting potato should be more cautious even in a low concentration of cadmium contaminated soils.