Sadowska Monika, Biaduń Ewa, Krasnodębska-Ostręga Beata
Faculty of Chemistry, University of Warsaw, ul. Pasteura 1, 02-093 Warsaw, Poland.
Faculty of Chemistry, University of Warsaw, ul. Pasteura 1, 02-093 Warsaw, Poland.
Chemosphere. 2016 Feb;144:1216-23. doi: 10.1016/j.chemosphere.2015.09.079. Epub 2015 Oct 23.
The paper presents both "good" and "bad" results obtained during speciation analysis of thallium in plant tissues of a hyperaccumulator of this metal. The object was white mustard - Sinapis alba L. In this plant there were found traces of trivalent thallium. The crucial point of this study (especially in the case of so unstable thallium form as Tl(III)) was to prove that the presence of Tl(III) was not caused by the procedure of sample preparation itself, and that the whole analytical method provides reliable results. Choice of the method for conservation of the initial speciation, extraction with the highest efficiency and proving the correctness of the obtained data were the most difficult parts of the presented study. It was found that: both freezing and drying cause significant changes in the speciation of thallium; quantitative analysis could be performed only with fresh tissues of mustard plants; only short-term storage of an extract from fresh plant tissues is possible; the methodology is not the source of thallium (III); only the presence of DTPA can greatly limit the reduction of TI(III) to TI(I) (up to 1-3%); the UV irradiation results in disintegration of TI(III)DTPA in the presence of plant matrix (reduction up to 90%).
该论文展示了在对一种该金属超富集植物的植物组织进行铊形态分析过程中获得的“好”与“坏”的结果。研究对象是白芥——Sinapis alba L.。在这种植物中发现了痕量三价铊。本研究的关键之处（尤其是对于像Tl(III)这样不稳定的铊形态而言）在于证明Tl(III)的存在并非由样品制备过程本身导致，且整个分析方法能提供可靠结果。选择用于保留初始形态的方法、进行最高效的萃取以及证明所获数据的正确性是本研究所面临的最困难部分。研究发现：冷冻和干燥都会导致铊形态发生显著变化；只能对芥菜植物的新鲜组织进行定量分析；新鲜植物组织提取物只能短期保存；该方法不是铊（III）的来源；只有二乙三胺五乙酸（DTPA）的存在能极大限制Tl(III)还原为Tl(I)（高达1 - 3%）；在植物基质存在的情况下，紫外线照射会导致Tl(III) - DTPA分解（还原高达90%）。
