Arena Valentina, Smecca Emanuele, Valastro Salvatore, Bongiorno Corrado, Fisicaro Giuseppe, Deretzis Ioannis, Spampinato Carlo, Mannino Giovanni, Dattilo Sandro, Scamporrino Andrea Antonino, Carroccio Sabrina Carola, La Magna Antonino, Alberti Alessandra
CNR-IMM, Zona Industriale Strada VIII n.5, 95121 Catania, Italy.
Dipartimento Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, Università Degli Studi di Messina, Viale F. Stagno d'Alcontres 31, 98166 Messina, Italy.
Nanomaterials (Basel). 2023 Apr 18;13(8):1397. doi: 10.3390/nano13081397.
The importance of lead analysis in environmental matrices becomes increasingly relevant due to the anthropogenic spread of toxic species in nature. Alongside the existing analytical methods to detect lead in a liquid environment, we propose a new dry approach for lead detection and measurement based on its capture from a liquid solution by a solid sponge and subsequent quantification based on X-ray analyses. The detection method exploits the relationship between the electronic density of the solid sponge, which depends on the captured lead, and the critical angle for total reflection of the X-rays. For this purpose, gig-lox TiO layers, grown by modified sputtering physical deposition, were implemented for their branched multi-porosity spongy structure that is ideal for capturing lead atoms or other metallic ionic species in a liquid environment. The gig-lox TiO layers grown on glass substrates were soaked into aqueous solutions containing different concentrations of Pb, dried after soaking, and finally probed through X-ray reflectivity analyses. It has been found that lead atoms are chemisorbed onto the many available surfaces within the gig-lox TiO sponge by establishing stable oxygen bonding. The infiltration of lead into the structure causes an increase in the overall electronic density of the layer and, thus, an increment of its critical angle. Based on the established linear relationship between the amount of lead adsorbed and the augmented critical angle, a standardized quantitative procedure to detect Pb is proposed. The method can be, in principle, applied to other capturing spongy oxides and toxic species.
由于有毒物种在自然界中的人为扩散，环境基质中铅分析的重要性日益凸显。除了现有的在液体环境中检测铅的分析方法外，我们还提出了一种新的干式铅检测和测量方法，该方法基于固体海绵从液体溶液中捕获铅，随后基于X射线分析进行定量。该检测方法利用了固体海绵的电子密度（取决于捕获的铅）与X射线全反射临界角之间的关系。为此，通过改进的溅射物理沉积生长的千兆lox TiO层因其分支多孔海绵结构而被采用，该结构非常适合在液体环境中捕获铅原子或其他金属离子物种。将生长在玻璃基板上的千兆lox TiO层浸泡在含有不同浓度Pb的水溶液中，浸泡后干燥，最后通过X射线反射率分析进行探测。研究发现，铅原子通过建立稳定的氧键化学吸附在千兆lox TiO海绵内的许多可用表面上。铅渗入结构会导致层的整体电子密度增加，从而使其临界角增大。基于所建立的吸附铅量与增大的临界角之间的线性关系，提出了一种标准化的检测Pb的定量程序。该方法原则上可应用于其他捕获海绵状氧化物和有毒物种。
