Interacció de nanopartícules metàl.liques de plata amb el medi ambient: anàlisi i caracterització mitjançant tècniques d'espectroscòpia atòmica (IPC-OES i ICP-MS)

Abstract

Nanoparticles’ field has experienced an exponential growth in last years due to the need of nanotechnology in everyday items, which are further miniaturized day by day. This high consumption of nanoparticles has risen a concern about their potential impact on the environment and life, very few studies have been portrayed over these possible harms. Some very spreadly used nanoparticles, specially in medicine, are silver nanoparticles, which are used as antimicrobials in burnt patients. The objective of the present study is to analyze the behaviour of silver nanoparticles in the environment, in plants (lettuce) to be more precise, to determine the amount of nanoparticles absorbed by the plant and the amount of it displaced by the roots to the leafs. It’s also important to discover the factors that increase the nanoparticles absorbed by the roots and the ones that increase its displacement to the leafs. This is why one of the objectives established in this study is to improve the results obtained in previous ones, modifying different procedures. To accomplish these objectives several experiments have been performed with silver nanoparticle fortified crops, which were digested through two different systems depending on the experiment, enzymatic digestion and complete digestion. Once the samples were digested, they were analyzed with an ICP-OES and an ICP-MS in order to quantify the amount of silver captured by them. The presence of ionic silver and nanoparticles was also determined with the ICP-MS’ single particle mode. Once analyzed all samples, the results have shown that some of the changes applied to these have offered better values than the ones obtained in previous studies, some more effectives than others. The modification that has offered the best results has been magnetic stirring. It has also been possible to observe how plants absorb silver and displace it to its leafs. Furthermore, the presence of silver in the roots has been confirmed, but the presence of nanoparticles on the leafs has not been determined yet. Finally, more changes and experiments should be performed in order to improve the standard deviations of the results, as well as to manage some way of filtering the samples without losing most of the silver nanoparticles (AgNPs) to determine its presence in leafs through SP-ICP-MS technique