{"status":"OK","msg":"Details loaded!","presentation":{"id":102,"title":"TOTAL REFLECTION X-RAY SPECTROMETRY FOR MONITORING SILVER NANOPARTICLES IN ENVIRONMENTAL STUDIES","abstract":"Nowadays, the production and use of engineered nanomaterials (ENMs) for industrial applications has been grown. Among the different types of ENMs, metallic nanoparticles have been increasingly used, being silver nanoparticles (AgNPs) one of the most utilised due to their antibacterial properties. Because of the expansion of their fabrication, the release of these emerging pollutants into the environment has enhanced, especially in soils that are the main fate. Consequently, vegetables that grow in agricultural soils can absorb AgNPs suspended in soil fluids. Therefore, it is important to develop and improve analytical techniques in order to monitor these particles in the environment. With this purpose, we tested the possibilities of using total X-ray reflection spectrometry (TXRF) to monitor the silver content in soil adsorption kinetic studies and in the evaluation of AgNPs bioavailability to vegetal samples.\r\nFor soil adsorption studies, an amount of soil was put in contact with a volume of a solution containing the analyte (AgNPs). Then, the analyte in the supernatant was monitored over the time, allowing its adsorption kinetics study on the soil. For TXRF analysis of soil extracts, it was found that using a deposition volume of 10 \u03bcL and a measuring time of 2000 s the limit of detection of Ag (Ag-K\u03b1 detection) was around 40 \u03bcg\u00b7L-1, which was suitable to carry out this kind of lab-controlled studies. TXRF results were compared with those obtained by inductively coupled plasma optic emission spectrometry (ICP-OES) and good agreement was found. \r\nFurthermore, we explored the possibilities to analyse directly the Ag adsorbed in the soil after performing the kinetic studies. In this case, the limit of detection for Ag using 50 mg of soil was around 1.5 mg\u00b7Kg-1. Results obtained using such approach was compared with those obtained after acidic microwave digestion of the soil and similar values were obtained. \r\nThe evaluation of the transference of AgNPs to crops was performed through hydroponic experiments. These experiments consist on growing the plant in a hydroponic solution that contains the analyte. In this study, lettuces were grown in hydroponic media containing AgNPs or ionic silver (Ag+) during 9 days in lab-controlled conditions. After 9 days, an acid microwave digestion of the vegetal samples (roots and leaves) was done. The TXRF analysis of vegetal digests was performed using the same instrumental conditions as the soil kinetics studies. In the results obtained, the uptake AgNPs or Ag+ by roots was confirmed but not translocation to leaves. Results obtained were also compared with those obtained by ICP-OES.\r\nIn conclusion, TXRF spectrometry can be considered a faster, simpler and cost-effective tool for AgNPs determination in soil adsorption studies as well as in investigations of their exposure to vegetables. It uses small sample volumes and it provides simultaneous multi-elemental information that can be useful to improve the understanding of the controlling factors on Ag mobility and bioavailability. \r\n","keywords":"TXRF; silver; nanoparticles","status":"active","sarx_st":"accepted","user_id":198,"created_at":"2016-07-11 13:14:38","updated_at":"2016-08-20 12:24:17","filename":"Torrent_SARX2016_POSTER_AgNanoparticles_Abstract.docx","mode":"oral","sarx_code":"15_O-XRF","poster_group":null,"file":"58ffac81a5da6f9bcece7c238060fa3a.docx","author":"Ignasi QUERALT","affiliation":"Dr. \/<\/b> Inst. of Environmental Assessment and Water Research - CSIC \/<\/b> Spain","user":{"id":198,"name":"Ignasi QUERALT","degree":"Dr.","email":"ignasi.queralt@idaea.csic.es","username":"ignasi.queralt@idaea.csic.es","confirmed":1,"confirmation_code":null,"created_at":"2016-07-08 07:12:53","updated_at":"2016-07-11 13:28:51","sarx":1,"affiliation":"Inst. of Environmental Assessment and Water Research - CSIC","address":"Jordi Girona St., 18-26","zipcode":"08020","state":"Catalonia","phone":"+34.934006100","fax":null,"city":"Barcelona","country":"Spain","status":"active","is_admin":0,"category":"professor","school":1,"icdd":0}}}