Silver nanoparticles (AgNPs) have important physico-chemical properties that have them brought to be used in several technological ambits such as microelectronics, medical imaging, pharmaceutical, foods, and consumer products. As a consequence of their widespread applications, both scientific community and industry are developing forefront research topics applications based on AgNPs. On a parallel plane, in order to answer to the public and regulatory concern, referred the potential risks the NPs may pose to the environment and to human health, the scientific community is working to find the most suitable and robust techniques to detect and quantify AgNPs dispersed in environmental and/or complex matrices. The analysis of NPs is not a trivial task since besides the determination of their concentration, it is necessary to determine several other metrics such as diameter, volume, area, mass, agglomeration and aggregation state, surface charge, elemental composition, because these parameters play a crucial role in the NPs fate. The scarcity of validated analytical methods for NPs has inspired this work, which has the final aim of setting up an experimental strategy to detect, size characterize and quantify NPs contained in consumer products. To pursue this scope, a pool of analytical techniques (Asymmetrical and Centrifugal Field flow fractionation – AsF4 and SdFFF, Differential Centrifugal Sedimentation-DCS, DLS, TEM, ICP-MS) were used i) to obtain complementary size information about AgNP suspensions in the size range 20-100 nm, by taking advantage of the different physical principles on which the techniques are based; ii) to compare the separation results with the awareness that these techniques are all operating in wet conditions, as to produce data which could be interesting from a toxicological point of view; iii) to achieve quantitative particle size distribution analysis. This last point is an urgent and important task in the European regulatory framework, in particular in relation to commercial products. The results are discussed in the light of possible aggregation state, size resolution, analysis repeatability, signal quantification and quantitative recoveries.
Detection, sizing and quantification of silver nanoparticles: a critical experimental evaluation of some key methods
CONTADO, Catia;
2014
Abstract
Silver nanoparticles (AgNPs) have important physico-chemical properties that have them brought to be used in several technological ambits such as microelectronics, medical imaging, pharmaceutical, foods, and consumer products. As a consequence of their widespread applications, both scientific community and industry are developing forefront research topics applications based on AgNPs. On a parallel plane, in order to answer to the public and regulatory concern, referred the potential risks the NPs may pose to the environment and to human health, the scientific community is working to find the most suitable and robust techniques to detect and quantify AgNPs dispersed in environmental and/or complex matrices. The analysis of NPs is not a trivial task since besides the determination of their concentration, it is necessary to determine several other metrics such as diameter, volume, area, mass, agglomeration and aggregation state, surface charge, elemental composition, because these parameters play a crucial role in the NPs fate. The scarcity of validated analytical methods for NPs has inspired this work, which has the final aim of setting up an experimental strategy to detect, size characterize and quantify NPs contained in consumer products. To pursue this scope, a pool of analytical techniques (Asymmetrical and Centrifugal Field flow fractionation – AsF4 and SdFFF, Differential Centrifugal Sedimentation-DCS, DLS, TEM, ICP-MS) were used i) to obtain complementary size information about AgNP suspensions in the size range 20-100 nm, by taking advantage of the different physical principles on which the techniques are based; ii) to compare the separation results with the awareness that these techniques are all operating in wet conditions, as to produce data which could be interesting from a toxicological point of view; iii) to achieve quantitative particle size distribution analysis. This last point is an urgent and important task in the European regulatory framework, in particular in relation to commercial products. The results are discussed in the light of possible aggregation state, size resolution, analysis repeatability, signal quantification and quantitative recoveries.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
