Silver nanoparticles (AgNPs) exhibit many unique properties which are increasingly leading to their application in many areas of technology including microelectronics, pharmaceuticals, food packaging and other consumer products. In response to this proliferation of silver nanoparticles there has been a growth in public and regulatory concern [1, 2] which is driving the need to identify suitable, robust techniques to detect and quantify AgNPs dispersed in environmental and/or complex matrices. The analysis of NPs for environmental/health applications is not a trivial task since, besides the determination of their concentration, it may be necessary to determine other properties (i.e. diameter, volume, area, mass, agglomeration and aggregation state, surface charge, elemental composition) that might play a role in NPs fate [3]. The current lack of validated analytical methods for NPs has prompted this work which has the final aim of setting up an experimental strategy to detect, size characterize and quantify AgNPs contained in consumer products. To pursue this objective a pool of analytical techniques (Asymmetrical and Centrifugal Field flow fractionation – AF4 and SdFFF, Differential Centrifugal Sedimentation-DCS, DLS, TEM, ICP-MS) were used to: i) 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) compare the relative performance of the different methods when separating polydisperse mixtures of AgNP of different sizes; iii) obtaining measurement data suitable for conversion into particle number-size distributions. In particular, this last point is an urgent and important task for the application of the definition of nanomaterial proposed by the European Commission, which is currently being implemented in the sectorial EU legislation [3-5]. The results will be discussed in the light of possible aggregation state, size resolution, analysis repeatability, signal quantification and quantitative recoveries.
A critical experimental evaluation of AF4, SdFFF, DCS and DLS for detection, sizing and quantification of silver nanoparticles
CONTADO, Catia
2014
Abstract
Silver nanoparticles (AgNPs) exhibit many unique properties which are increasingly leading to their application in many areas of technology including microelectronics, pharmaceuticals, food packaging and other consumer products. In response to this proliferation of silver nanoparticles there has been a growth in public and regulatory concern [1, 2] which is driving the need to identify suitable, robust techniques to detect and quantify AgNPs dispersed in environmental and/or complex matrices. The analysis of NPs for environmental/health applications is not a trivial task since, besides the determination of their concentration, it may be necessary to determine other properties (i.e. diameter, volume, area, mass, agglomeration and aggregation state, surface charge, elemental composition) that might play a role in NPs fate [3]. The current lack of validated analytical methods for NPs has prompted this work which has the final aim of setting up an experimental strategy to detect, size characterize and quantify AgNPs contained in consumer products. To pursue this objective a pool of analytical techniques (Asymmetrical and Centrifugal Field flow fractionation – AF4 and SdFFF, Differential Centrifugal Sedimentation-DCS, DLS, TEM, ICP-MS) were used to: i) 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) compare the relative performance of the different methods when separating polydisperse mixtures of AgNP of different sizes; iii) obtaining measurement data suitable for conversion into particle number-size distributions. In particular, this last point is an urgent and important task for the application of the definition of nanomaterial proposed by the European Commission, which is currently being implemented in the sectorial EU legislation [3-5]. The results will be 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.
