CERTIFICATION REPORT: The certification of equivalent diameters of silica nanoparticles in aqueous solution: ERM®-FD101b

This report describes the production of ERM®-FD101b, silica nanoparticles suspended in an aqueous solution, certified for different equivalent particle diameters. The material was produced following ISO Guide 34:2009. The certified reference material (CRM) was produced by the Directorate F - Health, Consumers and Reference Materials of the European Commission’s Joint Research Centre (JRC) in Geel (Belgium). The CRM was produced from a diluted and pH adjusted commercial colloidal silica slurry. Between unit-homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. The minimum sample intake for the different methods was determined from the results and information provided by the laboratories that participated in the interlaboratory comparison (ILC) exercises of the characterisation study. The material was characterised for several equivalent particle diameters based on an interlaboratory comparison amongst laboratories of demonstrated competence and adhering to ISO/IEC 17025. Technically invalid results were removed but no outlier was eliminated on statistical grounds only. Uncertainties of the certified values were calculated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainty contributions related to possible inhomogeneity and instability and to characterisation. The material is intended for quality control and assessment of method performance. The method-defined certified values are regarded as reliable estimates of the true values and ERM-FD101b can therefore be used for calibration purposes. The CRM is available in 10 mL pre-scored amber glass ampoules each containing about 9 mL of suspension. The CRM was accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium.JRC.F.6-Reference Material

CERTIFICATION REPORT: The certification of electrophoretic mobility/zeta potential of silica particles in aqueous solution: ERM-FD306/SRM 1993

This report describes the production of ERM-FD306/SRM 1993, silica particles suspended in a borate buffer, certified for electrophoretic mobility and zeta potential by electrophoretic light scattering (ELS). This material was produced following ISO 17034:2016 and is certified in accordance with ISO Guide 35:2017. The certified reference material (CRM) was jointly produced by the Directorate F - Health, Consumers and Reference Materials of the European Commission’s Joint Research Centre (JRC) in Geel (Belgium) and the US National Institute of Standards and Technology (NIST), Gaithersburg (USA). The CRM was produced from a buffer-modified and diluted commercial colloidal silica slurry. Between-ampoule homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2017. The minimum sample intake for the ELS method was determined from the results and information provided by the laboratories that participated in the interlaboratory comparison (ILC) exercise. The material was characterised by an interlaboratory comparison between laboratories of demonstrated competence and adhering to ISO/IEC 17025. Technically invalid results were removed but no outlier was eliminated solely on statistical grounds. Uncertainties of the certified values were calculated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties related to possible inhomogeneity, instability and characterisation. The material is intended for quality control and assessment of method performance. The method-defined certified values are regarded as reliable estimates of the true values and ERM-FD306/SRM 1993 can therefore be used for calibration purposes. The CRM is available in 25 mL pre-scored amber glass ampoules each containing approximately 25 mL of suspension.JRC.F.6-Reference Material

CERTIFICATION REPORT The certification of electrophoretic mobility/zeta potential of silica particles in aqueous solution: ERM-FD305/SRM 1992

This report describes the production of ERM-FD305/SRM 1992, silica particles suspended in a borate buffer, certified for electrophoretic mobility and zeta potential by electrophoretic light scattering (ELS). This material was produced following ISO 17034:2016 and is certified in accordance with ISO Guide 35:2017. The certified reference material (CRM) was jointly produced by the Directorate F - Health, Consumers and Reference Materials of the European Commission’s Joint Research Centre (JRC) in Geel (Belgium) and the US National Institute of Standards and Technology (NIST), Gaithersburg (USA). The CRM was produced from a buffer-modified and diluted commercial colloidal silica slurry. Between-ampoule homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2017. The minimum sample intake for the ELS method was determined from the results and information provided by the laboratories that participated in the interlaboratory comparison (ILC) exercise. The material was characterised by an interlaboratory comparison between laboratories of demonstrated competence and adhering to ISO/IEC 17025. Technically invalid results were removed but no outlier was eliminated solely on statistical grounds. Uncertainties of the certified values were calculated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties related to possible inhomogeneity, instability and characterisation. The material is intended for quality control and assessment of method performance. The CRM is available in 5 mL pre-scored amber glass ampoules each containing approximately 5 mL of suspension.JRC.F.6-Reference Material

Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanoparticles

We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles

Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanoparticles

We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles

Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanoparticles

We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles

Optimisation des latex magnétiques utilisés dans les biotechnologies

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Development and Validation of Optical Methods for Zeta Potential Determination of Silica and Polystyrene Particles in Aqueous Suspensions

Zeta potential is frequently used to examine the colloidal stability of particles and macromolecules in liquids. Recently, it has been suggested that zeta potential can also play an important role for grouping and read-across of nanoforms in a regulatory context. Although the measurement of zeta potential is well established, only little information is reported on key metrological principles such as validation and measurement uncertainties. This contribution presents the results of an in-house validation of the commonly used electrophoretic light scattering (ELS) and the relatively new particle tracking analysis (PTA) methods. The performance characteristics were assessed by analyzing silica and polystyrene reference materials. The ELS and PTA methods are robust and have particle mass working ranges of 0.003 mg/kg to 30 g/kg and 0.03 mg/kg to 1.5 mg/kg, respectively. Despite different measurement principles, both methods exhibit similar uncertainties for repeatability (2%), intermediate precision (3%) and trueness (4%). These results confirm that the developed methods can accurately measure the zeta potential of silica and polystyrene particles and can be transferred to other laboratories that analyze similar types of samples. If direct implementation is impossible, the elaborated methodologies may serve as a guide to help laboratories validating their own methods

Validation of a Homogeneous Incremental Centrifugal Liquid Sedimentation Method for Size Analysis of Silica (Nano)particles

Silica nanoparticles display many unique physicochemical properties that make them desirable for use in awide variety of consumer products and compositematerials. Accurately measuring the size of these nanoparticles is important for achieving the desired nanoscale functionality of the final product and for regulatory compliances. This study covers the validation of a centrifugal liquid sedimentation method for accurate measurement of the Stokes diameter of silica particles with a near-spherical shape and dimensions in the nanometer and sub-nanometer scale range. The validated method provided unbiased results in the range of 50 nm to 200 nm, with a lower limit of detection of 20 nm. The relative standard uncertainties for precision, quantified in terms of repeatability and day-to-day variation, ranged from 0.2% to 1.0% and from <0.1% to 0.5%, respectively. The standard uncertainty for trueness was assessed at 4.6%. Within its working range, the method was found robust with respect to the type of cuvette, light factor, operator, and for defining the meniscus of the sample suspension. Finally, a relative expanded measurement uncertainty of 10% confirmed the satisfactory performance of the method.JRC.F.6-Reference Material