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

Improving the accuracy of single particle ICP-MS analyses of Au and Ag nanoparticles

Nanoteknologian nopean kehittymisen seurauksena nanomateriaaleja (NM) hyödynnetään lähes kaikilla toiminta-aloilla ja tuotekategorioissa, joka on herättänyt huolta mahdollisista ympäristö- ja terveysriskeistä. NM:en realistinen riskinarviointi vaatii monimutkaisille matriiseille soveltuvia kehittyneitä analyysitekniikoita, johon yksittäispartikkeli induktiivisesti kytketty plasma massaspektroskopia (SP-ICP-MS) on varteenotettava vaihtoehto. Joitakin jäljellä olevia haasteita on kuitenkin vielä ratkaistava tulosten tarkkuuden parantamiseksi. Tämä väitöskirja tarjoaa erilaisia ratkaisuja Au ja Ag nanopartikkeleiden (NP) määrityksen tarkkuuden parantamiseksi SP-ICP-MS:lla. Kirjallisuuskatsauksessa kuvataan SP-ICP-MS tekniikan perusteita ja olemassa olevia sovelluksia. Eräitä tekniikan jäljellä olevia haasteita ja käytettyjä ratkaisukeinoja käydään läpi. Kokeellisessa osuudessa kuvataan alkuperäisissä julkaisuissa esitetyt keinot NP:en määrityksen tarkkuuden parantamiseksi. Ensiksi tilastollista koesuunnittelua hyödynnettiin olosuhteiden optimoinnissa kullan SP-ICP-MS mittauksia varten, joka johti herkkyyden huomattavaan parantumiseen. Saavutettu 15 %:n lasku nanopartikkeleiden koon määritysrajassa mahdollisti tarkemman Au NP:en havainnoinnin ja määrittämisen. Seuraavaksi kehitettiin yksinkertainen näytteen esikäsittelymenetelmä liuenneen hopean poistamiseen käyttäen kiinteäfaasiuutto (SPE) materiaaleja, joka mahdollisti tarkemman Ag NP:n määrittämisen. Lopuksi esiteltiin näytteen esikäsittelymenetelmä liuenneen hopean poistamiseen hyödyntäen funktionaalisia 3D tulostettuja sieppareita. 3D tulostus mahdollisti tehokkaan SPE materiaalin yhdistämisen huokoiseen 3D sieppariin, joka mahdollisti tehokkaan liuennen hopean poistamisen säilyttäen samalla näytteen alkuperäiset Ag NP:en ominaisuudet. Tämän seurauksena Ag NP:n koon ja konsentraatiomäärityksen tarkkuutta saatiin huomattavasti parannettua.The remarkable advancements of nanotechnology have incorporated nanomaterials (NMs) in almost all fields of activity and product categories, which has raised concerns about the potential environmental and human health risks. The realistic risk assessment of NMs requires advanced analytical techniques suitable even for complex sample matrices, for which single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) is an efficient alternative. However, some remaining challenges still need to be addressed to improve the accuracy of the results. This thesis offers different approaches for improving the accuracy of the SP-ICP-MS analyses of Au and Ag nanoparticles (NPs). The literature review describes the fundamentals and a few of the existing applications of the SP-ICP-MS technique. Some of the remaining challenges of this technique and the existing procedures used to overcome these issues are discussed. The experimental section presents the different approaches used in the original papers to improve the accuracy of NP characterization and quantification. First, the optimization of instrumental conditions for SP-ICP-MS measurements of gold was carried out using a design of experiments (DoE) approach, significantly enhancing the instrument sensitivity. The 15% reduction in the NP size limit of detection allowed more accurate detection and determination of the Au NPs. This was followed by the development of a simple sample pretreatment procedure using solid phase extraction (SPE) materials for dissolved silver (AgD) removal, thus allowing a more accurate determination of Ag NPs. Finally, a novel sample pretreatment method was presented using functional 3D printed scavengers for AgD removal. 3D printing enabled the incorporation of an efficient SPE material into highly porous 3D scavengers, allowing efficient removal of AgD while preserving the original Ag NP properties of the sample. Thus, more highly accurate sizing and counting of Ag NPs was achieved

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.peerReviewe

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