Special Issue "Analytic Techniques for Nano- and Microparticles Analysis"

A special issue of Separations (ISSN 2297-8739).

Deadline for manuscript submissions: closed (31 December 2018)

Special Issue Editors

Guest Editor
Dr. Katrin Löschner

National Food Institute, Technical University of Denmark
Website | E-Mail
Interests: detection and characterization of nanoparticles in food, feed and biological matrices; asymmetric flow field fractionation; inductively coupled plasma mass spectrometry in conventional and single particle mode; electron microscopy; targeted sample preparation
Guest Editor
Dr. Jana Navratilova

National Reserach Council fellow at U.S. Environmental Protection Agency, National Exposure Reasearch Laboratory
E-Mail
Interests: analysis of nanoparticles in complex samples; nanoparticle fate and behavior in various environments; exposure and risk assesment
Guest Editor
Dr. Stephan Wagner

Helmholtz Centre for Environmental Research - UFZ
Website | E-Mail
Interests: nanometrology; particle separation techniques; imaging techniques; natural nanoscale processes; environmental nanotechnology; microplastics

Special Issue Information

Dear Colleagues,

Nano- and microparticles play a crucial role as materials, e.g., in chemicals, food/feed, cosmetics, pharmaceuticals and plastics, or as contaminants in the environment, in organism or products. To develop particle-based materials with the desired properties for certain applications, and to assess their human and environmental risks, particle analysis is required. Additionally, there is a need for validated analytical methods for nano- and microparticles in the context of regulation. Particle analysis focuses predominantly on particle size, shape, composition and concentration. Particle separation can be performed for two reasons: 1) to separate particles with different properties (such as size); or 2) to separate particles from a matrix (gas, water or more complex matrices, such as environmental and biological samples or food/feed). In most cases, particle characterization in complex matrices requires a separation (e.g., by AF4, SEC, HDC) of the particles from the matrix prior to the actual analysis (e.g., by MALS, UV, ICP-MS).

This Special Issue invites contributions relating to all aspects of nano- and microparticle analysis including sample preparation strategies, instrumentation and applications.

Dr. Katrin Loeschner
Dr. Jana Navratilova
Dr. Stephan Wagner
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Separations is an international peer-reviewed open access quarterly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 350 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • field flow fractionation
  • size exclusion chromatography
  • hydrodynamic chromatography
  • hyphenation
  • single particle ICPMS
  • nanoparticles
  • microparticles
  • nanoplastics
  • microplastics
  • sample preparation

Published Papers (4 papers)

View options order results:
result details:
Displaying articles 1-4
Export citation of selected articles as:

Research

Open AccessFeature PaperArticle
Establishing SI-Traceability of Nanoparticle Size Values Measured with Line-Start Incremental Centrifugal Liquid Sedimentation
Separations 2019, 6(1), 15; https://doi.org/10.3390/separations6010015
Received: 21 December 2018 / Revised: 20 February 2019 / Accepted: 25 February 2019 / Published: 12 March 2019
PDF Full-text (2347 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Line-start incremental centrifugal liquid sedimentation (disc-CLS) is a powerful technique to determine particle size based on the principles of Stokes’ law. As most input quantities of the Stokes equation cannot be easily determined for typical instruments used for this method, an alternative method [...] Read more.
Line-start incremental centrifugal liquid sedimentation (disc-CLS) is a powerful technique to determine particle size based on the principles of Stokes’ law. As most input quantities of the Stokes equation cannot be easily determined for typical instruments used for this method, an alternative method which depends on calibrating the sedimentation time scale with reference particles has become common practice. Unfortunately, most of these calibration materials (calibrants) come with limited information regarding their metrological reliability (e.g., lack of measurement uncertainties and traceability statements, incomplete measurand definitions). As a consequence, routine particle size results obtained by disc-CLS are mostly only traceable to the calibrant used, and effective comparisons can only be made for those results originating from measurements performed with the same types of calibrants. In this study, we discuss the concept of metrological traceability and demonstrate that particle size results obtained by disc-CLS can be traceable to the ultimate metrological reference, i.e., the unit of length in the International System of Units (SI), the meter. Using the example of two colloidal silica certified reference materials, we describe how laboratories can realize metrological traceability to the SI by simplifying complex traceability networks. Full article
(This article belongs to the Special Issue Analytic Techniques for Nano- and Microparticles Analysis)
Figures

Figure 1

Open AccessFeature PaperArticle
Gold Nanoparticle Uptake in Tumor Cells: Quantification and Size Distribution by sp-ICPMS
Received: 31 October 2018 / Revised: 22 November 2018 / Accepted: 13 December 2018 / Published: 9 January 2019
PDF Full-text (1619 KB) | HTML Full-text | XML Full-text
Abstract
Gold nanoparticles (AuNPs) are increasingly studied for cancer treatment purposes, as they can potentially improve both control and efficiency of the treatment. Intensive research is conducted in vitro on rodent and human cell lines to objectify the gain of combining AuNPs with cancer [...] Read more.
Gold nanoparticles (AuNPs) are increasingly studied for cancer treatment purposes, as they can potentially improve both control and efficiency of the treatment. Intensive research is conducted in vitro on rodent and human cell lines to objectify the gain of combining AuNPs with cancer treatment and to understand their mechanisms of action. However, using nanoparticles in such studies requires thorough knowledge of their cellular uptake. In this study, we optimized single particle ICPMS (sp-ICPMS) analysis to qualify and quantify intracellular AuNP content after exposure of in vitro human breast cancer cell lines. To this aim, cells were treated with an alkaline digestion method with 5% TMAH, allowing the detection of gold with a yield of 97% on average. Results showed that under our experimental conditions, the AuNP size distribution appeared to be unchanged after internalization and that the uptake of particles depended on the cell line and on the exposure duration. Finally, the comparison of the particle numbers per cell with the estimates based on the gold masses showed excellent agreement, confirming the validity of the sp-ICPMS particle measurements in such complex samples. Full article
(This article belongs to the Special Issue Analytic Techniques for Nano- and Microparticles Analysis)
Figures

Figure 1

Open AccessArticle
Challenges in Determining the Size Distribution of Nanoparticles in Consumer Products by Asymmetric Flow Field-Flow Fractionation Coupled to Inductively Coupled Plasma-Mass Spectrometry: The Example of Al2O3, TiO2, and SiO2 Nanoparticles in Toothpaste
Separations 2018, 5(4), 56; https://doi.org/10.3390/separations5040056
Received: 31 October 2018 / Revised: 19 November 2018 / Accepted: 21 November 2018 / Published: 27 November 2018
Cited by 1 | PDF Full-text (3416 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
According to the current European regulation on cosmetics, any ingredient present as a nanomaterial should be indicated in the ingredient list. There is a need for analytical methods capable of determining the size of the relevant ingredients and thus assessing if these are [...] Read more.
According to the current European regulation on cosmetics, any ingredient present as a nanomaterial should be indicated in the ingredient list. There is a need for analytical methods capable of determining the size of the relevant ingredients and thus assessing if these are nanomaterials or not. An analytical method based on asymmetric flow field-flow fractionation (AF4) and inductively coupled plasma-mass spectrometry (ICP-MS) was developed to determine the size of particles present in a commercial toothpaste. Multi-angle light scattering (MALS) was used for on-line size determination. The number-based particle size distributions (PSDs) of the particles were retrieved upon mathematical conversion of the mass-based PSDs recovered from the AF4-ICP-MS fractograms. AF4-ICP-MS allowed to separate and detect Al2O3 and TiO2 particles in the toothpaste and to retrieve a correct TiO2 number-based PSD. The potential presence of particles in the lower size range of the Al2O3 mass-based PSD had a strong impact on sizing and nanomaterial classification upon conversion. AF4 coupled with ICP-MS and MALS was found to be a powerful approach for characterization of different particles in a multiple-particle system such as toothpaste. Confirmation of particle size by a secondary method such as single particle ICP-MS or hydrodynamic chromatography was crucial. Full article
(This article belongs to the Special Issue Analytic Techniques for Nano- and Microparticles Analysis)
Figures

Figure 1

Open AccessArticle
Characterization of the Natural Colloidal TiO2 Background in Soil
Separations 2018, 5(4), 50; https://doi.org/10.3390/separations5040050
Received: 27 August 2018 / Revised: 26 September 2018 / Accepted: 4 October 2018 / Published: 20 October 2018
PDF Full-text (3913 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
An increasing amount of TiO2 engineered nanoparticles (TNP) is released into soils and sediments, increasing the need for dedicated detection methods. Titanium is naturally present in soils at concentrations typically much higher than the estimated concentrations for TNP. Therefore, a precise knowledge [...] Read more.
An increasing amount of TiO2 engineered nanoparticles (TNP) is released into soils and sediments, increasing the need for dedicated detection methods. Titanium is naturally present in soils at concentrations typically much higher than the estimated concentrations for TNP. Therefore, a precise knowledge of this natural background, including the colloidal fraction, is required for developing adapted strategies for detecting TNP. In this study, we characterized the natural colloidal Ti-background by analyzing eight soils with different properties and origins. A combination of X-ray fluorescence analysis and ICP-OES was used for determining the silicate bound fraction, which was a minor fraction for all soils (0–32%). The colloidal fraction obtained by extracting colloids from soil prior to ICP-OES measurements ranged between 0.3% and 7%. Electron microscopy and hydrodynamic chromatography confirmed that Ti in the form of colloids or larger particles was mostly present as TiO2 minerals with a fraction smaller than 100 nm. The size distribution mode of the extracted colloids determined using hydrodynamic chromatography ranged between 80 and 120 nm. The chromatograms suggested a broad size distribution with a significant portion below 100 nm. In addition to these data, we also discuss possible implications of our findings for the method development for detecting TNP in soils. Full article
(This article belongs to the Special Issue Analytic Techniques for Nano- and Microparticles Analysis)
Figures

Graphical abstract

Separations EISSN 2297-8739 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top