Publications by authors named "Susana Cuello Nunez"

Reference materials (RMs) are increasingly needed to support number-based characterisation of nanomaterials (NM) in a regulatory context for the purpose of method development, validation and measurement quality control. To date, RMs for number concentration in suspension with a directly assigned value that is SI traceable have been rather scarce, being the LGCQC5050 the only material commercialised so far. This could be attributed to the limited availability of metrologically validated measurement methods and stability challenges associated with long-term storage of NM suspensions.

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Article Synopsis
  • A novel methodology combining asymmetrical flow field-flow fractionation (AF4) with ICP-MS and size fraction-targeted isotope dilution analysis (IDA) has been developed to measure nanoscale silica (SiO) mass fractions.
  • The approach involved synthesizing and characterizing Si-enriched SiO nanoparticles for use as internal standards in double and single IDA analyses, achieving measurement uncertainties of 4% and 8% in different matrices.
  • The method demonstrated high accuracy with a recovery rate of 95.6% in food samples, and results from IDA correlated well with those from external calibration, indicating effectiveness in characterizing nanoscale silica.
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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.

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Exchangeable copper (CuEXC), mainly comprised copper (Cu) bound to albumin, has been proposed as a specific marker of Cu overload in Wilson's disease (WD). To the author's knowledge, there are no methods capable of determining reliably CuEXC to meet the requirements and challenges faced by a clinical trial. The present work describes a novel speciation strategy for the determination of the main Cu-species in human serum by anion-exchange high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS).

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Background: Safe and rational development of nanomaterials for clinical translation requires the assessment of potential biocompatibility. Autophagy, a critical homeostatic pathway intrinsically linked to cellular health and inflammation, has been shown to be affected by nanomaterials. It is, therefore, important to be able to assess possible interactions of nanomaterials with autophagic processes.

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A method based on asymmetric flow field-flow fractionation (AF4) coupled to ultraviolet-visible (UV-vis) spectroscopy and inductively coupled plasma mass spectrometry (ICP-MS) has been developed for silver nanoparticles (Ag NPs) detection and quantification in bivalve molluscs. Samples were pre-treated using a conventional enzymatic (pancreatin and lipase) hydrolysis procedure (37 °C, 12 h). AF4 was performed using a regenerated cellulose (RC) membrane (10 kDa, 350 μm spacer) and aqueous 5 mM Tris-HCl pH = 7.

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Article Synopsis
  • The InNanoPart project was created to improve measurement techniques for high-value nanoparticles, aiming to enhance manufacturing control and quality assurance.
  • The paper showcases advancements in measuring nanoparticle concentration in liquids using cutting-edge methods like small angle X-ray scattering (SAXS) and single particle inductively coupled plasma mass spectrometry (spICPMS).
  • It also validates several laboratory techniques for analyzing nanoparticles, including particle tracking analysis (PTA) and dynamic light scattering (DLS), focusing on spherical gold nanoparticles ranging from 10 nm to 100 nm.
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Fractionation data for cadmium in tobacco products, as obtained by sequential leaching of cadmium species with ICP-MS/MS analysis, and separately by X-ray absorption near edge structure (XANES) are presented here for the first time. The total amount of cadmium found in 3R4F cigarette cut tobacco was 1526 ± 42 μg kg, of which 5% was found in the smoke under ISO smoking conditions. XANES analysis showed that Cd in tobacco, cigarette smoke and ash was present in the + 2 oxidation state.

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A novel strategy for the absolute quantification of selenium (Se) included in selenoprotein P (SEPP1), an important biomarker for human nutrition and disease, including diabetes and cancer, is presented here for the first time. It is based on the use of species-specific double isotope dilution mass spectrometry (SSIDA) in combination with HPLC-ICP-MS/MS for the determination of protein bound Se down to the peptide level in a complex plasma matrix with a total content of Se of 105.5 μg kg(-1).

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