title: Suitability of analytical methods to measure solubility for the purpose of nanoregulation.
abstract: Solubility is an important physicochemical parameter in nanoregulation. If nanomaterial is completely soluble, then from a risk assessment point of view, its disposal can be treated much in the same way as "ordinary" chemicals, which will simplify testing and characterisation regimes. This review assesses potential techniques for the measurement of nanomaterial solubility and evaluates the performance against a set of analytical criteria (based on satisfying the requirements as governed by the cosmetic regulation as well as the need to quantify the concentration of free (hydrated) ions). Our findings show that no universal method exists. A complementary approach is thus recommended, to comprise an atomic spectrometry-based method in conjunction with an electrochemical (or colorimetric) method. This article shows that although some techniques are more commonly used than others, a huge research gap remains, related with the need to ensure data reliability.
authors.affiliation: a Surface and Nanoanalysis, National Physical Laboratory , Teddington , Middlesex , UK .
authors.forename: Ratna
authors.initials: R
authors.lastname: Tantra
authors.affiliation: b Toxicology and Bioassays, RIKILT - Wageningen University & Research Center , Wageningen , The Netherlands .
authors.forename: Hans
authors.initials: H
authors.lastname: Bouwmeester
authors.affiliation: c Group of Analytical Spectroscopy and Sensors (GEAS), Institute of Environmental Sciences (IUCA), Universidad de Zaragoza , Zaragoza , Spain .
authors.forename: Eduardo
authors.initials: E
authors.lastname: Bolea
authors.affiliation: d Departament de Química and AGROTECNIO , Universitat de Lleida , Lleida , Catalonia , Spain .
authors.forename: Carlos
authors.initials: C
authors.lastname: Rey-Castro
authors.affiliation: d Departament de Química and AGROTECNIO , Universitat de Lleida , Lleida , Catalonia , Spain .
authors.forename: Calin A
authors.initials: CA
authors.lastname: David
authors.affiliation: e Department of Pharmacy, Namur Nanosafety Centre, Namur Medicine & Drug Innovation Center (NAMEDIC) , University of Namur (UNamur) , Namur , Belgium , and.|f Namur Research Institute for Life Sciences (NARILIS), University of Namur (UNamur) , Namur , Belgium.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Dogné
authors.affiliation: a Surface and Nanoanalysis, National Physical Laboratory , Teddington , Middlesex , UK .
authors.forename: John
authors.initials: J
authors.lastname: Jarman
authors.affiliation: b Toxicology and Bioassays, RIKILT - Wageningen University & Research Center , Wageningen , The Netherlands .
authors.forename: Francisco
authors.initials: F
authors.lastname: Laborda
authors.affiliation: e Department of Pharmacy, Namur Nanosafety Centre, Namur Medicine & Drug Innovation Center (NAMEDIC) , University of Namur (UNamur) , Namur , Belgium , and.|f Namur Research Institute for Life Sciences (NARILIS), University of Namur (UNamur) , Namur , Belgium.
authors.forename: Julie
authors.initials: J
authors.lastname: Laloy
authors.affiliation: a Surface and Nanoanalysis, National Physical Laboratory , Teddington , Middlesex , UK .
authors.forename: Kenneth N
authors.initials: KN
authors.lastname: Robinson
authors.affiliation: c Group of Analytical Spectroscopy and Sensors (GEAS), Institute of Environmental Sciences (IUCA), Universidad de Zaragoza , Zaragoza , Spain .
authors.forename: Anna K
authors.initials: AK
authors.lastname: Undas
authors.affiliation: c Group of Analytical Spectroscopy and Sensors (GEAS), Institute of Environmental Sciences (IUCA), Universidad de Zaragoza , Zaragoza , Spain .
authors.forename: Meike
authors.initials: M
authors.lastname: van der Zande
mesh_terms: D053000:Analytic Sample Preparation Methods / Q000379:methods; D002623:Chemistry Techniques, Analytical / Q000379:methods* / Q000592:standards*; D003124:Colorimetry / Q000379:methods; D055664:Electrochemical Techniques / Q000379:methods; D008962:Models, Theoretical; D049329:Nanostructures / Q000737:chemistry*; D015203:Reproducibility of Results; D012995:Solubility; D013054:Spectrophotometry, Atomic
keywords: Nanomaterials; regulation; solubility