Nanomaterials in consumer products: a challenging analytical problem

Many products used in everyday life are made with the assistance of nanotechnologies. Cosmetic, pharmaceuticals, sunscreen, powdered food are only few examples of end products containing nano-sized particles (NPs), generally added to improve the product quality. To evaluate correctly benefits vs. risks of engineered nanomaterials and consequently to legislate in favor of consumer's protection, it is necessary to know the hazards connected with the exposure levels. This information implies transversal studies and a number of different competences. On analytical point of view the identification, quantification and characterization of NPs in food matrices and in cosmetic or personal care products pose significant challenges, because NPs are usually present at low concentration levels and the matrices, in which they are dispersed, are complexes and often incompatible with analytical instruments that would be required for their detection and characterization. This paper focused on some analytical techniques suitable for the detection, characterization and quantification of NPs in food and cosmetics products, reports their recent application in characterizing specific metal and metal-oxide NPs in these two important industrial and market sectors. The need of a characterization of the NPs as much as possible complete, matching complementary information about different metrics, possible achieved through validate procedures, is what clearly emerges from this research. More work should be done to produce standardized materials and to set-up methodologies to determine number-based size distributions and to get quantitative date about the NPs in such a complex matrices

Nano- and micro-particles in food and consumer products: the role of the Field Flow Fractionation techniques in their characterization

Nanomaterials (NMs) cover a broad range of materials of different chemical composition. Because of their diverse properties, they are used in a wide range of applications and products, such as cosmetic products (e.g. UV absorbers in sunscreens), food (enhanced flavour and texture, encapsulation of micronutrients), medical devices (diagnostics, drug delivery), medicinal products. The recent abundant use of NMs has placed, however, the accent on their potential risk, since nanoparticles, with their sizes between 1-100 nm, might interact with membrane cells of any living beings (plants, animals, humans). Consequently, legislators who are dealing with health and consumer protection have asked to the scientific community to implement or set-up new analytical methods able to detect and characterize the nanoparticles contained especially in food and consumer products to evaluate the risk on a solid definition of NMs. This work will illustrate, as the Field Flow Fractionation techniques (FFF), might be useful separation instruments to sort complex samples and to determine the average sizes and the particle size distribution of nano- and micro-particles. FFF techniques are often coupled online with a series of detectors such as UV-vis, refractive index, fluorescence, scattering detectors (DLS or MALS), ICP-MS, ICP-OES, GFAAS, whose choice depends on the practical application. Examples of SiO2, silver, and ZnO separations will be presented in the light of the characterization suggested by the European Commission

Field flow fractionation techniques to explore the “nano-world”

Field flow fractionation (FFF) techniques are used to successfully characterize several nanomaterials by sizing nano-entities and producing information about the aggregation/agglomeration state of nanoparticles. By coupling FFF techniques to specific detectors, researchers can determine particle-size distributions (PSDs), expressed as mass-based or number-based PSDs. This review considers FFF applications in the food, biomedical, and environmental sectors, mostly drawn from the past 4 y. It thus underlines the prominent role of asymmetrical flow FFF within the FFF family. By concisely comparing FFF techniques with other techniques suitable for sizing nano-objects, the advantages and the disadvantages of these instruments become clear. A consideration of select recent publications illustrates the state of the art of some lesser-known FFF techniques and innovative instrumental set-ups

Field Flow Fractionation: tools for exploring the NanoWorld

The Field Flow Fractionation (FFF) techniques are powerful tools able to perform fast, gentle and high resolution separations of any particulate matter from 1 nm up to 100 µm in a liquid medium. The separation occurs inside an open flow channel without the presence of any packing or stationary phase inside, thanks to the action of a field force applied perpendicularly to it. The different force field (liquid flows, centrifugal forces, temperature gradients or gravity fields), determines the FFF method. FFF are nowadays particularly useful for the characterization of nano-entities, such the nanoparticles (NPs) added in many everyday products. Flow-FFF, often coupled on-line with specific element detectors, such as ICP-MS, or the centrifugal FFF, are the most common methods used to sort and size NPs. Size, along with shape, morphology and many other physicochemical parameters are , in fact, the principal characteristics, which has to be determined to evaluate the health or/and environmental effects caused by the NPs. This presentation will present an overview of the most relevant information, which can be achieved thanks to the FFF methods in the field of nanotechnologies

A new strategy for pressed powder eye shadows analysis: Allergenic metal ions content and particle size distribution of the insoluble matter

Before being placed on the market, all cosmetics undergo a battery of safety tests to safeguard consumers from possible side-effects. Despite these controls, sometimes cosmetics do have side effects: some are immediate and visible reactions, others may appear with prolonged use. Among decorative cosmetics, eye shadows deserve particular attention because they are applied in the peri-ocular area, the area around the eyes where the facial skin thinnest; here the risk of percutaneous absorption of the pigments — and thus of toxic elements — is very high as is the risk of developing irritative and/or allergic skin reactions. In this work nine compact powder eye shadows — very inexpensive products sold in Italy and targeted to children and adults — were examined for the first time in order to i) determine the Ni, Co and Cr concentrations, ii) quantify the “water” soluble chromium and at the same time, iii) obtain the particle size distribution of the water-dispersible submicro-particles contained in all powders. In many cases, the Cr, Co and Ni concentrations, determined by Graphite Furnace Atomic Absorption Spectrometry (GF-AAS), were higher than 1 or 5 ppm (µg/g), i.e. the limits recommended in the scientific literature to minimize the risk of reaction in particularly sensitive subjects. In most cases, the concentration of Cr was higher than that of Ni and Co, up to a limit case of 150 mg/g. In this particular sample, the potential amount of Cr that could be released in ionic form was determined in sweat simulating solutions by GF-AAS and confirmed through a specific spectrofluorimetric method; the results indicated the presence of approximately 80-90 ppb (ng/g) of Cr3+. The water dispersible particles were isolated from the eye shadow powders through a simple solvent extraction procedure. The aqueous suspensions were then sorted through Sedimentation Field Flow Fractionation (SdFFF) and the particles sizes were calculated from experimental fractograms using theory. For the most part, the computed sizes were in the micron range, as confirmed by some SEM photographs taken on fractions collected during the separations. The SdFFF coupled off-line with the GFAAS enabled elemental characterization of pigment particles as a function of size.This finding reduces the concern that the ingredients of such makeup formulations may contain nanoparticles

The sedimentation field flow fractionation technique to study the effects on PLGA particles of secondary preparative parameters and aging

Biodegradable colloidal particles of PLGA (Poly(lactic-co-glycolic acid)) are excellent delivery carriers for drugs because they show high stability and high carrier capacity; they can feasibly incorporate both hydrophilic and hydrophobic substances, and offers various feasibly routes of administration. Several methods are currently employed to formulate PLGA particles with the smallest possible sizes and maximum stability for pharmaceutical applications In this work PLGA particles were prepared by nanoprecipitation and single emulsion (or solvent evaporation) methods in order to achieve particles stable in the long run, with appropriate dimensions for injectable uses (200-400 nm size range). Different concentrations of polymer and stabilizing (Pluronic® F68) were tested in order to identify the best conditions for making PLGA particles of suitable size, stable in time, that disperse themselves well in aqueous media, a key requirement for uses as vehicles to induce in vivo drug targeting, to be used as carriers for brain targeting drugs. The particles with the best characteristics for delivery system design were those formulated by nanoprecipitation with an organic/water phase ratio of 2/30, a polymer concentration of 25 mg/mL and a surfactant concentration of 0.83 mg/mL; their surface charge was reasonably negative (~ -27 mV) and the average size of the almost monodisperse population was roughly 250 nm. Particle characterization was accomplished by using SEM to check the morphology, calculating the surface charge through -potential measurements and determining the average sizes and particle size distributions (PSDs), the latter achieved by both PCS (photon correlation spectroscopy) and SdFFF (sedimentation field flow fractionation). SdFFF, the technique considered more reliable than PCS in describing the possible PSD modifications was used to investigate the effects three months of storage at 4 °C had on the lyophilized particles

Metodologia di frazionamento in campo-flusso per l'analisi di colloidi di rilevanza ambientale

Dottorato di ricerca in scienze chimiche. 8. ciclo. A.a. 1992-95. Relatore F. Dondi. Coordinatore V. CarassitiConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

AN ORCHESTRA OF ANALYTICAL TECHNIQUES TO INVESTIGATE EVERYDAY PRODUCTS

Many products of common use benefit of nanotechnologies. Cosmetic, sunscreen, pharmaceuticals, powdered food are only few examples of end products containing nano-sized particles (NPs), generally added to improve the product quality. To evaluate correctly benefits versus risks of engineered nanomaterials, it would be necessary to well characterize the NPs as manufactured, as delivered for use in products, as present in the product matrix, as used in toxicity testing, and as present in biological fluids and tissues, this because, the physicochemical parameters might change in various environments. On analytical point of view the identification, quantification and characterization of NPs in food matrices and in cosmetic or personal care products pose significant challenges, because NPs are usually present at low concentration levels and the matrices in which they are dispersed, are complexes and often incompatible with analytical instruments that would be required for their detection and characterization. This presentation recalls some analytical techniques suitable for the detection, characterization and quantification of NPs in food and cosmetics products, and reports their recent application in characterizing specific metal and metal-oxide NPs in these two important industrial and market sectors

Declared and undeclared nano- and micro-particles in everyday products

The cosmetic and the food sectors are deeply involved in the use of nanomaterials and/or nanoparticles. They are added intentionally to products during the production, preparation, treatment, packaging, transport and storage of stuffs to improve specific properties. Because of their several uses, in the light of an awake use of products by consumers, there is the need to study and to understand the NPs properties, and to analyze their impact on environment and on humans. Field Flow fractionation (FFF) techniques are very useful for the characterization of nano- ad micro entities. Centrifugal-FFF, often coupled on-line with specific element detectors, such as ICP-MS, or the flow-FFF are the most common methods used to sort and size NPs. Size, along with shape, morphology and many other physicochemical parameters are, in fact, the principal characteristics, which have to be determined to evaluate the health or/and environmental effects caused by the NPs. This talk will present some examples, chosen in the fields of the cosmetics and food applications, in which the FFF methods show their contribution to the nanoparticle characterization

Soft nanomaterials in the agrifood sector

Products based on nanotechnology or containing nanoparticles (NPs) are found in the entire food chain, from cultivation (agriculture), to the industrial processing and packaging of foods. Nanoscale materials can be naturally occurring, may be intentionally added or may be the result of unintentional contamination. Intentionally added NPs are frequently used to improve taste, flavour, colour, texture, and consistency of foodstuffs, to increase absorption and bioavailability of nutraceuticals and health supplements, to develop food antimicrobials. Engineered nanomaterials result very useful also in food processing, food packaging, and storage include monitoring of food quality, safety, and biosecurity (for example, nanosensors for traceability and monitoring the condition of food during transport and storage). By focusing the attention on the intentionally added NPs, their functionalities (e.g. release of food additives) depend on the physicochemical properties of NPs (size and size distribution, surface area, shape, solubility and dissolution, reactivity, coagulation or aggregation state, chemical composition, etc.) and on the biological matrices (compounds that are present in the matrix and thermodynamic conditions). In this presentation, some examples of NPs used in the food chain are given, by distinguishing them between soft and hard nano-entities. Since the agricultural and food samples are heterogeneous systems, which may contain a mixture of natural and engineering NPs of different composition, their detection and characterization are usually very difficult and complex. In particular, nano-emulsions, micelles, nano-liposomes, solid lipid nanoparticles or nanostructured lipid carriers, biopolymers can be well characterised during their formulation by using many of the conventional analytical techniques (imaging, separation and spectroscopic techniques), but the sample pre-treatment necessary to reduce, for example the food matrix complexity, might introduce important alterations which make their in situ analysis sometimes almost impossible