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Current Understanding of Interactions between Nanoparticles and the Immune System
Published in Raj Bawa, János Szebeni, Thomas J. Webster, Gerald F. Audette, Immune Aspects of Biopharmaceuticals and Nanomedicines, 2019
Marina A. Dobrovolskaia, Michael Shurin, Anna A. Shvedova
Reference standards are well-characterized materials with known properties. These materials can be used to validate toxicology protocols and ensure the quality of measurements specific to a given protocol measuring given end points. It is generally acknowledged that the lack of nanoparticle reference standards limits the validation of instruments, protocols, and materials used to assess exposure to nanomaterials and understand their biocompatibility. While many types of nanomaterials have been linked to certain types of immunotoxicity (e.g., cationic dendrimers are thrombogenic; PEGylated liposomes induce anaphylaxis), there are no standard reference materials to use for these and other types of immunotoxicity studies. Stefaniak et al. conducted a literature review and identified 25 nanomaterials that were considered to be candidate nanoparticle reference materials by standards development organizations worldwide (Stefaniak et al., 2013). Interestingly, this study found a limited consensus regarding the types of candidate nanoparticles between various organizations involved in the development of reference materials: the U.S. National Metrology Institute, the U.S. National Institute of Standards and Technology, the REFNANO project funded by the UK government, the Organization for Economic Cooperation and Development, and several NanoImpactNet projects (NanoImpactNet, NanoSustain, and NanoValid) funded by the European Commission (Stefaniak et al., 2013).
Air Sampling
Published in Martin B., S.Z., of Industrial Hygiene, 2018
Evaluating the impact of air contaminants necessitates the accurate determination of the amount of the contaminant present in a unit volume of air. This value defines the concentrations of the contaminant and is determined either directly from the airstream or following collection on a suitable medium. Calibrations are performed to establish the relationship between the instrument’s response and the airborne chemical contaminant concentration being measured. The reference standards used must be accurate and precise to produce well-characterized and reproducible calibrations.
Quality Control and Quality Assurance
Published in José L. Tadeo, Analysis of Pesticides in Food and Environmental Samples, 2019
Árpád Ambrus, Gabriella Suszter
The purity of reference standards and accuracy of their concentration in stock and working solutions are the basis of obtaining unbiased results. Pure reference standards should be stored excluding light and moisture at low temperatures preferably in a freezer. Under such strictly controlled conditions, the pure reference materials may be stored without degradation for up to ten years, substantially exceeding the expiry date specified by the suppliers [4].
Distribution and accumulation of heavy metals in Lake Manzala, Egypt
Published in Egyptian Journal of Basic and Applied Sciences, 2021
The study was carried out on Lake Manzala through summer, 2019, to monitor and evaluate the levels of some heavy metals and major oxides in water and sediments. Ten samples of both water and superficial bottom sediments have been collected. The sample sites have been chosen to cover sources of pollution near to discharges of most drains which consider the main source of pollution of the study area. Every one of the safeguards happened to limit dangers of the test tainting were followed during the assortment and treatment of tests. These samples have been chemically analyzed for the determination of their major oxides (Silica oxide SiO2, Aluminum oxide Al2O3, Ferric oxide Fe2O3, Magnesium oxide MgO, Calcium oxide CaO, Sodium oxide Na2O and Potassium oxide K2O) and a few heavy metals (Cu, Zn, and Pb, Fe, Mn and Cd). The study used the standard of the American Public Health Association (APHA) [11] for the collection, preservation and digestion technique. Heavy metals concentrations were measured using a graphite furnace atomic absorption spectrometer (Buck Scientific Company, USA) after the digestion technique. Calibration standards and quality control samples have been prepared freshly daily. The reference standard materials used to assess the precision and accuracy of the procedure. The study used analytical grade chemicals of certified standard solutions for the aim of sample preparation and its analysis.