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Ion Beam Analysis: Analytical Applications
Published in Vlado Valković, Low Energy Particle Accelerator-Based Technologies and Their Applications, 2022
Progress in accelerator-based nuclear analytical techniques (NAT) is associated with developments in areas ofBeam focusing and construction of microprobes.Sample preparation methods.Simultaneous use of several detection methods.Hardware and software for data collection and analysis.
Drowning
Published in Burkhard Madea, Asphyxiation, Suffocation,and Neck Pressure Deaths, 2020
Contradictory opinions exist on the diagnostic value of the diatom test for drowning. The main criticism stems from the discovery of diatoms in non-drowned corpses. In principle, due to the ubiquity of diatoms in water, air and soil, false-positives can result from AM penetration of diatoms (ingestion of diatom-laden beverages or food, inhalation of aerophilic diatoms, swallowing or aspiration of water by swimmers or divers) and PM penetration during submersion (through AM wounds and PM artefacts; at high hydrostatic pressures). Contamination may also occur during tissue sampling at autopsy and in the laboratory during procedures for sample preparation; these include instruments, gloves, paper, water supplies, reagents and glassware, which are all potential contamination sources.
Commercial Production of Radioisotopes for Nuclear Medicine
Published in Garimella V. S. Rayudu, Lelio G. Colombetti, Radiotracers for Medical Applications, 2019
In any radioisotope production, precautions must be taken to insure that impurities are not introduced into the sample prior to the irradiation of the sample. Contamination of a sample can occur in many ways, some of which are not so obvious and can quite often lead to production difficulties. Experience has shown that one can expect contamination from the shipping, storage, and weighing of the samples; from irradiation containers; from spatulas, drills, knives, and other tools used to prepare the sample; from acids, solvents, crucibles, and other equipment used in preirradiation sample preparation; and from fingerprints. In short, anything which comes into intimate contact with the sample can introduce contaminants into the sample. In general, the number of preirradiation sample preparation steps should be minimized.
X-ray spectrometry imaging and chemical speciation assisting to understand the toxic effects of copper oxide nanoparticles on zebrafish (Danio rerio)
Published in Nanotoxicology, 2022
Joyce Ribeiro Santos-Rasera, Rafael Giovanini de Lima, Dejane Santos Alves, Regina Teresa Rosim Monteiro, Hudson Wallace Pereira de Carvalho
Spectroscopic techniques, such as X-ray fluorescence spectroscopy (XRF) is able to identify, locate and quantify chemical elements, while X-ray absorption spectroscopy (XAS) can reveal their chemical environment, oxidation state, and symmetry. Although powerful, these techniques are not as spread in ecotoxicology as in materials science. Some of the challenges regard strategies for mapping whole organisms and detecting trace elements, this latter task has been mostly accomplished by acid digestion and the destruction of biological tissues, without actually taking a picture of the organisms (Wang 2022). Sample preparation is also challenging because it has to preserve the elements in the proper cell compartment, otherwise one may obtain misleading results. (Jin et al., 2017). The literature reports applications of isolated XRF (Mages et al. 2008) and XAS in aquatic organisms (Beauchemin et al. 2004; Misra et al. 2012; Saibu et al. 2018; Kuwabara et al. 2007). Fewer studies have combined both tools such as reported by Adams et al. (2016) and Santos-Rasera et al. (2019).
Unraveling the complexity of the extracellular vesicle landscape with advanced proteomics
Published in Expert Review of Proteomics, 2022
Julia Morales-Sanfrutos, Javier Munoz
In principle, the relatively low complexity as well as the low dynamic range of proteins in EVs makes them ideal for direct MS analysis.Figure 2 In reality, however, EVs preparations are prone to contamination with other EVs structures as well as many other non-vesicular components that notably increase their complexity. Additionally, the extreme high dynamic range of soluble proteins present in biological fluids contaminates preparations with highly abundant soluble proteins that difficult the identification of vesicular proteins of low abundance. Given the protein composition of EVs and the comparative nature of most studies, arguably, the most suited approach for profiling these samples is single-shot label-free proteomics. In the last years, the field of proteomics has matured enormously owing to developments in sample preparation, mass spectrometry, and computational approaches. These advances enable the analysis of EVs at unprecedented sensitivity and high-throughput. In this section, we review these developments and discuss their applicability for the analysis of EVs. Sample preparation
Ultra-preconcentration of common herbicides in aqueous samples using solid phase extraction combined with dispersive liquid–liquid microextraction followed by HPLC–UV
Published in Toxin Reviews, 2021
Toraj Ahmadi-Jouibari, Negar Noori, Kiomars Sharafi, Nazir Fattahi
Sample preparation is one critical step of an analytical procedure and an integral part of any analysis. Optimized sample preparation is necessary, not only to reduce the time taken but because each step adds a potential source of error. The amount of sample preparation needed depends on the sample matrix and the properties and level of analyte to be determined. The determination of trace contaminants in complex matrices, such as biological samples and highly saline solutions, often requires extensive sample extraction and preparation regimes prior to instrumental analysis (Ma et al. 2018, 2019). Several techniques have been developed for the extraction and preconcentration of contaminants from aqueous samples, such as solid-phase extraction (SPE) (Rivoira et al. 2015, Wang et al. 2019), solid-phase microextraction (SPME) (Mirzajani et al. 2017, Pei et al. 2019), liquid–liquid extraction (LLE) (Duca et al. 2014), continuous sample drop flow microextraction (CSDFME) (Karimaei et al. 2017), homogeneous liquid–liquid extraction (HLLE) (Ebrahimzadeh et al. 2007), and liquid-phase microextraction (LPME) (Yilmaz and Soylak 2016, Reclo et al. 2017).