Download or read book The Development of Analytical Methods for the Determination of Selenium written by Kieran James McLaughlin and published by . This book was released on 1991 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selenium Contamination in Water written by Pooja Devi and published by John Wiley & Sons. This book was released on 2021-05-12 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: The contamination of environment and water resources by Selenium (Se) and its oxyanions from various sources are emerging contaminants of significant health and environmental concern. The primary sources include agricultural drainage water, mine drainage, residues from fossil fuels, thermoelectric power plants, oil refineries, and metal ores. Various methods and technologies have been developed which focus on the treatment of selenium-containing waters and wastewater. High concentrations of selenium in water cause various adverse impact to human health, such as carcinogenic, genotoxic, and cytotoxic effects. But in the lower concentrations, it is a useful constituent of the biological system. The range between toxicity and deficiency of selenium is minimal (40 to 400 μg per day), due to its dual nature. Selenium Contamination in Water contains the latest status and information on selenium’s origin, its chemistry and its toxicity to humans. The book represents a comprehensive and advanced reference book for students, researchers, practitioners, and policymakers in working in the field of metalloids, in particular selenium. A special emphasis is given on its geological distribution, monitoring techniques, and remedial technologies. As such, the authors critically analyze the various techniques used for the monitoring and removal of selenium from water. Featuring chapters arranged according to the major themes of the latest research, with specific case-studies from industrial experiences of selenium detection and removal, Selenium Contamination in Water will be particularly valued by researchers, practitioners, and policymakers in working in the field of metalloids including selenium.
Download or read book Analytical Method Development for Selenium containing Proteins of Clinical Interest written by Mariana Arce-Osuna and published by . This book was released on 2005 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development and Validation of Extraction and Analytical Methods for Speciation Analysis of Selenised Yeast Using Hyphenated Mass Spectrometric Techniques written by Patrick Thomas Ward and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selenium is an essential trace element for human and animal health. Numerous studies reported selenium to possess antioxidant effects, anticarcinogenicity and fertility improvements to name a few. The assimilation of selenium into the yeast via the sulfur metabolic pathway creates selenised yeast which is one of the primary sources of selenium supplementation. In this thesis, novel approaches to the extraction and characterisation of commercial selenised yeast products are described. Extraction procedures were developed for selenomethionine determination. These methods involved both enzymatic and chemical extraction approaches and utilised microwave and ultrasonication energy for the purpose of liberating intracellular selenomethionine. Both the enzymatic and chemical extraction methods were subsequently validated for determination of the analyte. A quantitative assay was also developed for the determination of chiral enantiomers of selenomethionine. The method was applied to commercially-available selenised yeast to characterise any differences in the water-soluble extracts of the products. Significant differences were evident, not only from chiral composition but also from the selenocompounds present in the water extract. Further screening of the water extract by HPLC-ICP-MS revealed numerous other selenocompounds. While coupling of HPLC to ICP-MS was sufficient as an investigative screening tool, selenocompound identification was not possible unless a standard of the analyte was available. To combat these issues other mass spectrometric techniques were investigated. The target water-soluble extracts were lyophilised and resuspended to increase analyte concentration and were analysed by liquid chromatography electrospray quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS). Selenium-containing species were confirmed by selenium's unique isotopic pattern. Determination of the elemental composition and proposed structure of some of these previously unreported selenocompounds was possible due to the accurate molecular mass from the first mass analyser and from MS2 fragmentation analysis. Therefore, LC- ESI-QTOF-MS may be used as a fingerprint tool to make comparisons between commercially-available selenised yeast products.
Download or read book Environmental Chemistry of Selenium written by William T. Frankenberger and published by CRC Press. This book was released on 1998-02-03 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Written as a complement to the definitive work selenium in the Environment (Marcel Dekker, Inc.). Presents basic and the most recent applied research developments in selenium remediation-emphasizing field investigations as well as covering topics from analytical methods and modeling to regulatory aspects from federal and state perspectives. "
Download or read book Selenium Isotope Studies in Plants Development and Validation of a Novel Geochemical Tool and its Application to Organic Samples written by Banning, Helena and published by KIT Scientific Publishing. This book was released on 2017-02-13 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selenium (Se), being an essential nutrient and a toxin, enters the food chain mainly via plants. Selenium isotope signatures were proved to be an excellent redox tracer, making it a promising tool for the exploration of the Se cycle in plants. The analytical method is sensitive on organic samples and requires particular preparation methods, which were developed and validated in this study. Plant cultivation setups revealed the applicability of these methods to trace plant internal processes.
Download or read book Element Analysis of Biological Samples written by G. Venkatesh Iyengar and published by CRC Press. This book was released on 2020-11-25 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite the development of innovative new analytical techniques for biological trace element research, today's trace element investigators face formidable obstacles to obtaining reliable data. This complete reference identifies and assesses the challenges the analyst encounters at each stage of an analysis, and discusses the effects of various techniques on the sample. Three internationally recognized scientists and authors consider the effects of the numerous collection, storage, and sample preparatory techniques used in sample analysis. Proper analytical quality control, including such critical factors as sampling and sample preparation, specimen preservation and storage, and ashing, is examined. The book also looks at sample preparation methods unique to various instruments and speciation chemistry issues, and examines the link between chemical analysis and specimen banking. A previously unrecognized source of error, presampling factors, is also discussed.
Download or read book Analytical Methods in the Determination of Bioactive Compounds and Elements in Food written by Magdalena Jeszka-Skowron and published by Springer Nature. This book was released on 2021-02-02 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most bioactive compounds have antioxidant activity, particularly tocochromanols, phenolics (flavonoids and phenolic acids), methylxantines and capsaicinoids. Some of these compounds have also other properties important for human health. For example, vitamin E protects against oxidative stress, but it is also known for its “non-antioxidant” functions, including cell signalling and antiproliferation. Selenium compounds and indoleamins are the components of the antioxidant enzymes. Selenium makes vitamin E acquisition easier and controls its physiological functions. In taking part in enzymatic reactions and protecting the cell against free radicals, selenium shows immunomodulative, antiphlogistic, and antiviral activity. Capsaicinoids possess not only antioxidant, but also antibacterial, analgesic, weight-reducing and thermoregulation properties. Studies have also demonstrated their gastroprotective and anticancer properties. Analytical Methods in the Determination of Bioactive Compounds and Elements in Food explores both the influence of particular compounds on human health and the methods used for their determination. Chapters describe various aspects of food and plant analysis, including chromatographic and non‐chromatographic approaches as well as hyphenated techniques. Readers of this book will gain a comprehensive understanding of the important groups of bioactive compounds relevant to human health.
Download or read book High Resolution Continuum Source AAS written by Bernhard Welz and published by John Wiley & Sons. This book was released on 2006-03-06 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-resolution continuum source atomic absorption spectrometry (HR-CS AAS) is the most revolutionary innovation since the introduction of AAS in 1955. Here, the authors provide the first complete and comprehensive discussion of HR-CS AAS and its application to the analysis of a variety of difficult matrices. Published just in time with the first commercial instrument available for this new technique, the book is a must for all those who want to know more about HR-CS AAS, and in particular for all future users. The advantages of the new technique over conventional line-source AAS are clearly demonstrated using practical examples and numerous figures, many in full color. HR-CS AAS is overcoming essentially all the remaining limitations of established AAS, particularly the notorious problem of accurate background measurement and correction. Using a continuum radiation source and a CCD array detector makes the spectral environment visible to several tenths of a nanometer on both sides of the analytical line, tremendously facilitating method development and elimination of interferences. Conceived as a supplement to the standard reference work on AAS by B. Welz and M. Sperling, this book does not repeat such fundamentals as the principles of atomizers or atomization mechanisms. Instead, it is strictly focused on new and additional information required to profit from HR-CS AAS. It presents characteristic concentration for flame atomization and characteristic mass data for electrothermal atomization for all elements, as well as listing numerous secondary lines of lower sensitivity for the determination of higher analyte concentrations. The highly resolved molecular absorption spectra of nitric, sulfuric and phosphoric acids, observed in an air-acetylene flame, which are depicted together with the atomic lines of all elements, make it possible to predict potential spectral interferences.
Download or read book NBSIR written by and published by . This book was released on 1980 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1974-07 with total page 978 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Report written by United States. Food and Drug Administration and published by . This book was released on with total page 662 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Report of the Chief of the Food and Drug Administration written by United States. Food and Drug Administration and published by . This book was released on with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Information Circular written by and published by . This book was released on 1967 with total page 982 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selenium and Tellurium a Materials Survey written by Arnold Marshall Lansche and published by . This book was released on 1967 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analytical Chemistry of Selenium and Tellurium written by Irina Ivanovna Nazarenko and published by Coronet Books. This book was released on 1972 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comparison of instrumental methods for the determination of total selenium in environmental samples written by P M (Phil) Haygarth and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Choosing the appropriate instrumental method for the determination of total Se in environmental samples is difficult, considering the wide choice of methods currently available. By use of a sediment matrix, an objective comparison is made between fluorimetry, hydride generation atomic absorption spectrometry (HGAAS), hydride generation inductively coupled plasma atomic emission spectrometry (HG-ICP-AES), hydride generation inductively coupled plasma mass spectrometry (HG-ICP-MS) and radiochemical neutron activation analysis (RNAA) methods, involving technical criteria such as detection limits, reproducibility, time taken for analysis and interferences. A novel flow injection (FI) system was constructed and adapted for AAS to improve the efficiency of HG systems and shows that the method of hydride sample injection can have a substantial influence on over-all performance. Consideration is given to the definition and use of the term limit of detection. The conclusions of the study are that fluorimetry, HGAAS and HG-ICP-AES will continue to be usefully employed for routine, laboratory analyses, although with the fluorimetric method, performance characteristics are inferior in comparison with those of more recent analytical techniques. The FI-HGAAS method is superior to the single sample HGAAS system. For samples of low Se concentration, HG-ICP-MS and RNAA methods are superior.
