Mass spectrometry has developed into a platform for the assessment of health, sensory, quality and safety aspects of food. Current nutrition research focuses on unravelling the link between acute or chronic dietary and nutrient intake and the physiological effects at cellular, tissue and whole body level. The bioavailability and bioefficacy of food constituents and dose-effect correlations are key to understanding the impact of food on defined health outcomes. To generate this information, appropriate analytical tools are required to identify and quantify minute amounts of individual compounds in highly complex matrices (such as food or biological fluids) and to monitor molecular changes in the body in a highly specific and sensitive manner. Mass spectrometry has become the method of choice for such work and now has broad applications throughout all areas of nutrition research. This book focuses the contribution of mass spectrometry to the advancement of nutrition research. Aimed at students, teachers and researchers, it provides a link between nutrition and analytical biochemistry. It guides nutritionists to the appropriate techniques for their work and introduces analytical biochemists to new fields of application in nutrition and health. The first part of the book is dedicated to the assessment of macro- and micro-nutrient status with a view to making dietary recommendations for the treatment of diet-related diseases. The second part shows how mass spectrometry has changed nutrition research in fields like energy metabolism, body composition, protein turnover, immune modulation and cardiovascular health.

Volume 5: Elemental and Isotope Ratio Mass Spectrometry

This volume focuses on (1) the plethora of mostly atomic ionization techniques that have been coupled to MS for elemental analysis, the measurement of isotope ratios, and even the determination of inorganic compounds and (2) the precise measurement of isotope ratios of organic elements as small gas molecules by isotope ratio mass spectrometry (IRMS). Chapter 1 contains a description of inductively coupled plasma (ICP) MS, its requirements for sample preparation and introduction. The chapter also covers argon ICP, ion extraction, various mass analyzers, and the numerous application areas including environmental, geochemical, biomedical, nuclear, semiconductor, and speciation. Other atomic sources include the microwave plasma, which can be used as either an atomic ionization source or as a soft molecular ionization source, flames, spark sources, and glow discharges, including the types of mass spectrometers and separation approaches to which interfaces can be made.

Chapter 2 discusses the application of electrospray ionization (EI) MS, also described in Volume 6, to inorganic analysis. Secondary ion and neutral MS (Chapter 3) can be used to determine trace elements in solids, particularly on their surface, with high spatial resolution. Atmospheric aerosols can also be studied using laser(s) for desorption and ionization of analytes in solids (Chapter 4). Thermal ionization MS, where sample atoms or molecules are ionized as they evaporate from the surface of a hot filament, is the focus of Chapter 5. Special applications are in Chapter 6, which covers accelerator MS, and Chapter 7, where large calutrons can be contrasted to the small analyzers that are taken aboard spacecraft, for example.

Chapter 8 focuses on IRMS for precise isotope ratio measurements. The highest level of precision can only be accomplished through use of a mass spectrometer specifically esigned for the purpose of making differential measurements. A key advance is direct conversion of organic compounds into small gas molecules for measurement, leading to important uses ranging from geology to biomedical sciences.

* reviews the wide range of ionization and isotope methods used in inorganic mass spectrometry today * features tutorials describing the key principles and instrumentation relevant to each method * evaluates practical applications for the analysis of environmental, biological, biomedical, nutritional, geological, nuclear, microelectronic and extra-terrestrial materials * includes more than 3400 references, 100 tables and 500 figures of which more than 200 are in color