ATOMIC ABSORPTION SPECTROSCOPY Edited by Muhammad Akhyar Farrukh Atomic Absorption Spectroscopy Edited by Muhammad Akhyar Farrukh Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2011 InTech All chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. 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DepositPhotos First published January, 2012 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from [email protected] Atomic Absorption Spectroscopy, Edited by Muhammad Akhyar Farrukh p. cm. ISBN 978-953-307-817-5 free online editions of InTech Books and Journals can be found at www.intechopen.com Contents Preface IX Chapter 1 Atomic Absorption Spectrometry (AAS) 1 R. García and A. P. Báez Chapter 2 State-of-the-Art and Trends in Atomic Absorption Spectrometry 13 Hélcio José Izário Filho, Rodrigo Fernando dos Santos Salazar, Maria da Rosa Capri, Ângelo Capri Neto, Marco Aurélio Kondracki de Alcântara and André Luís de Castro Peixoto Chapter 3 Elemental Profiling: Its Role and Regulations 37 Ajai Prakash Gupta and Suphla Gupta Chapter 4 Microextraction Techniques as a Sample Preparation Step for Metal Analysis 61 Pourya Biparva and Amir Abbas Matin Chapter 5 Application of Atomic Absorption for Determination of Metal Nanoparticles in Organic-Inorganic Nanocomposites 89 Roozbeh Javad Kalbasi and Neda Mosaddegh Chapter 6 Flame Spectrometry in Analysis of Refractory Oxide Single Crystals 105 T.V. Sheina and K.N. Belikov Chapter 7 Interference Effects of Excess Ca, Ba and Sr on Mg Absorbance During Flame Atomic Absorption Spectrometry: Characterization in Terms of a Simplified Collisional Rate Model 131 Mark F. Zaranyika, Albert T. Chirenje and Courtie Mahamadi Chapter 8 Nutritional Metals in Foods by AAS 143 Mary Millikan VI Contents Chapter 9 Comparative Assessment of the Mineral Content of a Latin American Raw Sausage Made by Traditional or Non-Traditional Processes 167 Roberto González-Tenorio, Ana Fernández-Diez, Irma Caro and Javier Mateo Chapter 10 Analysis of High Solid Content in Biological Samples by Flame Atomic Absorption Spectrometry 183 Lué-Merú Marcó Parra Chapter 11 Mineral Content and Physicochemical Properties in Female Rats Bone During Growing Stage 201 Margarita Hernández-Urbiola, Astrid L. Giraldo-Betancur, Daniel Jimenez-Mendoza, Esther Pérez-Torrero, Isela Rojas–Molina, María de los Angeles Aguilera-Barreiro, Carolina Muñoz-Torres and Mario E. Rodríguez-García Chapter 12 Activation of Bentonite and Talc by Acetic Acid as a Carbonation Feedstock for Mineral Storage of CO2 221 Petr Ptáček, Magdaléna Nosková, František Šoukal, Tomáš Opravil, Jaromír Havlica and Jiří Brandštetr Preface Spectroscopy is the study of absorption and emission of electromagnetic radiation due to the interaction between matter and energy, which depends on the wavelength of the respective radiation. Analytical Chemistry is the branch of chemistry that deals with the study of qualitative, as well as quantitative analysis, of samples. Different spectroscopic techniques like UV-Visible, Atomic Absorption, Flame Emission, Molecular Fluorescence, Phosphorescence, Chemiluminescence, Infrared, Nuclear Magnetic Resonance, Raman, X-Ray, Mass, Electron, Mössbauer are being used for this purpose. Atomic Absorption Spectroscopy (AAS) is one of the spectroscopic and analytical techniques, used for the qualitative and quantitative determination of elements employing the absorption of electromagnetic energy of a particular wavelength, usually ultraviolet or visible region, by free atoms in the gaseous state. The technique is being used for the determination of metals in different samples like food, drugs, nanomaterials, biomaterials, environmental, forensics and industrial wastes. There is a dire need to provide scholars all over the world with the recent advancements going on in research using analytical techniques. This book is an effort of the authors in the field of AAS, covering topics from basic to advanced levels. The chapters in this book have been organized to keep the sequence in reading. In the first two chapters, introduction, history and basic principle of AAS have been described with detail instrumentation of all parts and sample preparation. Chapter 3 deals with elemental profiling, functions, dietary source, biochemistry and potential toxicity of metals along with comparative techniques used for the analysis. As sample preparation techniques are the most beneficial for proper analysis, chapter 4 discusses the microextraction techniques which are characteristics for an ideal sample preparation. Keeping in view the importance of nanomaterials and refractory materials, chapter 5 and 6 highlight the ways to characterize these materials by using AAS. The interference effects between elements can be characterized using a simplified rate model and through thermodynamic equilibrium approach as explained in chapter 7. The importance of metals in food and biological samples and their characterization with AAS have been given in chapters 8-11. Carbon capture and X Preface mineral storage, leaching experiments and estimation of metal contents by comparative techniques have been explained in chapter 12. The book will provide a good resource for teaching and research purposes. Muhammad Akhyar Farrukh Department of Chemistry G.C. University Lahore Pakistan 1 Atomic Absorption Spectrometry (AAS) R. García and A. P. Báez Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City Mexico 1. Introduction Atomic Absorption Spectrometry (AAS) is a technique for measuring quantities of chemical elements present in environmental samples by measuring the absorbed radiation by the chemical element of interest. This is done by reading the spectra produced when the sample is excited by radiation. The atoms absorb ultraviolet or visible light and make transitions to higher energy levels. Atomic absorption methods measure the amount of energy in the form of photons of light that are absorbed by the sample. A detector measures the wavelengths of light transmitted by the sample, and compares them to the wavelengths which originally passed through the sample. A signal processor then integrates the changes in wavelength absorbed, which appear in the readout as peaks of energy absorption at discrete wavelengths. The energy required for an electron to leave an atom is known as ionization energy and is specific to each chemical element. When an electron moves from one energy level to another within the atom, a photon is emitted with energy E. Atoms of an element emit a characteristic spectral line. Every atom has its own distinct pattern of wavelengths at which it will absorb energy, due to the unique configuration of electrons in its outer shell. This enables the qualitative analysis of a sample. The concentration is calculated based on the Beer-Lambert law. Absorbance is directly proportional to the concentration of the analyte absorbed for the existing set of conditions. The concentration is usually determined from a calibration curve, obtained using standards of known concentration. However, applying the Beer-Lambert law directly in AAS is difficult due to: variations in atomization efficiency from the sample matrix, non-uniformity of concentration and path length of analyte atoms (in graphite furnace AA). The chemical methods used are based on matter interactions, i.e. chemical reactions. For a long period of time these methods were essentially empirical, involving, in most cases, great experimental skills. In analytical chemistry, AAS is a technique used mostly for determining the concentration of a particular metal element within a sample. AAS can be used to analyze the concentration of over 62 different metals in a solution. Although AAS dates to the nineteenth century, the modern form of this technique was largely developed during the 1950s by Alan Walsh and a team of Australian chemists working at the CSIRO (Commonwealth Science and Industry Research Organization) Division of Chemical Physics in Melbourne, Australia. Typically, the technique makes use of a flame to atomize