Dr in Chemistry, 1995. Since 1999 he is an Associated Professor at the Department of Analytical Chemistry, University of A Coruña. Fields of expertise: Quality Control and Chemometrics. In Chemometrics, main interests are in multivariate regression and pattern recognition methods (either, unsupervised and supervised). In the Atomic Spectrometry arena, he applied formal optimisation techniques to optimize analytical protocols (experimental design and Nelder and Mead simplex) and applied multivariate regression tools to cope with spectral and chemical interferences in ETAAS (traditional sample introduction and slurry-based).

Basic Chemometric Techniques in Atomic Spectroscopy 2nd Edition

By José M. Andrade-Garda

The Royal Society of Chemistry

Copyright © 2013 The Royal Society of Chemistry
All rights reserved.
ISBN: 978-1-84973-796-8

Contents

List of Contributors,
Chapter 1 An Overview of Atomic Spectrometric Techniques Alfredo Sanz-Medel, Rosario Pereiro and José Manuel Costa-Fernández,
Chapter 2 Classical Linear Regression by the Least Squares Method José Manuel Andrade-Garda, Alatzne Carlosena-Zubieta, Rosa María Soto-Ferreiro, Javier Teran-Baamonde and Michael Thompson,
Chapter 3 Implementing a Robust Methodology: Experimental Designs and Optimisation Xavier Tomàs-Morer, Lucinio González-Sabaté, Laura Fernández-Ruano and María Paz Gómez-Carracedo,
Chapter 4 Ordinary Multiple Linear Regression and Principal Components Regression Joan Ferré-Baldrich and Ricard Boqué-Martí,
Chapter 5 Partial Least-Squares Regression José Manuel Andrade-Garda, Alatzne Carlosena-Zubieta, Ricard Boqué-Martí and Joan Ferré-Baldrich,
Chapter 6 Multivariate Regression using Artificial Neural Networks and Support Vector Machines José Manuel Andrade-Garda, Marcos Gestal-Pose, Francisco Abel Cedrón-Santaeufemia, Julián Dorado-de-la-Calle and María Paz Gómez-Carracedo,
Subject Index,

CHAPTER 1

An Overview of Atomic Spectrometric Techniques

ALFREDO SANZ-MEDEL, ROSARIO PEREIRO AND JOSÉ MANUEL COSTA-FERNÁNDEZ

Department of Physical and Analytical Chemistry, University of Oviedo, Oviedo, Spain

1.1 Introduction: Basis of Analytical Atomic Spectrometric Techniques

Analytical atomic spectrometry comprises a great number of techniques based on distinct principles, with different performance characteristics and hence with varied application scopes, but in all cases providing elemental chemical information about the composition of samples. As shown in Figure 1.1, these techniques can be classified into three main groups according to the type of particle detected: optical spectrometry, where the intensity of either nonabsorbed photons (absorption) or emitted photons (emission and fluorescence) is detected as a function of photon energy (in most cases, plotted against wavelength); mass spectrometry (MS), where the number of atomic ions is determined as a function of their mass-to-charge ratio; and electron spectroscopy, where the number of electrons ejected from a given sample is measured according to their kinetic energy, which is directly related to the bonding energy of the corresponding electron in a given atom.

X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) are the two main techniques based on electron spectroscopy. In XPS, a source of photons in the X-ray energy range is used to irradiate the sample. Superficial atoms emit electrons (called photoelectrons) after the direct transfer of energy from the photon to a core-level electron (see Figure 1.2a). Photoelectrons are subsequently separated according to their kinetic energy, and counted. The kinetic energy of the emitted photoelectrons will depend on the energy of the original X-ray photons (the irradiating photon source should be monochromatic) and also on the atomic and, in some cases, the molecular environment from which they come. This, in turn, allows knowledge of the sample elemental composition and also provides important information about oxidation states and chemical bonds because the stronger the binding to the atom, the lower the photoelectr