1.1 Introduction
The concentration of metal species in analytical laboratories has frequently been measured by observing an atom’s interaction with electromagnetic radiation (e.g. light.) Since atomic species produce a unique line spectrum, the observation of these transitions can be used to both identify a particular metal (spectroscopy) and its concentration (spectrometry). While these terms are sometimes used interchangeably in common speech, spectroscopy is the study of the interaction of radiation with matter and the term spectrometry is applied to the measurement of concentrations of a compound (analyte). Before spectroscopic techniques or instruments are presented in the following chapters, it is important to review a general understanding of the ways electromagnetic radiation interacts with sample molecules.
An atom’s interaction with electromagnetic radiation is critical in detecting its presence and concentration. It is necessary to manipulate the signal radiation to measure small concentrations of analyte. This is performed by placing optical components, for example a mirror or prism, in the path of the radiation to alter the property or path of the radiation. These devices will be discussed in the second half of this chapter, given their importance to various types of atomic absorbance spectroscopy (AAS) and inductively coupled plasma – atomic emission spectroscopy (ICP-AES). Once a general understanding of their function has been illustrated, the following chapters will illustrate how these components are utilized in series to achieve different purposes.
Before this discussion is initiated, it is necessary to become familiar with abbreviations that are commonly used in analytical laboratories. Given the length of many instrument’s names, it has become common practice to abbreviate them. Liquid chromatography (LC) and nuclear magnetic resonance (NMR) are likely two of these acronyms that students should be familiar with from organic chemistry. The following table contains the common acronyms of instruments and techniques that are used to measure metal concentrations.
Table 1.1 Common Types of Spectrometric Analyses and Their Acronyms
| Acronym | Technique/Instrument |
| AAS | Atomic Absorption Spectrometry |
| AES | Atomic Emission Spectrometry |
| OES | Optical Emission Spectrometry |
| FAAS | Flame Atomic Absorption Spectrometry |
| FAES | Flame Atomic Emission Spectrometry |
| ICP | Inductively Coupled Plasma |
| ICP-AES or OES | Inductively Coupled Plasma-Atomic Emission Spectrometry (Optical Emission Spectroscopy) |
| ICP-MS | Inductively Coupled Plasma-Mass Spectrometry |
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