Basic Description of the Instrumentation

Soft ionization methods were developed over the last two decades, and allow the formation of gaseous molecular ions from large polymeric biomolecules. These methods allowed MS to be introduced to the biological chemistry area, and are now particularly useful for the study of proteins, glycoproteins, nucleic acids, and their reactions. 

Molecular weights are now readily determined for these molecules with very high precision and accuracy. Variation between the experimental and the predicted MW of a protein (predicted from its DNA code) help in the determination of post-translational modifications of the polypeptide chain. Noncovalent interactions between biomolecules and ligands may also be studied using soft ionization methods. 

Mass sepetrometry has also been used to analyze nucleic acid mutations and polymorphisms, and for the identification and chemical characterization of microbial cells. 

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We present the basic concepts and methods for the measurement of infrared and Raman vibrational optical activity (VOA). These two forms of VOA are referred to as infrared vibrational circular dichroism (VCD) and Raman optical activity (ROA), respectively The principal aim of the article is to provide detailed descriptions of the instrumentation and measurement methods associated with VCD and ROA in general, and Fourier transform VCD and multichannel CCD ROA, in particular. Although VCD and ROA are closely related spectroscopic techniques, the instrumentation and measurement techniques differ markedly. These two forms of VOA will be compared and the reasons behinds their differences, now and in the future, will be explored. 

In this chapter, we will provide a basic description of the various types of fixed-income instruments encountered in the European markets as well as the definitions of some key terms and concepts that will assist the reader throughout the remainder of the book. Important groups of investors in these markets are briefly discussed in the last section of the chapter. 

This section provides a brief discussion of the basic theoretical concepts of CE (including separation mechanisms), a description of CE instrumentation, and some guidelines in selecting conditions for a CE separation. Readers interested in more detailed presentations of CE theory and practice may consult References 1 to 8. Several general reviews of CE have been published,911 as well as specific reviews of protein analysis by CE.12-16... 

A detailed description of IC is given in reference 1 however, the basic principles of the method can best be described by an example. Figure 1 schematically represents both an anion and a cation IC analysis. In both cases, the instrumentation involves a pumping system, an eluent, an injection valve, an ion-exchange separator column, an ion-exchange suppressor column and a conductivity cell. The sample is first injected into the flow system then the well known reaction equilibrium shown in Figure 1 results in the separation of sample anions or cations on the separator column (2). 

In this section, a brief, qualitative description of the physics behind NQR, with sufficient details to understand its working in the context of explosives detection, is provided. The reader interested in a more detailed discussion is referred to these review articles and the references therein [1-4], Basic NQR instrumentation and how the physics and hardware relate to sensitivity are also discussed. 

The VI is used to count scattered photons using a National Instruments M622x PC board, and the basic functions of parts to C are described in the text. The detailed meaning of each icon, along with descriptions of the controlhng inputs and outputs, can be seen in LabVIEW by positioning the mouse cursor on the icon. See also the discussion in Chapter III of the use of LabVIEW in interfacing situations. 

This section is addressed to the person who has not seen or used radiation instruments. Its purpose is to present a general description of the physical appearance and operation of the basic components of a radiation counting system. Every component is treated like a black box, i.e., input and output are discussed without any details about how the output is obtained. Details about the construction and operation of individual units are given in later chapters. 

Instrumentation. From the description of the fundamentals of magnetic resonance spectroscopy, basic building blocks and functional elements of the experiment can... 

This article first briefly surveys the history of Raman spectroscopy applied to electrochemistry, followed by a brief outline of the basic principles of surface Raman spectroscopy. The SERS phenomena and mechanisms are then introduced. This is followed by a detailed description of Raman instrumentation, and the... 

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