Spectroscopic Techniques and Instrumentation

The energy range [ultraviolet (UV) to near infrared (NIR)] over which lanthanide luminescence is observed as one traverses the lanthanide series is substantial and cannot be covered readily by a single experimental combination of excitation source and detector. 

Luminescence of Lanthanide Ions in Coordination Compounds and Nanomaterials, First Edition. Edited by Ana de Bettencourt-Dias. 

This point is illustrated by example in Fig. 2.2 showing typical luminescence spectral data from several Ln ions. 

In this chapter we consider the most general elements of luminescence spectroscopy practice and instrumentation with a focus, where appropriate, on experimental aspects of luminescence spectroscopy that are unique to or specific to lanthanide-ion systems. In particular, we emphasise recent advances in spectroscopic hardware and data-processing 

1 Challenges in Design and Interpretation of Lanthanide Luminescence Experiments 

---

Spectroscopic Techniques and Instrumentation 71 Table 2.1 Common standards used for emission efficiency measurements... 

The final section, on analytical chemistry, is a combination of structure-elucidation techniques and instrumental optimizations. Instrumental analysis can be broken into several steps method development, instrumental optimization, data collection, and data analysis. The trend today in analytical instrumentation is computerization. Data collection and analysis are the main reasons for this. The chapters in this section cover all aspects of the process except data collection. Organic structure elucidation is really an extension of data analysis. These packages use spectroscopic data to determine what structural fragments are present and then try to determine... 

As the first commercial NMR instruments became available, a significant part of the empirical knowledge related to the structure and reactivity of organic compounds was under close scrutiny. Model compounds that could be used to test certain concepts or effects were subject to spectroscopic techniques and a framework for interpreting spectra based on structural properties began to develop. 

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. 

The general aim of this chapter is to focus on the major instrumental techniques that are used to analyse colorants associated with the textile coloration industries. The principal techniques that have been covered are spectroscopic techniques and chromatographic techniques. The capability and value of the techniques are highlighted by reference to relevant applications. Prior to focusing on the techniques, consideration is given to the nature of colorants and also general issues, such as sampling, that are important in an overall analytical procedure. Section... 

Terahertz (THz) spectroscopy systems utilize far-infrared radiation to extract molecular spectral information in an otherwise inaccessible region of the electromagnetic spectrum where various rotational, vibrational, and translational modes of molecules are located, 0.1-10 THz (Fig. 1). As the wavenumber range is narrowed, THz-radiation can yield more specific information about a particular chemical component within the system. Unlike most spectroscopic techniques, THz instrument measures the wave temporal electric field, which can be Fourier transformed to yield THz pulse amplitude and phase. This added capability allows precise... 

The state of copper in the prepared catalysts was studied by ESR spectroscopic technique and by thermal analysis in flow hydrogen medium. Experimental measurements were performed with a spectrometer ART-6 in X frequency bands analysis (u = 9010 MHz) and a thermoanalitical instrument SETARAM. 

All major modern atomic absorption and emission techniques and instrumentation are covered. Appendices with FAAS and GFAAS conditions have been added, and a new appendix with up-to-date hmits of detection for all the atomic spectroscopic techniques is included. Chemical speciation using hyphenated chromatographic-atomic emission spectroscopy is described as is a novel microwave induced plasma emission instrument for particle characterization. 

The development of atomic spectroscopic techniques and their appHcation to fundamental studies fostered the concurrent development of atomic theory and quantum mechanics. In turn, the better understanding of atomic theory has led to the implementation of many beneficial techniques and instrumental features in atomic spectroscopy, particularly for the reduction or elimination of interferences and background. 

All major modem atomic absorption and emission techniques and instrumentation are covered, including new MP-AES and triple quadrupole ICP-MS instruments. The relatively new technique of laser-induced breakdown spectroscopy (LIBS) has been added to Chapter 7 and is now currently being used on Mars in the Curiosity rover, which landed on the Red Planet in August 2012. Appendices with EAAS and GEAAS conditions have been added, and the appendix with limits of detection for all the atomic spectroscopic techniques has been updated from the sixth edition. The chapter on X-ray has been significantly revised by Dr. Alexander Seyfarth, the new coauthor of the chapter, to reflect the state of the art in XRP, XRD, and related techniques. Many new graphics have been added. 

Because of the wide variety of spectroscopic techniques and the even wider variety of applications, spectroscopy has had a far-reaching and diverse impact on industry. The majority of its impact comes from the power of the techniques to help scientists and engineers improve processes and solve problems rather than from marketing spectroscopic instrumentation to the general public. 

Plastics identification by spectroscopic techniques has increasingly focused on the use of near-infrared and Raman spectroscopic techniques. LLA Instruments, in conjunction with Daimler-Chrysler [78] have developed a superfast near-infrared (NIR) sensor system that has been used to separate mixed plastics by type from shredded automotive parts. NIR spectroscopy uses the near infrared region of the electromagnetic spectrum (from about 800 to 2500 nm). Their two-phase process initially separates bright and colored polymers and black polypropylene from the mix. A second long-wavelength NIR sensor is employed to then separate black plastics such as PC, PMMA, ABS, PC/ABS blends, and others. 

The components of an ICP mass spectrometer are generally more complex than other atomic spectroscopic techniques, and as a result, more time is required to carry out routine maintenance to ensure that the instrument is performing to the best of its ability. Some tasks involve a simple visual inspection of a part, whereas others involve cleaning or changing components on a regular basis. However, routine maintenance is such a critical part of owning an ICP-MS system that it can impact both the performance and the lifetime of the instrument. 

Instrumental Methods. A variety of spectroscopic techniques are available for the characterization of siUcones. Descriptions of these techniques and Hterature references relevant to siUcone analysis are summarized in Table 12. 

---