Instrumentation concepts resolution

Basic spectroscopic measurements involve the instrumental concepts of bandpass and resolution, signal-to-noise ratio, dynamic range, stray light, wavelength accuracy and precision, and photometric accuracy and precision. These concepts were described in Chapter 1. 

It should be noted that these results are only preliminary and have to be considered as a proof of concept. As is clear from eq. (2) the phase contrast can be improved drastically by improving the global resolution and sensitivity of the instrument. Currently, a high resolution desktop system is under construction [5] in which the resolution is much better than that of the instrument used in this work, and in which the phase contrast is expected to be stronger by one order of magnitude. 

In principle GD-MS is very well suited for analysis of layers, also, and all concepts developed for SNMS (Sect. 3.3) can be used to calculate the concentration-depth profile from the measured intensity-time profile by use of relative or absolute sensitivity factors [3.199]. So far, however, acceptance of this technique is hesitant compared with GD-OES. The main factors limiting wider acceptance are the greater cost of the instrument and the fact that no commercial ion source has yet been optimized for this purpose. The literature therefore contains only preliminary results from analysis of layers obtained with either modified sources of the commercial instrument [3.200, 3.201] or with homebuilt sources coupled to quadrupole [3.199], sector field [3.202], or time-of-flight instruments [3.203]. To summarize, the future success of GD-MS in this field of application strongly depends on the availability of commercial sources with adequate depth resolution comparable with that of GD-OES. 

A second objective was to develop new instrumentation techniques and apply them to materials having known characteristics. Since interpretation of rapid phenomena prior to and accompanying deton require novel approaches and concepts for resolution, the exisitng techniques had to be either modified or replaced by other methods... 

The ten chapters are organized into three main sections. The first four chapters (Jansson) introduce the reader to basic concepts and progress through a survey of both traditional linear and modern nonlinear methods. Chapters 5 (Jansson), 6 (Blass and Halsey), and 7 (Halsey and Blass) detail specific applications of a proven method to the fields of electron spectroscopy for chemical analysis (ESCA) and high-resolution infrared spectroscopy via three different instrumental techniques. Also included are brief examples of applications to nuclear and Raman spectroscopy. The final section, Chapters 8 (Frieden), 9 (Howard), and 10 (Howard), illustrates recent work and reveals some directions for potential future research. 

Bertsch, W. (1999) Two-dimensional gas chromatography. Concepts, instrumentation, and applications-part 1 Fundamentals, conventional two-dimensional gas chromatography, selected applications. J. High Resolut. Chromatogr. 22 647-665. 

Preparative LC involves more than just a scale-up of instrumentation and column size (3). Sample loads must be far greater to achieve a sufficient amount of separated materials. Analytical LC developed the concepts of high resolution and high speeds. Today, specialized instruments, columns, and column packing materials attempt to imitate these characteristics for scale-up of analytical separations to preparative separations on the laboratory and pilot-plant scale, j, i < V, ... 

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