Nondestructive and destructive

In Chapter 7, approaches for visualization of zones in chromatograms are discussed, including use of nondestructive and destructive dyeing reagents, fluorescence quenching on layers with a fluorescent indicator, and densitometry. In Chapter 8, additional detection methods, such as those used for biologically active and radioactive zones, as well as the recovery of separated, detected zones by scraping and elution techniques are covered. 

Quality control of BDD electrodes is essential and is performed both by nondestructive and destructive testing methods. Nondestructive methods are either routine methods performed on each electrode (Raman spectroscopy to evaluate sp3/sp2... 

Corrosion prevention—material selection, corrosion inhibition, cathodic protection, galvanic corrosion prevention, and extensive nondestructive and destructive inspection protocols. ... 

The objective of this task is to expose various structural ceramics to conditions found in smail diesei engines, Commercially available ceramics, as well as new candidate monolithic and whisker-toughened ceramics, will be fabricated Into small MOR bars, nondestructively examined, and exposed to a variety of operating conditions within small diesel engines. Subsequent to exposure, the bars will be nondestructively and destructively examined and the results compared to an unexposed data base. 

The experimental techniques described above of charge—discharge and impedance are nondestructive. Tear-down analysis or disassembly of spent cells and an examination of the various components using experimental techniques such as Raman microscopy, atomic force microscopy, NMR spectroscopy, transmission electron microscopy, XAS, and the like can be carried out on materials-spent battery electrodes to better understand the phenomena that lead to degradation during use. These techniques provide diagnostic techniques that identify materials properties and materials interactions that limit lifetime, performance, and thermal stabiity. The accelerated rate calorimeter finds use in identifying safety-related situations that lead to thermal runaway and destruction of the battery. 

The hydrodesulfurization process is actually a specific hydrogenation process and, as employed in petroleum refining, can be classified as nondestructive or destructive. 

During the last few years, more progress has been achieved by hyphenating LC-NMR to MS. The LC-NMR-MS or LC-NMR/MS (referred to as LC-MS-NMR in this chapter) has expanded the structure-solving capabilities by obtaining simultaneously MS and NMR data from the same chromatographic peak. There are some compromises that have to be taken into account because of the differences between MS and NMR, such as sensitivity, solvent compatibility, and destructive versus nondestructive technique, discussed below. LC-MS has been used for many years as a preferred analytical technique however, with the development of electrospray ionization techniques, LC-MS has been routinely used for the analysis of complex mixtures in the pharmaceutical industry. LC-MS-NMR is a combination of LC-MS with electrospray and LC-NMR presented below. 

Detection can be carried out either with an on-line detector coupled to the eluent flow or by the collection and subsequent analysis of discrete fractions. For collected fractions, a range of analytical methods can be used, both quantitative (e.g., radiotracer and metal analysis) and more qualitative (e.g., microscopic techniques). On-line detectors suitable for coupling to the FFF channels include both nondestructive flow through cell systems and destructive analysis systems. It is often desirable to use on-line detection if possible because the total analysis time is much less than for discrete fraction analysis. Regardless of detector type, the dead volumes and flows in the system between the FFF channel and detector or fraction collector must be accurately determined and corrected for. 

The most important textural characteristic of a pectin gel is gel strength, and there are a number of good reviews on methods and instruments used to determine this (Mitchell, 1976 Crandall and Wicker, 1986 Alexos et al., 1991). Both nondestructive approaches, which measure the elastic properties of the gel, and destructive approaches, which measure the inelastic properties or breaking strength of a gel, are used. 

Nondestructive vs. Destructive Tests. The pectin grade depends somewhat on the evaluation method (61). Gel strength Instrumentation may be nondestructive which measures the elastic properties of a gel, or destructive which measures the Inelastic or breaking strength of a gel. A major pectin producer unsuccessfully tried several Instruments and methods for more than 20 years to measure both elasticity and rupture strength with a single test ( ). 

Activation analysis is a highly sensitive nondestructive technique for qualitative and quantitative determination of atomic conqx>sition of a sample. It has been particularly useful for determination of elements in complex samples (minerals, environmental samples, biological and archeological objects, etc.), because it provides a simple alternative to much more difficult, tedious and destructive techniques. Its main limitation is the demand for a strong irradiation source. 

Because the amoimt of lipophilic material in the extract can affect the active surface of the stationary phase and degrade the resolving power of the GC columns, an effective cleanup procedure is essential. Cleanup of extracts can be performed in either a nondestructive or destructive way. 

The nondestructive instrumental (INAA) and destructive radiochemical (radiochemical neutron activation analysis — RNAA) procedures of this method are discussed later in this chapter. Specific problems, such as chain decays, cyclic activation, and interferences, as well as typical appKcations have recently been discussed by Alfassi (2001) and the references therein. 

The availability of UV/VlS spectrophotometers has revitalized the examination of evidence for characteristics associated with color. Fibers, inks, and paints in particular can be examined nondestructively and characterized by a spectrum as well as the analyst s judgment of their color. Prior to the availability of UV/VIS MSP, obtaining a visible spectrum of a fiber involved destructive extraction followed by colorimetry. Large numbers of fibers were needed, and potentially useful inter- and intrasample variations in color were lost. (Particular applications of MSP to color determinations are addressed in the application chapters that follow.)... 

Dry film gauging Electrical and magnetic nondestructive and visual destructive equipment for determining thickness are described in several places (Figs. 14.26 and 14.27). 

For each WPS a sample weld is performed to be subjected to a range of nondestructive examinations and destructive tests, the results of which are entered on a procedure qualification record (PQR), the whole operation being normally witnessed and certified by an independent third party. (If the tests meet specified requirements the WPS is qualified. )... 

---