Continuous tracing, molecular systems

Total molecular wave function, permutational symmetry, 661-668, 674-678 Tracing techniques, molecular systems, multidegenerate nonlinear coupling continuous tracing, component phase, 236-241... 

Common gas chromatographic detectors that are not element- or metal-specific, atomic absorption and atomic emission detectors that are element-specific, and mass spectrometric detectors have all been used with the hydride systems. Flame atomic absorption and emission spectrometers do not have sufficiently low detection limits to be useful for trace element work. Atomic fluorescence [37] and molecular flame emission [38-40] were used by a few investigators only. The most frequently employed detectors are based on microwave-induced plasma emission, helium glow discharges, and quartz tube atomizers with atomic absorption spectrometers. A review of such systems as applied to the determination of arsenic, associated with an extensive bibliography, is available in the literature [36]. In addition, a continuous hydride generation system was coupled to a direct-current plasma emission spectrometer for the determination of arsenite, arsenate, and total arsenic in water and tuna fish samples [41]. 

This section describes a new method for detection and identification of intermediate radical species in the gas phase. This method is based upon the establishment of an alkah ion attachment to radicals through termolecular reaction. It provides mass spectra of quasi-molecular ions formed by lithium ion attachment to the radical species (R) under high pressure. Results are obtained in the form of a mass spec-trometric trace of LT adduct radicals. The advantages of the present method are (i) a measme of mass is a guide to radical identity, (ii) adaptability to a condition of higher pressures, and (hi) direct continuous measurements of any species in dynamic systems can be made. The method is apphed to the study of the microwave (MW) discharge in CH, C, CHy02, or CH4/N2 and was successfully... 

The same epoxy system in the uncured state was studied by DSC/FT-IR as a function of activator/resin ratio. Excess activator (over stoichiometric amounts) generated a single peak exotherm on the DSC trace while the activator deficient system produced a double peak exotherm. The DSC cell was placed on an FT-IR microscope stage. While the epoxy system was being heated, infinred spectra were continually collected by micro-reflection/absorption. Spectra from the two systems were compared and interpreted to explain on a molecular level the noted differences in the DSC curves. The FT-IR data confirmed that these detected differences were due to changes in the rate of cure and reaction mechanism. 

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