Abstract not available

Part I: Indirect determination of trace Organic Functional Groups Via Atomic Absorption Spectroscopy. Three indirect analysis techniques for the determination of isothiocyanates, dialkyl disulfides, and carbonyls have been developed. The isothiocyanate functional group is determined by conversion of the isothiocyanate to the substituted thiourea in an ammoniacal solution. The thiourea is desulfurized with a silver amine reagent, producing a silver sulfide precipitate. The precipitate is isolated by filtration, digested in acid, and diluted in an aqueous solution. The silver content is determined by Atomic Absorption Spectroscopy (AAS). The technique has a 0.5 - 20.0 micromole working range with a 2-4% relative standard deviation. The dialkyl disulfide is determined by reduction of the disulfide in ammoniacal sodium sulfite at 50(DEGREES). The resultant mercaptide is precipitated as the silver salt, isolated by filtration, dissolved, and determined by AAS. The technique has a 1.0 - 10.0 micromole working range with a 4-8% relative standard deviation. The carbonyl functional group was determined by treating the carboxyl with hydroxylamine hydrochloride to form the oxime product and acid. A measured quantity of ammonia was added as a proton scavenger to force the reaction to completion. The excess ammonia was determined by adding a nickel dimethyl glyoxime solution to both the sample and blank. The change in nickel concentration (from the isolated precipitate) is proportional to the carbonyl content. The nickel was determined by AAS. The technique has a working range of 1.0 - 10.0 micromoles with a 4-8% relative standard deviation. Part II: Immobilized Functional Groups For The Selective Concentration Of Trace Organics. Three different types of functional groups have been immobilized on insoluble supports for the purpose of selectively concentrating trace organics from aqueous and non-aqueous media via functional group reactions. A bis-dianilino ethane functional group was immobilized on a polyacrylate support which was selective for aldehydes in the presence of ketones. The capacity of the resin for various aldehydes was examined. The condensation product, a tetrahydroimidazole, may be acid hydrolyzed to the diamine and the original aldehyde compound. This reaction is employed to recover the sequestered compound. Several hydrazine related functional groups were examined to evaluate their utility as immobilized functional groups for carbonyl concentrating procedures. Four functional groups were evaluated. Carbazide, semithiocarbazide, acid hydrazide, and hydrazine resins were prepared. The semithiocarbazide resin was found to be the most efficient for carbonyl uptake. An isothiuronium salt was immobilized on a polystyrene backbone for the selective reaction with carboxylic acids. The resin was evaluated on the basis of batch equilibration studies, reaction kinetic studies, and column concentration/recovery studies. Solutions of 80 ppb of carboxylic acids were quantitatively recovered with a 100 fold concentration. The intent of this work was to develop novel functional group analysis techniques which may be employed at trace level concentrations.

An low-power oxygen ICP discharge has been investigated theoretically and experimentally. Temperature and flow fields have been calculated by computer simulations. The electron temperature and density, intensity ratio of ion line to atom line, and excitation temperature have been measured and compared with the LTE values. The analytical features also are evaluated. The low-power oxygen ICP discharge has been converted from a pre-running argon plasma. The torch used in the normal argon plasma is applied without modifications. The whole procedure is simplified to two steps, with a total conversion time of 1 minute. A new computer simulation method developed for an industrial plasma has been modified and applied to the analytical plasma. The two-dimensional electromagnetic field and the swirl force effect have been included in the computation. The oxygen plasma operated at the high frequency and low power now can be simulated at various operating conditions. The electron temperature for the low-power oxygen plasma has been measured and are in good agreement with the one predicted by the computer simulation. The excitation temperature has been calculated from the measurement of Boltzmann distribution of Fe I population levels and are found to be close to the electron temperature. The distribution of electron number density has been measured from the H alpha line width. The experimental results for the ratio of intensities of Ca II to Ca I and of Cd II to Cd I are in good agreement with the ones predicted by a LTE model, which confirms the oxygen plasma is close to LTE. In addition to LTE properties, the charge transfer from oxygen ions has been confirmed as an important excitation mechanism process. The detection limits for thirty eight elements have been measured and are generally 10 times poorer than in an argon plasma, but are still better than in an air or nitrogen plasma. BaO powder sample has been analyzed. A more than 10 times improvement has been observed for the signal to background ratio of Ba II line when compared to those in argon plasma.

Includes bibliographical references.

Abstract not available

Abstract not available

Abstract not available

Abstract not available

Abstract not available

Abstract not available