A custom echelle/CCD spectrometer system has been employed for equilibrium and nonequilibrium excitation measurements in the high-voltage spark discharge. By exploitation of the large spectral information bandwidth of the echelle/CCD system, multiple ionization stages of argon were observed in the spark emission spectrum. Ion-to-atom emission intensity ratios were used in a linearized form of the coupled Saha-Boltzmann equation for the determination of both electron temperature and density. Nonequilibrium conditions were considered. The dependence of argon excitation on sample matrix was also explored.

An echelle spectrometer has been constructed, which is optimized for use with a charge-coupled array detector, with dispersion and resolution appropriate for elemental analysis and plasma diagnostics. Design considerations, characterization, software, and initial experimental data are reported.

To fuel clinical development of the experimental CNS medicine LY2140023, we developed a scalable route for the multistep synthesis of a pivotal synthetic intermediate. The core of the conformationally restricted glutamic acid-based amino acid analogue was built via a Rh-catalyzed cyclopropanation of thiophene. Regioselective functionalization of the remaining double bond was achieved by a hydroboration/oxidation sequence followed by a BuchererÀBergs reaction to give a hydantoin with the targeted L-glutamic acid configuration. Subsequent resolution, oxidation state, and protecting group manipulations gave the key intermediate in an overall nine-step scalable streamlined route starting from thiophene.

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The matrix dependence of analyte excitation in the high-voltage spark discharge has been investigated. The analyte excitation distributions of Fe(I), Mo(I), and Cu(I) have been measured. The large wavelength range of a custom echelle/CCD system was exploited for these determinations. The analyte excitation within the high-voltage spark on a time-integrated basis was determined to be independent of both sample matrix and sampled species.