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Examines the speciation of arsenic compounds using high-performance liquid chromatography at elevated temperature and selective hydride generation atomic fluorescence detection. Challenge in separating biochemically and environmentally important arsenic species; Use of ion pair chromatography; Improvement in separation efficiency with elevated column temperature.

Absolute differential cross sections for elastic p 7 Be and p 8 B small-angle scattering were measured in inverse kinematics at an energy of 0.7 GeV/u at GSI Darmstadt. The hydrogen-filled ionization chamber IKAR was used as an active target to detect the recoil protons. The projectile tracking and isotope identification were performed with multi-wire proportional chambers and scintillation detectors. The measured cross sections were analysed using the Glauber multiple-scattering theory. The root-mean-square (rms) nuclear matter radii R m = 2.42 (4) fm for 7Be and R m = 2.58 (6) fm for 8B were obtained. The radial density distribution deduced for 8B exhibits a proton halo structure with the rms halo radius R h = 4.24 (25) fm. A comparison of the deduced experimental radii is displayed with existing experimental and theoretical data. [ABSTRACT FROM AUTHOR]

The absolute differential cross section for small-angle proton elastic scattering on the proton-rich 8 B nucleus has been measured in inverse kinematics for the first time. The experiment was performed using a secondary radioactive beam with an energy of 0.7 GeV/u at GSI, Darmstadt. The active target, namely hydrogen-filled time projection ionization chamber IKAR, was used to measure the energy, angle and vertex point of the recoil protons. The scattering angle of the projectiles was simultaneously determined by the tracking detectors. The measured differential cross section is analyzed on the basis of the Glauber multiple scattering theory using phenomenological nuclear-density distributions with two free parameters. The radial density distribution deduced for 8 B exhibits a halo structure with the root-mean-square (rms) matter radius R m = 2.58 ( 6 ) fm and the rms halo radius R h = 4.24 ( 25 ) fm. The results on 8 B are compared to those on the mirror nucleus 8 Li investigated earlier by the same method. A comparison is also made with previous experimental results and theoretical predictions for both nuclei. [ABSTRACT FROM AUTHOR]

Abstract: In the present work, the differential cross sections for small-angle proton elastic scattering on the 12,14Be nuclei were measured in inverse kinematics, using secondary radioactive beams with energies near 700 MeV/u produced with the fragment separator FRS at GSI. The main part of the experimental setup was the active target IKAR, which was used simultaneously as a target and a detector for the recoil protons. Auxiliary detectors for projectile tracking and isotope identification completed the setup. The measured differential cross sections were analyzed using the Glauber multiple-scattering theory. For the evaluation of the data several phenomenological nuclear-matter density parametrizations and a sum of Gaussian parametrization were used. The nuclear-matter radii and radial density distributions of the isotopes 12,14Be were deduced. Extended nuclear-matter density distributions were observed in both isotopes, and the halo structure of 14Be was confirmed. The results were also compared with microscopic few-body and fermionic molecular dynamics model calculations concerning the structure of these neutron-rich nuclei. [Copyright &y& Elsevier]