The analytical measurements were made with a simultaneous
Perkin-Elmer ICP OES, model Optima 3000DV (Norwalk, CT, USA),
equipped with a peristaltic pump, a cross-flow nebulizer coupled
to a Scott camera and a ceramic injector tube with 2.0 mm internal
diameter. This instrument has a solid-state segmented array
charge coupled device (SCD) detector and can operate in both
radial and axial torch configurations. In this work, the axial viewing
mode was employed and the cool plasma recombination area was
stripped off with a shear gas interface. The entire system was
controlled with PE Winlab software. The instrumental conditions
used are presented in Table 1.