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The translational anisotropy and angular momentum polarization of the O(2)(a (1)Delta(g),v = 0;J = 15-27) molecular photofragment produced from the UV photodissociation of O(3) in the range from 270 to 300 nm have been determined using resonance-enhanced multiphoton ionization in conjunction with time-of-flight mass spectrometry. At the shortest photolysis wavelengths used, the fragments exhibit the anisotropic vector correlations expected from a prompt dissociation via the (1)B(2) <--(1)A(1) transition. Deviations from this behavior are observed at longer photolysis wavelengths with, in particular, the angular momentum orientation showing a significant reduction in magnitude. This indicates that the dissociation can no longer be described by a purely impulsive model and a change in geometry of the dissociating molecule is implied. This observation is substantiated by the variation of the translational anisotropy with photolysis wavelength. We also observe that the bipolar moments describing the angular momentum polarization of the odd J states probed are consistently lower in magnitude than those of the even J states and that this variation is observed for all photolysis wavelengths.

The complicated analytical challenge of lead determination in the presence of high levels of copper, has been investigated using anodic and cathodic stripping voltammetry, on a variety of mercury free electrode substrates. CSV was found to be ideally suited towards lead determination in a predominantly copper matrix, due to the lack of interference from copper ions on the anodic electrochemistry of lead. A CSV technique, incorporating the use of power-ultrasound and a borondoped diamond electrode is presented. The sono-CSV technique has been optimised to give a lower limit of detection of aqueous Pb 2+ ions of 1.6×10 -9 M for a 300 s PbO2 deposition, requires no solution degassing, is mercury-free and totally free from copper-intermetallic interference. As an extreme example, the technique was applied successfully to the determination of lead content of a copper-lead alloy, after a simple acid digestion protocol. Excellent correlation was observed between the known lead level and experimental results, with the technique being sensitive towards the detection of 3.3×10 -4 % (w/w) lead in copper, for the analysis of a 10 mg sample.

The sonochemically facilitated, mercury free detection of Pb2+ at a copper electrode has been investigated as a means of simplifying the quantification of this important analyte and to minimise the interference of copper ion. The procedure relies upon maximising the formation of Pb-Cu intermetallic compounds leading to the emergence of a single, easily quantifiable stripping signal. Linear responses to Pb2+ were obtained with a sensitivity comparable to that obtained at a bare glassy carbon electrode. Interference from Cu2+, Zn2+ and Cd2+ was assessed on the copper electrode with no appreciable change in the Pb2+ voltammetric profile observed. In contrast, bare glassy carbon showed a significant change in Pb2+ voltammetric profile as Cu2+ was added, due to the formation of intermetallic species.