| Abstract: | A laser-induced fluorescence in graphite furnace (LIF-GF) set-up has been equipped with an intensified CCD detector (ICCD) that enables simultaneous multichannel detection of large wavelength regions. The main advantages of such a system in comparison with conventional photomultiplier detection are: simultaneous detection of several fluorescence wavelengths for easy characterization of excitation and fluorescence spectra and for an increase of the absolute sensitivity and spectral selectivity; simultaneous monitoring of background signals, such as those due to matrix interferences, blackbody radiation and scattered laser light; decrease of the susceptibility to radio-frequency pick-ups emitted from the pump laser due to the delayed read-out procedure; time-resolved studies of fluorescence spectra for improved elemental selectivity or for studies of atomization processes, and a possibility to perform two-dimensional imaging of height distributions of atomization and, in combination with an imaging spectrometer, diffusion processes in the furnace. The first work on LIF-GF with ICCD detection has been performed on Ni. The most sensitive and versatile excitation and detection wavelengths have been identified. Detection limits in water solutions by the LIF-GF technique have been improved by two orders of magnitude and are found to be 0.015 pg with ICCD and 0.01 pg using a photomultiplier at the most sensitive excitation and detection wavelengths. Nickel in concentrations has been detected in aqueous standard reference samples with sodium concentrations ranging from to % (riverine water and estuarine water) with good accuracy and precision. The Ni contents of standard riverine and estuarine water were determined to 1.00 ± 0.11 and 0.75 ± 0.07 ng/ml, respectively. The certified concentrations are 1.03 ± 0.10 and 0.743 ± 0.078 . |
