Using a coupling of ICP with a closed electrolyte cathode discharge (ELCAD) cell as nebulizer unit it was possible to observe a well defined element dependency of the cathode sputtering process on the electrolyte surface. Investigating the ICP signal ratio referred to the pneumatic nebulization, the ELCAD sputtering produces about three times higher mass transport for Al, Cr, Pb and Cd than for Mg and Cu. B, Ba and Ca have an even lower signal while Hg shows a "super-sputtering" effect, having a 17 times higher signal with ELCAD than with pneumatic nebulization. Assuming that positively charged particles are forced back to the cathode by the 107 V m-1 field in the cathode dark space these observations fit to the model of stepwise charge neutralization by hydrolysis in the vapor-phase, which process is known in mass spectrometry. The sputtering process in the ELCAD can be described with a four-zone kinematic model of the cathode dark space.
ASJC Scopus subject areas
- Analytical Chemistry