SOLID SAMPLING ELECTROTHERMAL VAPORIZATION INDUCTIVELY COUPLED PLASMAATOMIC EMISSION-SPECTROMETRY (ETV-ICP-AES) - INFLUENCE OF SOME ICP OPERATING PARAMETERS

Some parameters of solid sampling electrothermal vaporization inductiv ely coupled plasma atomic emission spectrometry (SS-ETV-ICP-AES) were investigated. The study concentrates gn the determination of Cu, Cd an d Pb. Observation height and carrier gas flow rate were optimized for different materials. Observation heights were found to be only slightl y influenced by the matrix, which however, has a large impact on the o ptimal carrier gas flow rate. Radio frequency (rf) power has little in fluence on the signal, but for a higher forward power, the plasma will tolerate a higher matrix loading. The transport relative efficiencies for pneumatic nebulization, liquid-ETV (solution-ETV) and solid sampl e ETV (SS-ETV) for different solid materials were compared. In the cas e of Cd, the transport efficiency for ETV-ICP-AES was found to be abou t 10-30 times higher than with pneumatic nebulization whereas for Cu o nly, a factor of 4 and for Pb a factor of 10 was observed. Between sol ution-ETV and SS-ETV no significant difference was found for the trans port efficiencies of Cu and Pb for different matrices, while the effic iency of the Cd transport turned out to be highly matrix-dependent.