Abstract
Simple preconcentration step was developed for cadmium determination after chemical vapor generation prior to atomic absorption spectrometric detection. Chemical vapor generation of cadmium was performed in the presence of Cr3+/KCN as modifiers. The vapor generation system was connected to the quartz modular trap-andatomizer device allowing for direct analyte preconcentration in the independently heated inlet arm of this device. Gold amalgamators or nanoparticles were tested as preconcentration surfaces. Efficient cadmium trapping was observed on gold amalgamators followed by unsuccessful analyte release. Key-parameters were optimized for gold nanoparticles including the temperature of trapping (200 °C) and volatilization (900 °C) steps, the carrier gas composition and its flow rate as well as the amount of gold nanoparticles (8 μg Au). Limit of detection reached in this arrangement was 13 pg mL-1 Cd, being approximately 5-times better than in the mode without any preconcentration.
The efficiency of cadmium preconcentration step with gold nanoparticles was estimated to 70%.