The use of solid-phase extraction and direct injection of a copolymer sorbent as slurry into the graphite furnace prior to determination of cadmium by ETAAS

Abstract

Cadmium in different certified materials was determined by direct injection of sorbent loaded with the analyte into the graphite furnace of electrothermal atomic absorption spectrophotometer. For this purpose, cadmium was collected on ethylene glycol dimethacrylatemethacrylic acid copolymer treated with ammonium pyrolidine dithiocarbamate by the batch technique. After separation of liquid phase, slurry of the sorbent was prepared for the direct injection of the sorbent into graphite furnace. Optimum conditions for quantitative sorption and those for preparing homogeneous and durable slurry were investigated. A 100-fold enrichment factor could be reached. Cadmium in certified sea water and bovine liver samples was determined within the 95% confidence limits. The proposed technique is fast and simple, and the risk of contamination is low. The calculated detection limit for cadmium using sample-matching blanks was 0.09 µg L⁻¹ according to the 3σ concept for the described method.

Keywords:

• Separation
• Preconcentration
• Cadmium
• Electrothermal atomic absorption spectrometry
• Slurry sampling