Cloud point extraction for the preconcentration of palladium and lead in environmental samples and determination by flow injection flame atomic absorption spectrometry CPE for preconcentration of Pd and Pb by FI-FAAS

摘要

Purpose An online cloud-point extraction (CPE) coupled with flow injection method is developed for the separation and preconcentration of palladium and lead from various matrices using flame atomic absorption spectrometry (FAAS). Method The method employs the formation of complexes of the metallic species with dimethylglyoxime, which are subsequently entrapped in the micelles of the surfactant Triton X-114, upon increase of the solution temperature to 60°C and loaded into the flow injection system at a flow rate of 4.6 mL min~(-1). The surfactant rich-phase was retained in a minicolumn packed with animal wool at pH 6 and eluted with 1.0 mol L~(-1) nitric acid in methanol at a flow rate of 1.1 mL min~(-1) directly into the nebulizer of the FAAS. The CPE variables and flow injection conditions affecting the analytical performance of the combined methodology was studied and optimized.