Selective separation of palladium from synthetic highly active liquid waste by cloud point extraction using benzil mono-(2-pyridyl)hydrazone and Triton X-114

A simple and rapid cloud point extraction methodology has been developed for the separation and determination of palladium, after complexation with benzil mono-(2-pyridyl) hydrazone in acidic medium, using Triton X-114 as nonionic surfactant. Under the optimum experimental conditions, the calibration curve was linear in the range of 0.05-25 µg L-1. The enrichment factor was 104 for a 50 mL sample volume. The limits of detection, based on three times the standard deviation of the blank signal by seven replicate measurements was 0.12 µg L-1. The relative standard deviation (RSD) for seven replicate determination at 5 μg L-1 of palladium was 1.85 %. Under the presence of foreign ions and EDTA as a strong complexing agent, no significant interference was observed. The accuracy of the results was verified by analyzing spiked water samples. The proposed method has been applied for the separation and determination of palladium from synthetic highly active radioactive waste with satisfactory results. (author)