Extraction of ultra-traces of lead, chromium and copper using ruthenium nanoparticles loaded on activated carbon and modified with N,N-bis-(alpha-methylsalicylidene)-2,2-dimethylpropane-1,3-diamine

We describe a novel adsorbent for effective extraction of lead(II), chromium(III) and copper(II). It consists of ruthenium nanoparticles loaded on activated carbon that were modified with N,N-bis-(alpha-methylsalicylidene)-2,2-dimethylpropane-1,3-diamine. The sorbent was applied to solid-phase extraction combined with ionic-liquid based dispersive liquid-liquid microextraction method. The effects of parameters such as amounts of adsorbent, type and volume of elution solvent, type and volume of extraction and dispersing solvents, etc. were evaluated. The ions were then quantified by flame atomic absorption spectrometry. Under the best conditions, limits of detection, linear dynamic ranges and enrichment factors for these ions ranged from 0.02 to 0.09 mu g L-1, 0.08 to 45 mu g L-1 and 328 to 356, respectively. The results showed that the method, in addition to its sensitivity, selectivity and good enrichment factor, is simple and efficient. It was applied to the determination of the three ions in blood plasma, food (broccoli, coriander and spinach), and in (spiked) samples of tap, spring and river water.