Preconcentration of ruthenium on activated carbon impregnated with 2,4,6-tri-2-pyridyl-1,3,5-triazine/graphite furnace AAS

Ruthenium is adsorbed on activated carbon impregnated with 2,4,6-tri-2-pyridyl-1,3,5-triazine (TPTZ-AC). A simple and rapid determination method for trace amounts of Ru by graphite furnace AAS using direct heating of Ru adsorbed TPTZ-AC was investigated. The proposed method is as follows. A sample solution of 100-1000 cm3 containing Ru is mixed with 50 mg of TPTZ-AC. The pH is then adjusted to 7.0 with phosphate buffer solution, and stirred for 10 min. The Ru adsorbed TPTZ-AC was separated from the sample solution by filtration. The TPTZ-AC on membrane filter is dispersed in 5.0 cm3 water. After shaking, 10 μl of the resulting suspension is injected directly into the graphite furnace. The absorbance is measured at 349.9 nm. The pyrocarbon treated graphite tube was most effective for the measurement of Ru. The calibration curve was liner below 2.5 μg/100 cm3 (aqueous phase). The determination limits (3σ) were 0.08 μg/100 cm3 (aqueous phase). The presence of such as Cu, Ni did not interfere. Interference by Fe could be masked by adding thiourea and 1,10-phenanthroline and ammonium fluoride. The proposed method was applied to the determination of Ru in several water samples. (author)