The effect of palladium modifier on the efficiency of antimony hydride trapping in graphite furnace atomic absorption spectrometry (AAS)

The performance of palladium as permanent chemical modifier electroplated on the surface of a graphite tube for the preconcentration of antimony hydride was examined and compared with thermally formed Pd-coatings. The application of Pd-electroplated tubes allows to perform at least 75 determination cycles without any significant change in the efficiency of hydride collection. This is an advantage over the thermally formed palladium coating which must be obtained individually before each measurement. After the optimization of the system parameters a concentration detection limit of 48 ng/L and an absolute detection limit of 71 pg for a 1.48 mL sample were obtained. The procedure was applied to the determination of antimony at a concentration level of 0.2 μg/L in a tap water sample.