Determination of Pd(II) content in catalysts and tap water samples via photoacoustic spectroscopy analysis of Pd(II)-3-[2'-thiazolylazo]-2,6-diaminopyridine complex on solid phase.

In this work a simple method for the determination of Pd(II) by photoacoustic spectroscopy (PAS) is introduced. The method is based on Pd(II) colorimetric reaction with immobilized 3-[2(')-thiazolylazo]-2,6 diaminopyridine (2,6 TADAP) retained in a cationic resin Dowex 50W X4 20/50. The immobilization of Pd(II) on solid phase is combined with PAS. The Pd(II) concentration was determined by conventional photoacoustic measurement in the range of 625-645 nm. The calibration for Pd(II) was linear over the range 12-210 microg L(-1). The obtained analytical features were LOD 4 microg L(-1) and LOQ 12 microg L(-1). The relative standard deviation of the method was <5%. The proposed method has been successfully tested in determination of leachable Pd in disposed catalyst and in spiked samples of tap water. In the introduced method, complicated preparatory steps became simple, inexpensive, and it is suitable for applications in environmental samples. Results obtained by PAS agree with those obtained by using conventional FAAS. The figures of merit in this method make it an attractive alternative to UV-vis and FAAS.