[The study of the colour reaction of new reagent N-nonyl-N'-(sodium p-aminobenzenesulfonate) thiourea (NPT) on Pd(II) and its application].

In this work, the colour reaction of Pd(II) on water-soluble spectrophotometric reagent N-Nonyl-N'-(Sodium p-Aminobenzenesulfonate) thiourea (NPT) which is newly synthesized has been studied. The result indicates that Pd(II) reacts on NPT form a yellow water-soluble complex with the proportion of 1:4 in HAc-NaAc buffer solution at pH5.8-6.6. The presence of CTMAB makes a synergistic sensitizing effect on the reaction,the complex exhibits a maximum absorption wavelength at 297.6nm, apparent molar absorptivity epsilon97.6 = 1.27 x 10(5) L x mol(-1) x cm(-1). Beer's law is obeyed when concentration of Pd is within the range of 2-11.2 microg/25 mL, 50 kinds of ions do not influence the determination. It shows NPT is one of the best reagents on its sensitivity and selectivity in the determination of Pd(II). This method obtains satisfying result when using in the determination of Pd in anode mud and catalyst.