Selective and sensitive extractive spectrophotometric determination of micro amounts of palladium(II) in spiked samples: using a new reagent N-ethyl-3-carbazolecarbaxaledehydethiosemicarbazone

N-Ethyl-3-cabazolecarboxaldehydethiosemicarbazone (ECCT) is proposed as a new, sensitive and selective complexing reagent for the separation and extractive spectrophotometric determination of palladium(II) at pH: 4.0 to form a yellowish orange colored 1:1 chelate complex, which is very well extracted in to n-butanol. The absorbance was measured at a maximum wavelength, 410 nm. This method obeys Beer’s law in the concentration range 0.0–6.6 μg mL⁻¹ and the correlation coefficient of Pd(II)-ECCT complex is 0.998, which indicates an excellent linearity between the two variables with good molar absorptivity and Sandell’s sensitivity, 1.647 × 10⁴ l mol⁻¹cm⁻¹, 6.49 × 10⁻³ μg cm⁻², respectively. The instability constant of complex calculated from Edmond’s method, 2.724 × 10⁻⁵ was in good agreement with the value calculated from Asmus’ method 2.624 × 10⁻⁵, at room temperature. The precision and accuracy of the method is checked with calculation of relative standard deviation (n = 5), 0.839. Edmond’s method was observed to be a more selective method in the presence of EDTA, oxalate and phosphate ions. The method was successfully applied for the determination of Pd(II) in water samples, synthetic mixtures and hydrogenation catalysts, employing an atomic absorption spectrometer for comparing these results.