Dual-wave β-correction spectrophotometric determination of palladium ions using neothorin

A simple low cost method has been developed and validated for the determination of trace amounts of palladium (II) ions in water and fertilizer samples. The method is based on the reaction of palladium (II) ions with the reagent neothorin (2-(2-arsonophenylazo) chromotropic acid disodium salt). The complex formed exhibits an absorption maximum at 567 nm (λmax) in Britton–Robinson (BR) buffer (pH = 2). The corrected absorbance of the formed complex at λmax was obtained by employing a β-correction spectrophotometric method. The Beer–Lambert law and Ringbom's plots of the coloured palladium reagent complex were obeyed in the concentration ranges of 0.05–2.7 and 0.1–2 μg mL−1 palladium (II) ions, respectively, with relative standard deviations in the range of ±1.3–2.1%. The limits of detection (LOD) and quantitation (LOQ) of the procedure were 0.011 and 0.04 μg mL−1 palladium, respectively. The proposed method was applied for the analysis of palladium (II) ions in spiked tap, mineral and underground water samples. The results of the developed method were satisfactorily compared with the data obtained by the inductively coupled plasma-mass spectrometric (ICP-MS) method. Statistical comparison of the results of the proposed method with those obtained by the standard method revealed no significant differences in accuracy and precision. The developed method offers a simple system coupled with good reproducibility, accuracy, ruggedness and cost effectiveness.