Determination of Ni(II) with picolinaldehyde-4-phenyl-3-thiosemicarbazone used as a chromogenic reagent in a nonionic micellar system

Authors: AAMNA BALOUCH, MUHAMMAD IQBAL BHANGER, FARAH NAZ TALPUR, WILLIE L HINZE

Abstract: Spectrophotometric determination of Ni(II) was carried out using picolinaldehyde-4-phenyl-3-thiosemicarbazone (PAPT) as a complexing/chromogenic reagent. The possibility of using a micellar system was explored to enhance the degree of detection and allow a more sensitive spectrophotometric method for the determination of nickel ions. The anionic surfactant Triton X-100 greatly enhanced the molar absorptivity and limit of detection relative to that observed with bulk water or an organic solvent. The linear calibration graphs were obtained for 0.5-2.0 mg L^{-1} and 0.001-1.0 mg L^{-1} of Ni(II) in aqueous and surfactant media, respectively. Using this approach, the limit of detection for the PAPT-Ni(II) complex (based on 3 \sigma of blank absorbance/slope) was found to be 0.0008 mg L^{-1} with a micellar enhancement reagent. The interference from over 50 cations, anions, and complexing agents was studied at 0.50 mg L^{-1} of Ni(II); most metal ions can be tolerated in considerable amounts in aqueous micellar solutions.

Keywords: Spectrophotometry, surfactant, Ni(II), PAPT

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