Direct and derivative spectrophotometric method for the determination of nickel(II) with 2,4-dihydroxy benzaldehyde isonicotinoyl hydrazone

Department of Chemistry, Sri Krishnadevaraya University, Anantapur-515 003, Andhra Pradesh, India

Manuscript received 1 April 2004, revised 27 October 2005, accepted 28 November 2005

A simple and sensitive spectrophotometric method has been developed for the determination of nickel(ll) in aqueous medium.The metal ion forms an yellow coloured soluble complex with 2,4-dihydroxy benzaldehyde isonicotinoyl hydrazone (2,4-DHBINH) at pH 6.0 with λ_max at 400 nm. Beer's law is obeyed in the range of 0.059-1.17 μg ml-1 of Ni^II. The molar absorptivity and the Sandell's sensitivity of the method are 4.00 x 10⁴ L mol^-1 cm^-1 and 0.0015 μg cm^-2 respectively. The interference of various diverse ions has been studied.The complex has a 1 : 1 [Ni^II : 2,4-DHBINH] stoichiometry. A method for the determination of nickel(II) by first order derivative spectrophotometry has also been proposed.