SIMULTANEOUS SPECTROPHOTOMETRIC DETERMINATION OF Ni(II) AND Zn(II) IN WASTE WATER BY H-POINT ADDITION STANDARD METHOD USING 5-BROMOSALICYLALDEHYDE THIOSEMICARBAZONE

摘要

Optimized and validated spectrophotometric method has been proposed for the determination of nickel and zinc simultaneously. 5-bromosalicylaldehyde thiosemicarbazone (5-BSAT) reacts with nickel(II) and zinc(II) to form [Ni(II)-(5-BSAT) 2 ] and [Zn(II)-5-BSAT] complexes, respectively. The maximum absorbance of these complexes was found at 378 nm and 381 nm, respectively. For [Ni(II)-(5-BSAT) 2 ], Beer’s law is obeyed over the concentration range of 2.0×10 -6 M – 6.0×10 -5 M with molar absorptivity, ε of 0.92×10 4 L.mol ?1 .cm ?1 . [Zn(II)-5-BSAT] complex obeys Beer’s law in 2.0×10 -6 M – 6.0×10 -5 M range with molar absorptivity, ε of 1.08×10 4 L.mol ?1 .cm ?1 . A simultaneous spectrophotometric H-point standard addition method (HPSAM) is proposed for the determination of these metals. The proposed method is successfully employed in the analysis of waste water sample for the determination of nickel and zinc content.