Non-extractive spectrophotometric determination of ni(ii) in plant samples using salicylaldehyde isonicotinoylhydrazone

A very simple, highly selective and non-extractive spectrophotometric determination for the trace amounts of nickel (II) has been developed. Salicylaldehyde isonicotinoylhydrazone (SAINH) has been proposed as a new analytical reagent for the direct non- extractive spectrophotometric determination of nickel (II). The reagent reacts with nickel in an basic medium (pH 7.5, sodium acetate and acetic acid ) to form a yellow coloured 1: 1(M : L) Complex. The reaction is instantaneous and the maximum absorption was obtained at 385 nm and remains stable for 1h. The molar absorptivity and sandell’s sensitivity were found to be 1.81 x 104 L mol-1 cm-1 and 0.32 µg cm-2 respectively. Linear calibration graphs were obtained for 1.0 -10.0 µg/ml of nickel (II). The method is highly selective for nickel and successfully used for the determination of nickel in several plant samples.