Studies on Chromogenic Reaction of a New Colour Reagent 4-(2-pyridylazo)-pyrogallol and Ni (II)

The colour reaction of nickel with a new colour reagent 4-(2-pyridylazo)-pyrogallol was studied. In the pH=8.6 buffer medium, the reagent reacts with Ni( II)to form stable blue complexes, which has absorption maximium at 608 nm, with apparent molarabsorptivity of 3.05×104L·mol-1·cm-1 respectively. Beer' s law is obeyed in the range 0-0.8ug/mL solution. The proposed methods have been applied to the determination of nickel in the woman' s hair and steel with satisfactory results.