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 buflbr medium, the reagent reacts with Ni(Ⅱ)to form stable blue complexes, which has absorption maximium at 608 um, with apparent molarabsorptivity of 3.05 ×104L ·mol-l ·cm-l respectively. Beer's law is obeyed in the range 0-0.8sug/mL solution. The proposed methods have been applied to the determination of nickel in the woman's hair and steel with satisfactory results.