Synthesis of 5-hydroxy-2-sulfo-4'-nitrophenyl-diazoaminoazobenzene and its color reaction with nickelII

A new triazene reagent 5hydroxy-2-sulfo-4'-nitrophenyl-diazoaminoazobenzene(HSDAAN) has been synthesized and the color reaction conditions of HSDAAN with nickel? have been studied.In the buffer solution of Na_2B_4O_7-NaOH at pH 10 and in the presence of TritonX-100,the color reagent reacts with nickel? to form a red complex(2∶1).The maximum absorption wavelength of the complex is at 528 nm,and the apparent molar absorptivity is 2.52×10~5 L·mol~-1·cm~1.Beer's law is obeyed in the range of 0-15 μg/25 mL for nickel?.This method has been used for the determination of nickel in aluminum alloy samples with RSD of 2.7%-4.3%(n=5)