A bis-azo dye as a chromogenic reagent for determining traces of copper in foodstuffs, blood sera and body tissues

Department of Chemistry, M. D. University, Rohtak-124 001, Haryana, India

E-mail : ishsingh@rediffmail.com Fax : 91-1262-294133

Manuscript received 10 February 2003, revised 6 February 2004, accepted 24 August 2005

A newly synthesized bis-azo dye, 2,6-bis(l-hydroxy-2-naphthylazo)pyridine has been found to be a very sensitive and highly selective reagent for determining copper. Beer's law is followed upto 1.6 ppm with an optimum concentration range of 0.25-1.0 ppm of Cu^II Sandell's sensitivity was calculated to be 0.0012 μg cm^-2 with molar absorptivity of 5.2 x 104 dm mol^-1 cm^-1 at 570 nm. Copper has been determined with the reagent in milk, food-grains, tealeaves, human blood sera and body tissues.