A direct spectrophotometric method for the determination of mercury in environmental and biological samples using p-carboxybenzenediazoaminobenzene-p-azobenzene

School of Studies m Chemistry, Pt Ravishankar Shukla University, Raipur-492 010, Chhattisgarh, India E-mail debmanas@yahoo com Manuscript received 26 October 2005, accepted 6 April 2006 A very sample, sensitve and highly selective spectrophotometric method for the determination of mercury in biological and envioronmental samples described herewith is based on the formation of orange coloured species of HgII with \(p\)-carboxybenzediazoaminobenzene \(p\)-azobezene (CDABAB) and a non-ionic surfactant TX-100 over pH range 9.4-10.6. The orange colord HgII-(1X-100)-(CDABAB) complex m aqueous medium shows maximum absorbance at 510 nm with molar absorptivity value of 7.9 x 104 dm3 mol-1 em-1. The detection limit of the method is 6 ng ml-1 The system obeys Beer's law up to 2.0 μg HgII ml-1 in aqueous phase. The repeatabihty of the method has checked by finding relative standard deviation (RSD, \(n\) = 10) value for solutions cach contaning 1.0 μg HgII ml-1 and RSD value of the method was found to be 1.5%. The validity of the method has been satlisfactory exammed for the determination of mercury in biological and environmental samples. The RSD value for the actual analyte content ranged between 2.1 to 2.7%