Determination of molybdenum in human urine by spectrophotometric method using thiazolylazo compounds as chromogenic reagents

Four azo compounds based on diazotization of 2-aminobenzothiazole have been synthesized and characterized by elemental analysis as well as different s pectroscopic techniques. The potentiality of the prepared compounds as new chromogenic reagents for the spectrophotometric determination of Mo6+ was s tudied by extensive investigation of optimum conditions favouring the forma tion of the coloured complexes. Beers law is obeyed in the concentration ra nge 0.2-8.5 mu g ml(-1) whereas Ringbom optimum concentration range was 0.8 -7.5 mu g ml(-1). The detection limit was 0.05 mu g ml(-1). The molar absor ptivity and Sandell sensitivity of the formed complexes are calculated. The effect of interfering ions on the determination of Mo6+ was investigated. The relative standard deviations for six replicate determinations of 5.0 mu g ml(-1) of Mo6+ are 1.23, 1.47, 1.05 and 1.38 % using reagents I, II, III and IV, respectively. The proposed method has been applied to investigate the amount of Mo6+ in human urine samples. The molybdenum levels found betw een 0.5-2.1 mu g/100 ml.