10.22376/ijpbs.2019.10.1.p1-12 Volume 3 Issue 4 2012(October - December) Acetophenone 2',4'-dihydroxy semicarbazone (A24DHS) as a photometric reagent for the extractive spectrophotometric determination of Molybdenum (VI) is presented in this paper. The reagent A24DHS gave instantaneous and stable yellow colour with Molybdenum (VI) in the pH range 1.6 to 2.4. The system obeys Beer's law in the concentration range of 1.0 µg/mL to 8.0 µg/mL at 370 nm. The Limit of Detection (LOD) is calculated by using standard deviation of blank solution at confidence limit 98.3%, which is found to be 0.315 µg / mL. The stoichiometry of the complex is established as 1:3 (M:L) by Job's method of continuous variation and confirmed by mole ratio method. The standard deviation and the coefficient of variance are presented. The results of the prescribed procedure applied for the determination of the micro amounts of Mo (VI) in standard steel samples, alloys, pharmaceutical and synthetic samples are presented. D. K. YADAV, R. S. LOKHANDE, SHIRISH PITALE, S.P. JANWADKAR,P.S. NAVARKAR AND P.K. RANA Molybdenum, Spectrophotometric determination, n-Butanol, Acetophenone 2’, 4’- dihydroxy, semicarbazone derivative. 309-314