Spectrophotometric determination of molybdenum after separation by the adsorption of its trifluoroethylxanthate on naphthalene

Abstract

Molybdenum reacts with potassium trifluoroethylxanthate to form a water-insoluble complex in the acid concentration range 0.1–3 M, pH 1.0–3.5. This complex is easily adsorbed on to microcrystalline naphthalene from an acetone solution and absorbs in the range 360–370 nm. Beer's law is obeyed over the concentration range 5.0–75.0 µg of molybdenum in 10 ml of chloroform solution. The molar absorptivity and Sandell sensitivity are 1.041 × 10⁴ l mol^–1 cm^–1 and 0.0092 µg cm^–2, respectively. Ten replicate analyses of a sample solution containing 30 µg of molybdenum gave a mean absorbance of 0.325 with a relative standard deviation of 0.60%. The interferences of various ions were studied and conditions were developed for the determination of molybdenum in some alloy samples.