Extractive Spectrophotometric Determination of Chromium (Iii) With P-Methylisonitrosoacetophenone

R. S. Lokhande¹*, Mamta Makhijani¹ and V. D. Barhate²

¹Inorganic Chemistry Laboratory, University of Bombay, Vidyanagari, Bombay- 400 098 (India) ²V.E.S. College of Arts, Science and Commerce, Sindhi Society, Chembur, Mumbai- 400 071 (India)

p-Methylisonitrosoacetophenone (HIMAP) extracts Cr(III) quantitatively (99.25%) into chloroform from an aqueous solution of pH 4.5-7.0 after digestion on boiling water bath for 30-40 min. The chloroform extract shows an intense peak at 430 nm (lmax). Beer's law is obeyed over the Cr(III) concentration range 0.1-10 μg/ml. The molar absorptivity is 8056 L mole-1 cm-1 at 430 nm. The composition of extracted species is found to be 1:3 (Cr:HIMAP) by Job's continuous variation and mole ratio methods. The interference by various ions has been studied. The proposed method has applied to determination of Cr(III) in Cr-catalyst sample.

Chromium (III); p-Methylisonitrosoacetophenone