The spectrophotometric determination of the purity of commercial dithizone and the purification of small amounts of the reagent by chromatography

Abstract

The purity of commercial dithizone is determined quantitatively by comparing the optical density of a solution at wavelength 620 nm with that of a pure sample. Qualitatively, the purity is estimated from the pattern obtained by chromatographing the crude dithizone on Whatman SG81 (silica-impregnated) paper.

Small amounts of the pure reagent are separated by chromatography on large sheets of Whatman SG81 paper or on a column consisting of a mixture of equal parts of acid-washed silica gel (Kieselgel N) and Celite 545, with benzene as eluting agent.