Extractions with long-chain amines-VIII Colorimetric determination of chromium(VI) with diphenylcarbazide.
Traces of chromium(VI) are extracted from sulphuric acid solution into a chloroform solution of trioctylmethylammonium chloride. After the addition of solid diphenylcarbazide to the separated organic phase, a red colour is developed and is measured spectrophotometrically at 550 nm. A great number of common metals, including iron and copper, do not interfere when present in ratios up to at least 1:40,000 (chromium: metal).
Adam
J
J
Analytical Laboratory Institute of Geological Sciences Charles University, Prague 2, Czechoslovakia.
Pribil
R
R