SEOH Analytical Test Strips for the Determination of Chroumium

This test paper shows violet spots on a white background upon application of solutions containing chromium. The reaction is based on the presence of chromium as chromate. Cr 3+ ions must be converted to chromate. Interferences caused by mercury salts or molybdates are readily circumvented. Limit of sensitivity: 2 mg/l Cr 3+ corresponding to 5 mg/l CrO 4 2ûNote: Non-destructive tests for the detection of chromium in metal alloys are carried out as follows: Apply a drop of a proper acid solution (1 part hydrochloric acid 37 % + 4 parts hydrogen peroxide 3 %) to the degreased steel surface, wait 10 û 30 seconds, add some drops of sodium hydroxide solution and cover the precipitate with filter paper. Press the chromium test paper on top of the filter paper. In the presence of chromium, a violet spot appears when the test paper is bathed in dilute sulphuric acid.Limit of sensitivity: 0.1 % Cr