Applicable Samples : Polymers and Electronics

Weigh a small amount of sample in a beaker.

Add 50 ml of solution ( Magnesium Chloride in 1M Phosphate buffer ).

Heat mixture on a water bath at 90-95oC with constant stirring for atleast 3 hours.

Cool mixture to room Temperature with constant stirring.

Filter thru a 0.45 microns filter paper.

Adjust filtrate to appropirate pH using Nitric acid.

Transfer 95 ml of this solution to a 100ml volumetric flask.

Filter thru a C18 syringe if it becomes turbid or develops precipitate.

Add diphenylcarbazide.

Adjust to approprite pH using Sulfuric acid then dilute to the mark.

Invert several times to mix.

Let stand for 5 to 10 minutes for full color development.

Read absorbance of solution at 540 nm using 1 cm cuvette.

Read absorbances of atleast 3 the standard solutions of Chromium 6+.

Prepare calibration curve from absorbance readings of standard solutions against their corresponding concentrations.

Calculate the Hexavalent Chromium content using Linear regression.

Related Posts :
US EPA 3060A – Hexavalent Chromium Testing Method & Procedure
EN 71 Part 3 ( Testing Procedure )
IEC 62321 – Lead, Cadmium & Mercury Testing Method & Procedure
Hexavalent Chromium ( Cr6+) in Water
ASTM F963 -96a / ASTM F963 -07 (Testing Procedure)