LaMotte AM-21 Water Pollution Detection Outfit - Manual (Page 23)

Chromium (Chromate) Test
Chromium may be present in water containing waste from industry such as
the plating industry. It is considered to be a toxic chemical, and if present in
an amount of over 0.5 ppm it is evidence that contamination is from
untreated or incompletely treated waste. This calls for more careful waste
disposal control by the offending plant. It is determined colorimetrically by a
reaction with diphenylcarbohydrazide in acid solution to produce a pink or
red color.
Field Test Method
Quantity Contents Code
30g *Chromate Indicator Powder *4431-G
1 Spoon, 0.5 g 0698
1 Test Tube, 5.0 mL 0230
1 Chromate Comparator, 0.5 and 2.0 ppm 7484
WARNING: Reagents marked with a * are considered to be potential health hazards.
To view or print a Material Safety Data Sheet (MSDS) for these reagents see MSDS CD
or www.lamotte.com. To obtain a printed copy, contact LaMotte by email, phone or fax.
Procedure
1. Fill test tube (0230) to the 5 mL line with the sample water.
2. Use the 0.5g spoon (0698) to add one level measure of the Chromate
Indicator Powder (4431) to the water sample. Mix until the powder is
dissolved. Wait two minutes for color development.
3. Insert the test tube in the Chromate Comparator (7484) and compare
the color of the test sample with the colors of the color standards.
The readings on the comparator are in terms of Sodium Chromate. To
convert Sodium Chromate reading to Hexavalent Chromium, multiply the
comparator value by 0.32.
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