LaMotte AM-21 Water Pollution Detection Outfit - Manual (Page 28)

Procedure
WARNING: This cyanide test is a field test designed to screen samples for
the presence of cyanide. Oxidizing agents, as well as certain metal complexes
formed with iron, copper, manganese and platinum, may produce a false
positive result. All positive tests for cyanide should be verified or confirmed
by an independent laboratory using the appropriate procedures given in the
most recent edition of Standard Methods for the examination of Water and
Wastewater.
1. Fill test tube (0804) to the upper line marked “A” with the sample water.
2. Add two drops of *Cyanide Reagent #1 (7388). Cap and mix. Add two
drops of *Cyanide Reagent 2 (7389). Cap and mix. If a precipitate forms,
filter the solution into the second test tube (0804) until the tube is filled
to the line marked “B.” A pink color indicates the presence of Cyanide.
3. Rinse the first test tube carefully and then fill it to the line marked “B”
with deionized or cyanide-free tap water.
4. Add two drops of *Cyanide Reagent #2 (7389) to the deionized or
cyanide-free tap water sample and mix the contents.
5. Add *Cyanide Reagent #3 (7390) to the distilled water sample test tube
(from step 4) one drop at a time until the color of the liquid matches the
color of the test sample (from step 2). Match the colors by looking down
through the test tubes held about a half inch above a plain white surface.
Count the number of drops of *Cyanide Reagent #3 (7390) that were
required to match the color of the test sample. Each drop of *Cyanide
Reagent #3 (7390) added is equal to 0.05 ppm Cyanide.
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