Test Procedures
APPLICATION:
Low level concentrations in drinking and surface waters;
domestic and industrial waters. This method determines only
those cyanides amenable to chlorination.
RANGE:
0.00–0.50 ppm Cyanide
MDL:
0.05 ppm
METHOD:
Cyanides react with a chlorine donor to form cyanogen
chloride, which subsequently reacts with Pyridine
and Barbituric Acid to form a red-blue compound in
proportion to the amount of cyanide originally present. The
concentration of the red-blue compound is determined
spectrophotometrically.
SAMPLE HANDLING &
PRESERVATION:
Cyanide solutions tend to be unstable and should be
analyzed as soon as possible. Samples can be stabilized by
adjusting the pH to greater than 12 with NaOH. However, the
pH will have to be readjusted to pH 10.5 before performing
the test.
INTERFERENCES:
Oxidizing agents and aldehydes can react with cyanide, while
reducing agents, such as sulfi te, react with the chlorine
donor; both can cause negative interferences. Thiocyanate
and cyanogen chloride both react as cyanide in this test and
will give a positive interference. Color and turbidity can also
interfere.
CYANIDE
SMART Spectro 2 Test Procedures 05.02.16
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