Cyanide
Cyanide
Page 2 of 4
Cyanide_UniCell_Other_PPZ_Eng_Ody.fm
Interferences
Interferences are caused by substances like formaldehyde which react with the
cyanide. Reducing agents (like sulfite) and other compounds that affect the
reactivity of chlorine also interfere. Thiocyanate and cyanide react similarly with
chlorine to form cyanogen chloride, thus the thiocyanate will be a positive
interference in the test.
Sample Collection, Preservation, and Storage
Samples collected in glass or plastic containers should be analyzed as quickly as
possible. Preserve the sample by adjusting the pH higher than 12 by adding
5.0 N Sodium Hydroxide Standard Solution (4 mL per 1000 mL). Store the
samples at 4 °C (39 °F) or less.
5. Pipet 2 mL of
Pyridine-hydrochloric
acid B (HCT 129 B) into
the sample vial.
Recap the vial. Invert
several times to mix.
6. Touch the timer icon.
Touch
OK.
An 8-minute reaction
period will begin.
After the reaction period,
invert the sample vial
again to mix completely.
7. Install the 16-mm cell
adapter.
Note: See Section 2.6 Sample
Cell Adapters in the Instrument
Manual for adapter installation
details.
When the timer beeps,
wipe the zero vial (white
cap) and place it into the
cell adapter.
8. Touch Zero.
The display will show:
0.00 mg/L CN
–
Underrange
9. Wipe the sample vial
and place it into the
celladapter.
10. Touch Read.
Results will appear in
mg/L CN
–
.
Zero
Read
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