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Cyanide anlaysis
2002
I am doing experiment with Iron addition to 30ppm CN solution. And then I want to measure the free cyanide that is left in the solution, (not complexed with the Iron).
Can anyone tell me if I can use the Hach Method 8027 to do this? That's the Pyridine-Pyrazalone Method. I am only interested in the free cyanide concentration and not the ferro- or ferric- cyanide concentration. Does the Hach method measures free cyanide or cyanide total?
Thank you!
Susanna Li- Warren, Michigan, USA
2002
You really should be seeking help from Hach. This method analyzes free cyanide in the range 0.001 to 0.240 mg/L CN¯ (may require sample dilution on your part) so it appears suitable for your purpose; it is more difficult to analyze total CN:
"The Pyridine-Pyrazalone method used for measuring cyanide gives an intense blue color with free cyanide. A sample distillation is required to determine cyanide from transition and heavy metal cyanide complexes." --- Hach Method 8027.
Ken Vlach [deceased]- Goleta, California

Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
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