摘要:There are many difficulties for estimating cyanide ion in actual analysis of the industrial waste water. A new analytical procedure has been designed to use a cyanometer in colorimetry. The use of cyanometer simplifies the steps in analysis, though dat a obtained from the direct use of cyanometer to waste water samples are unreliable. The stability of pyridine-pyrazolone reagent in colorimetry was examined and it was found that the mixed reagent solution should not be preserved for more than one day. It has become obvious that chlorine, sulfide, and sulfite ions have some effect on cyanide ion, the reagents for colorimetry, and conditions of a cyanometer.