ABSTRACT
Objective To explore an easy, rapid and suitable method for determination of cyanide with lower concentration in quality_controlled water sample. Methods To overcome the shortcomings in determination of low concentration cyanide in water by iso_niacin_pyrazolone spectrophotometry and pyridin_barbituric acid spectrophotometry, the iso_niacin_barbituric acid spectrophotometry was studied for determining the lower concentration cyanide in water, the data obtained were compared with those obtained from the standard method iso_niacin_pyrazdone spectrophotometry. Results The results showed no statistically significant differences between these two methods. The precision, accuracy and other indexes all accorded with the analysis criteria. Conclusion The iso_niacin_barbituric acid spectrophotometry was easier to operate, more rapid and lower cost, the conditions of colorimetry were easier to be controlled compared with those of iso_niacin_pyrazolone spectrophotometry.