Abstract: Objective To establish a rapid and efficient method for the detection of cyanide in urine with continuous flow inject analysis by diluting alkaline hydrolysis with sodium hydroxide solution,analyze the effects of dilution ratio,sodium hydroxide solution concentration,and alkaline hydrolysis method on the determination of cyanide in urine. Methods After refrigerated centrifugation,the urine samples were diluted with a suitable concentration of sodium hydroxide solution to an appropriate multiple,and a continuous flow injection analyzer was use to determine the cyanide content in the urine sample. Results This research showed a good line relationship for detecting cyanide in the concentration range of 0-0.200 mg/L,with a linear correlation coefficient of 0.999 6. The detection limit of the method was 0.005 4 mg/L. The spiked recovery experiment on urine samples at three different concentrations（low,medium,and high） were conducted,and the results showed that the recoveries ranged from 84.0% to 92.0%. The relative standard deviations of this method were 2.341% to 6.206%. Conclusion The continuous flow injection method for the detection of cyanide in urine has high sensitivity and good stability without complex pretreatment and derivation processes,and the whole process of online distillation is safe,which can be used for routine detection of cyanide in urine.

Key words: Continuous flow, Cyanide, Urine, Direct dilution