ABSTRACT
Objective To develop a stable and quick method to determine the urea in swimming pool water.Methods On the conditions of strong acid and calefaction,urea can react on antipyrine and diacetyl monoxime and become yellow which can be determined by colorimetric analysis in 450 nm with the ALLIANCE FUTURA continuous flow injection auto analysis system.Results Determined by this method,the linear range was 0.5-4.0 mg/L,the regression equation was y=0.077 5x+0.021 9,the correlative coefficient r=0.999,the detection limit was 0.07 mg/L.With residual chlorine of 0.3 and 3.0 mg/L,the recovery rates were 98.8%-104.0% and did not disturb the determination.The results determined by the present method were the same as those by the method in GB/T 18204.29-2000(Wilcoxon Signed Ranks Test:Z=0.051,P=0.959).Conclusion Determination of the urea in swimming pool water with continuous flow injection auto analysis,the sensitivity,accuracy and limit of determination can meet to the requirement,moreover,the analysis speed is faster,less reagent will be needed,the present method can be generalized in the laboratory that has the conditions.