流动注射分光光度法测定游泳池水中尿素

Determination of urea in swimming poor water by flow injection-spectrophotometry analysis

目的建立一种快速准确测定游泳池水中尿素的流动注射分光光度法。方法尿素在强酸环境下与二乙酰一肟及硫代氨基脲加热可生成红色的二嗪衍生物,采用QC8500流动注射分析仪,通过在线加热及在线冷凝,于530 nm处进行比色测定。结果在0.040 mg/L^10.000 mg/L时,尿素的吸收峰面积(y)与其浓度(x)成线性关系,标准曲线回归方程为y=4.83x+1.06,相关系数r=0.999 9,检出限为0.005 6 mg/L,相对标准偏差(RSD)<4.5%。对普通淡水浴池水样和海水浴场水样进行加标回收实验,回收率为98.0%~103.3%。本方法的测定结果与国家标准方法的检测结果差异无统计学意义。样品分析速度为30样/h。结论本方法线性范围宽,简便快速,适合游泳池水中尿素的批量测定。

Objective To establish a method for the determination of urea in swimming poor water by flow injection-spectrophotometry analysis.Methods Urea,diacethyl monoxime and thiosemicarbazide can generate oxadiazine in the acid environment under heating.Based on this principle,the flow injection system QC8500 which includes on-line heating and on-line condensation can detect trace urea in swimming poor water at 530 nm.Results Under the optimized condition,the absorption peak area of urea（y） was linear with the concentration of urea（x） in the range of 0.040 mg/L-10.000 mg/L.The linear regression equation was y = 4.83 x ＋ 1.06,with correlation coefficient（r） of 0.999 9,with the detection limit of 0.005 6 mg/L.The detection limits of urea was 0.005 6 mg/L.The recoveries for different urea concentrations varied from 98.0% to 103.3%,and the RSD was less than 4.5%.There was no significant difference between the results of this method and the national standard method.A sampling frequency of 30 samples per hour was achieved with this method.Conclusion This simple method exhibits wide linearity and is suitable for the determination of urea in swimming poor water.