含硫酸脲复合肥料中氨挥发氮占总氮的百分率测定方法研究

Study on Determination Method of the Percentage of Ammonia Volatile Nitrogen in Total Nitrogen in Compound Fertilizers Containing Urea Sulfate

氨挥发氮占总氮的百分率是表征含硫酸脲复合肥料中氮素缓释性能的特征指标。试验分别采用尿素酶水解容量法和尿素酶水解分光光度法测定氨挥发氮占总氮的百分率,并进行了实验室内和实验室间测定值的对比分析。结果表明:实验室内两种方法测定值的相对偏差为0.08%~6.55%,3个实验室间所得测定值的相对标准偏差为3.9%~15.0%,两种方法均可用于氨挥发氮占总氮的百分率测定;尿素酶水解分光光度法的精密度高于尿素酶水解容量法的。

The percentage of ammonia volatile nitrogen in total nitrogen is a characteristic index that characterizes the slow-release performance of nitrogen in compound fertilizers containing urea sulfate.The test uses the urease hydrolysis volumetric method and the urease hydrolysis spectrophotometric method to determine the percentage of ammonia volatile nitrogen in total nitrogen,and a comparative analysis of the measured values in the laboratory and between the laboratories is carried out.The results show that the relative deviation of the measured values of the two methods in the laboratory is 0.08%to 6.55%,and the relative standard deviation of the measured values between three laboratories is 3.9%to 15.0%.Both methods can be used to determine the percentage of ammonia volatile nitrogen in total nitrogen;the precision of the urease hydrolysis spectrophotometric method is higher than that of the urease hydrolysis volumetric method.