离子选择电极在水土流失养分监测中的应用

摘要

The soil erosion nutrient loss in runoff was usually analyzed in laboratory after collecting in field which is very complex. This paper presented a fast measuring method which was ion selective electrode( ISE ). To study this method, ammonium ISE and the traditional Nessler's reagent spectrophotometry were investigated by simulating rainfall in accuracy, anti-jamming ability and mechanism of migration. Results show that the maximum value measured of measuring range ISE is 1000mg/L and spectrophotometry was 2mg/L. When the process of ammonia nitrogen loss in runoff on the slope is fitted by power function model,the fitting coefficient of ISE and spectrophotometry is 0. 9537 and 0. 9305. At the 95% confidence level,two methods are no significant difference. Compared with spectrophotometry,the standard deviation ISE is smaller,so the value measured by ISE is more close to the standard value.%水土流失径流养分监测通常采用野外采集后进行实验室分析的方法，操作复杂。为验证离子选择电极这种可快速测量养分的方法在水土流失监测中的可靠性，以氨氮离子选择电极为例，与传统纳氏试剂分光光度法进行比较，在准确度、抗离子干扰及坡面径流迁移规律等方面进行实验。结果表明：电极法测定范围最大值为1000 mg/L，分光光度法测定范围最大值为2 mg/L；用幂函数模型模拟坡面径流氨氮迁移规律时，电极法测定值的拟合系数为0.9537，分光光度法的为0.9305。在95%的置信水平上，两方法结果并无显著性差异，而电极法的标准偏差小，其结果更接近标准值。