电位法测定土壤pH的精密度与准确度

Precision and Accuracy of Soil pH Determination by Potentiometry

采用电位法对标准HJ 962—2018进行了准确度与精密度的验证。按照环境监测分析方法标准制订技术导则HJ 168—2020中规定的要求,分别对酸性、中性、碱性3种pH值的有证土壤标准样品以及实际土壤样品进行6次平行测定,测定结果显示相对标准偏差在0.1%~0.3%,相对误差在1.3%~2.1%。因而不同酸碱性土壤样品pH值的测定准确度与精密度均满足要求。

The accuracy and precision of standard HJ 962-2018 were verified by potentiometric method.According to the requirements stipulated in the Technical Guidelines for Environmental Monitoring and Analysis Method Standard Formulation HJ 168-2020,six parallel measurements were carried out on the certified soil standard samples of acidic,neutral and alkaline pH values and the actual soil samples respectively.The results showed that the relative standard deviation was between 0.1%and 0.3%,and the relative error was between 1.3%and 2.1%.Therefore,the determination accuracy and precision of pH values of different acid-base soil samples meet the requirements.