电位法测定土壤pH值不确定度评定  

Uncertainty Evaluation in Determination of pH Value in Soil by Potentiometric

作　　者：刘小萍 胡造时 闭潇予 Liu Xiaoping;Hu Zaoshi;Bi Xiaoyu(Guangxi Zhuang Autonomous Region Environmental Monitoring Centre,Nanning 530028,China)

机构地区：[1]广西壮族自治区生态环境监测中心,广西南宁530028

出　　处：《广东化工》2024年第14期134-136,共3页Guangdong Chemical Industry

摘　　要：土壤pH值是土壤分析中的一项重要指标,许多土壤分析项目需要根据土壤的pH值进行选择相应的分析方法,检测结果也都与土壤pH值有关联,是审核其他项目结果的重要依据。本文根据测量不确定度评定理论,结合电位法对土壤pH值测量不确定度进行全面分析。从测定的重复性、样品称重、浸提前处理、仪器示值误差、仪器校准5个方面归纳不确定度来源,对各不确定度分量详细评定,并由各不确定度分量合成得到土壤pH值测定的相对标准不确定度及扩展不确定度,得出土壤pH值的测量不确定度为8.24±0.03。在分析过程中,对比各个不确定度分量对土壤pH值测定不确定度的贡献大小,其中pH标准缓冲溶液校准引入的不确定度分量最大。Soil pH value is an important indicator in soil analysis,and many soil analysis projects require the selection of corresponding analysis methods based on the soil pH value.The detection results are also related to the soil pH value,which is an important basis for reviewing the results of other projects.This article comprehensively analyzes the uncertainty of soil pH measurement based on the theory of measurement uncertainty evaluation and the potential method.The sources of uncertainty were summarized from five aspects:repeatability of measurement,sample weighing,pre soaking treatment,instrument indication error,and instrument calibration.Each uncertainty component is evaluated in detail,and the relative standard uncertainty and expanded uncertainty of soil pH measurement are synthesized from each uncertainty component.The measurement uncertainty of soil pH was determined to be 8.24±0.03.In the analysis process,the contribution of various uncertainty components to the uncertainty of soil pH measurement is compared,among which the uncertainty component introduced by the calibration of pH standard buffer solution is the largest.

关 键 词：土壤 PH值 电位法 测量不确定度 评定 

分 类 号：O657.1[理学—分析化学]