作者：邢书才, 杨永, 岳亚萍, 张覃, 赵彦辉, 杨刚
作者单位：国家环境保护污染物计量和标准样品研究重点实验室, 环境保护部标准样品研究所, 北京 100029
关键词：碘量法;滴定分析;分析质量
摘要：
对滴定分析中影响分析质量的主要因素进行分析和论述。以滴定分析中最具代表性的碘量法为测定实例，采用现行国家标准分析方法对实际待测样品进行分析测定。根据实测数据，对滴定分析中影响质量的因素进行深入剖析，论述在样品滴定测定中，由于被测样品与碘标准溶液加入量比不恰当、平行测定中的不规范操作、滴定终点判断的不合理等问题，对滴定实验结果产生的影响。同时根据这些影响因素，分别从待测样品与标准溶液的加入量、样品平行测定的正确操作、滴定终点判断中指示剂的加入时机、滴定速度等方面提出相关建议。可为检测实验室滴定分析和相关分析方法的实施提供技术支持。
The study on the factors affecting analysis quality in iodometric titration
XING Shucai, YANG Yong, YUE Yaping, ZHANG Qin, ZHAO Yanhui, YANG Gang
State Environmental Protection Key Laboratory of Environmental Pollutant Metrology and Reference Materials Study, Institute for Environmental Reference Materials of Ministry of Environmental Protection, Beijing 100029, China
Abstract: The main factors affecting analysis quality were analyzed and discussed in the titration experiments. The most representative iodometric method in the titration analysis was taken as an example and the present national standard analytical method was used to analyze and measure the actual sample. The influencing factors of the analytical quality in the titration analysis were analyzed based on the actual measurement data. Moreover, this paper discussed the influence in detail on the titration experimental results in the sample titration caused by the inappropriate proportion of the sample and the iodine standard solution, the non-standard operation in the parallel determination and the unreasonable judgment of the titration end point. Meanwhile, relevant suggestions were given in the aspects of the amount of standard solution into the sample, the correct operation of the parallel sample, the timing adding the indicator in the titration end point and the titration rate according to these influencing factors. This study can provide technoloy support for the laboratary titration analysis and relative analysis method.
Keywords: iodometric method;titration analysis;analysis quality
2018, 44(9): 44-50 收稿日期: 2018-04-12;收到修改稿日期: 2018-05-08
基金项目: 国家标准化管理委员会国家标准制修订项目（S2012041）
作者简介: 邢书才(1958-),男,北京市人,教授级高级工程师,主要从事环境监测和国家标准的研究
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