摘要
介绍化学需氧量(COD)在线自动监测仪示值误差的检定方法及注意事项。选取基准试剂邻苯二甲酸氢钾,依次配制零点溶液和质量浓度分别为50,150,500 mg/L的COD标准物质溶液,用于检定COD maxⅡ型在线监测仪的示值误差。直接配制溶液为100 mg/L的COD标准溶液,与相同浓度的标准物质溶液GBW(E)082219进行比较,结果符合检定规程JJG 1012–2006的要求。检定结果表明:以重铬酸钾为氧化剂时,邻苯二甲酸氢钾的COD氧化值呈线性关系,可直接配制100 mg/L的COD标准溶液;检定COD maxⅡ型在线监测仪,每次需要的标准溶液体积为100 m L,综合考虑,进行示值误差检定时,每种浓度至少配制500 m L。作为还原性标准物质用于检定仪器示值误差,邻苯二甲酸氢钾可能无法准确反映水体中有机物的真实还原情况,具有一定的局限性。
The method and attentions for verifation of on-line automatic determinator of chemical oxygen demand(COD)were introduced.Potassium hydrogen phthalate was selected to prepared zero solution and standard solution.Some standard solutions with50,150and500mg/L mass concentrations were used to calibrate indication error of monitoring instruments on-line of COD maxⅡtype.Compared with standard material solution GBW(E)082219,the result of laboratory prepared standard solution(100mg/L)conformed to the requirements of the regulations JJG1012–2006.It indicated that by the verification results the oxidation value of potassium hydrogen phthalate had a linear relationship and it could be used to prepare100mg/L standard solution directly;100mL volume should be needed each time and500mL should be prepared each level for the indication error verification.As a reducing standard material to verify the indication error of COD on-line automatic determinator,potassium hydrogen phthalate showed limitations for not precisely reflecting the reduction degree of organic compounds in water.
作者
朱全心
纪祥娟
孙文
杨新光
Zhu Quanxin;Ji Xiangjuan;Sun Wen;Yang Xinguang(Jining Institute of Metrology and Testing, Jining 272101, China;Lunan Institute of Coal and Chemical Industry Research, Jining 272000, China)
出处
《化学分析计量》
CAS
2017年第2期98-101,共4页
Chemical Analysis And Meterage
关键词
化学需氧量
在线自动检测仪
检定
示值误差
chemical oxygen demand
on-line automatic determinator
verification
indication error
