混合磷酸盐pH溶液标准物质的研制

Development of Certified Reference Material for Mixed Phosphate pH Solution

通过遴选标准物质原材料,优化特性量值测量方法,采用溯源至美国国家标准与技术研究院(NIST)研制的标准物质的定值方法,系统介绍了混合磷酸盐pH溶液标准物质的研究工作。同时考察了标准物质的均匀性和稳定性,分析了样品的均匀性、测量的分散性及其他因素对不确定度的贡献,综合评定了整个研制体系的不确定度。稳定性考察结果表明,混合磷酸盐pH溶液标准物质在6个月内量值可靠稳定。其pH为7.41(25℃),pH的扩展不确定度为0.03 pH。该系列标准物质性能良好,已成功申请国家二级标准物质,编号为GBW(E) 130522,可满足食品、药品、日化、环境保护及化工产品研究和检测的需要,有望用于相关仪器(pH计)的校准、分析方法评价,为统一相关量值发挥应有的作用。

The research work of the certified reference material of mixed phosphate pH solution was systematically introduced by selecting the raw material,optimizing the measurement method of characteristic quantity value,and adopting the determination method of certified reference material traceable to the reference material from American National Institute of Standards and Technology ( NIST).The uniformity and stability of the certified reference material were investigated, the uniformity of the sample, the dispersion of the measurement and the contribution of other factors to the uncertainty were analyzed,and the uncertainty of the whole system was comprehensively evaluated.The results show that the certified reference material of the mixed phosphate pH solution was reliable and stable in 6 months.The pH value is 7. 41 at 25 ℃ with the expanded uncertainty of 0. 03 pH.The solution reference materials have been successfully identified as the national grade Ⅱ certified reference materials,which is numbered GBW( E) 130522, and can meet the needs of food,pharmaceutical,daily chemical, environmental protection and chemical product research and testing.It is also expected to be used in the calibration of instruments( pH meter) and method evaluation in food and cosmetic analysis.