丙酮中除虫脲溶液标准物质研制

采用重量-容量法制备丙酮中除虫脲溶液标准物质。准确称量国家二级标准物质除虫脲溶解到色谱纯丙酮中,通过A级容量瓶定容至500 mL,摇匀后分装到2 mL安瓿瓶内共460瓶,每瓶为1 mL,保持低温迅速封口,配制过程中室温保持在(20±2)℃。采用液相色谱法进行均匀性、稳定性检验和定值结果验证。从样品中随机抽取16瓶进行均匀性检验,经F检验表明,在95%的置信区间范围内该标准物质均匀性良好;采用t检验对标准物质稳定性进行检验,标准物质在12月内稳定性良好。对该标准物质的不确定度进行了评定,研制的丙酮中除虫脲溶液标准物质定值结果为100μg/mL,相对扩展不确定度为2%(k=2)。结果表明,该标准物质均匀性与稳定性良好,量值准确,可用于日常分析检测中的方法评价和仪器校准。

Preparation for solution standard substance of diflubenzuron in acetone

The standard substance for diflubenzuron in acetone was prepared by weight-volume method.Certified secondary national standard substance was quantitatively dissolved in chromatographic pure acetone,the ambient temperature was(20±2)℃.The solution was fixed to 500 mL with a grade A volumetric bottle,then the solution was shaken well and subpackaged into 460 of 2 mL ampoule bottles,each ampoules was fixed 1 mL,sealed quickly at low temperature.The uniformity,stability and values were tested by liquid chromatography.The F-test showed that the uniformity was good within the 95%confidence interval by selected 16 bottles from the samples randomly.The stability was good within 12 months by t-test.The uncertainty was assessed and the standard value was 100μg/mL with the relative exband uncertainty U=2%(k=2).The results showed that the uniformity and stability of diflubenzuron in acetone solution reference material were satisfied,the values were accurate.It can be used for method evaluation and instrument calibration in daily analysis.