双氰胺纯度标准物质的研制

Development of a certified reference material of dicyanodiamide

中文关键词:  双氰胺  标准物质  质量平衡法  差示扫描量热法  不确定度评定

英文关键词:dicyanodiamide  certified reference material  mass balance  differential scanning calorimetry  uncertainty evaluation

中文摘要:

      目的 建立双氰胺的纯度定值方法来研制双氰胺纯度标准物质(certified reference material, CRM), 并考察其均匀性、稳定性和不确定度。方法 采用基于高效液相色谱(high performance liquid chromatography, HPLC)的质量平衡法和差示扫描量热法(differential scanning calorimetry, DSC)2种方法对双氰胺的纯度进行定值。水分、无机杂质和挥发性溶剂分别采用卡尔费休滴定法(Karl Fischer, KF)、电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry, ICP-MS)和顶空气相色谱-质谱法(headspace gas chromatography mass spectrometry, HSGC-MS)测量。根据《标准物质定值的通用原则及统计学原理》(JJF 1343-2012)的要求, 采用高效液相色谱法进行均匀性和稳定性的检验。不确定度评定综合考虑均匀性、稳定性、定值过程引入的不确定度。结果 均匀性和稳定性检测结果表明: 均匀性良好, 在规定的保存条件下可以稳定保存36个月以上。研制的双氰胺标准物质的纯度为99.8%, 扩展不确定度0.3%(k=2)。结论 本研究研制双氰胺标准物质的量值具有溯源性和准确性。

英文摘要:

      Objective To develop a certified reference material (CRM) of dicyanodiamide by purity determination, andinvestigate its homogeneity, stabilityand uncertainty. Methods The purity of dicyanodiamide was obtained by mass balance method based on high performance liquid chromatography (HPLC) and differential scanning calorimetry (DSC) method. The content of water, inorganic impurities and volatile solvents were measured by Karl Fischer (KF) titration method, inductively coupled plasma mass spectrometry (ICP-MS) method and headspace gas chromatography mass spectrometry (HSGC-MS) method. Homogeneity and stability tests were carried on according to General and statistical principles for characterization of reference materials (JJF 1343-2012) by HPLC. Uncertainty was evaluated in consideration of homogeneity, stability and value assignment process. Results The results of uniformity and stability test showed that the uniformity was good, and it could be stored for more than 36 months under the prescribed storage conditions. The certified purity value of dicyanodiamide was 99.8% with an expanded uncertainty of 0.3% (k=2). Conclusion In this established method, the value of dicyandiamide in biological standard material is traceability and accuracy.