苯酚纯度标准物质的定值及不确定度分析

Purity Determination and Uncertainty Evaluation of Phenol Reference Material

建立了苯酚纯度标准物质的定值和不确定度评定方法。通过气相色谱-质谱法和傅里叶变换红外光谱法进行定性分析。为了提高定值准确度,同时采用了质量平衡法(MB)和差示扫描量热法(DSC)进行定值分析,其中质量平衡法包括高效液相色谱面积归一化法(HPLC-AN)、气相色谱面积归一化法(GC-AN)、水分、溶剂残留和灰分分析。运用HPLC法进行了均匀性检验和稳定性考察。分别建立MB和DSC方法的测量模型,根据不确定度传播率推导和计算各个不确定度分量和合成标准不确定度,定值结果为99.42%,相对扩展不确定度为0.20%(k=2)。该标准物质对于化妆品等基体中苯酚的量值传递和量值溯源具有重要意义。

The approach for purity determination and uncertainty evaluation of phenol reference material was established.The qualitative analysis was performed via the gas chromatographic mass spectrometry（GC-MS） and fourier transform infra redspectroscopy（FT-IR）,while the quantitative analysis was carried out by means of differential scanning calorimetry（DSC） and balance method（MB） simultaneously,by which the accuracy of purity result was supposed to be enhanced.The MB method was based on area normalization methods of both high performance liquid chromatography（HPLC-AN） and gas chromatography（GC-AN） as well as impurity assessment.The uniformity and stability of phenol reference material was investigated by HPLC.The determination of uncertainty components and the combined standard uncertainty were accomplished by establishment of the measurement models involving both MB method and DSC,followed by derivation and calculation of formulas on basis of uncertainty spreading rate.The purity determined in this way was 99. 42% with the relative standard uncertainty of 0. 20%（k = 2）.The reference material was of great significance in view of quantity transfer and value traceability.