气相色谱法测定藻油中DHA含量的 不确定度的评定

Assessment of content uncertainty of DHA in algal oil by gas chromatography

中文关键词:  气相色谱法  DHA  不确定度

英文关键词:gas chromatography  DHA  uncertainty

中文摘要:

      目的 对采用气相色谱法测定藻油中DHA含量的不确定度进行分析, 找出影响不确定度的因素, 为评价其测定方法和检测结果的可靠性提供依据。方法 根据JJF1059.1-2012《测量不确定度的评定与表示》的规定, 对测定过程中重复测量、样品溶液的配制、标准溶液的配制、检测仪器等引入的不确定度分量进行评定。结果 测定结果合成不确定度为0.9%, 扩展不确定度为1.8%。藻油中DHA含量测定结果为(28.5±0.5) g/100 g (k=2), 即有95%可能性为28.0~29.0 g/100 g。结论 标准溶液和样品溶液的配制是影响不确定度的主要因素, 使用校准级别高的容量瓶以及精密度高的天平仪器, 可有效减少此类测量的不确定度, 说明建立的不确定度评定方法可用于气相色谱方法测定藻油中DHA含量结果的判断。

英文摘要:

      Objective To analyze the content uncertainty of DHA in algal oil by gas chromatography (GC), and find out the influence factors of the uncertainty, so as to provide the basis for the evaluation of the measurement method and the reliability of the test results. Methods The uncertainty components were as-sessed through the determination of the process of repeated measurement, the preparation of sample solution, the preparation of standard solutions and testing instruments according to regulation of JJF1059.1-2012 “Evaluation and Expression of Uncertainty in Measurement”. Results The synthetic uncertainty was 0.9%, and the expanded uncertainty was 1.8%. The content of DHA in algal oil was (28.5+1.8) g/100 g (k=2), and it had 95% probability of 28.0~29.0 g/100 g. Conclusion Preparation of standard solutions and sample solution are the main factors of uncertainty. The high-level calibration flask and high precision balance instrument should be used, which can effectively reduce the measurement uncertainty. The uncertainty assessment method can be used for the judgment of determining DHA content in algal oil by GC.