高效液相色谱-电感耦合等离子体质谱法研究标准曲线质量浓度范围对虾油中无机砷测量不确定度评定的影响

Influence of mass concentration range of standard curve on uncertainty of determination of inorganic arsenic in krill oil by HPLC-ICP-MS

通过建立高效液相色谱-电感耦合等离子体质谱法测定虾油中无机砷含量,建立数学模型对测试过程系统产生的不确定度进行计算、评定。按GB 5009.11—2014《食品中总砷及无机砷的测定》测定虾油中无机砷含量,采用3种质量浓度范围的标准系列溶液测试相同样品的无机砷含量,研究标准曲线质量浓度范围对虾油中无机砷不确定度的影响。结果表明:3种标准系列溶液测得的相同样品的质量浓度和无机砷测试过程中系统产生的不确定度分别为(0.56±0.536)ng/mL、(0.56±0.115)ng/mL和(0.55±0.030)ng/mL,相对扩展不确定度分别为191.4%、41.1%和10.9%。研究表明,随着标准曲线质量浓度范围的扩大,不确定度随之增大,测定结果的准确性降低。

The determination of inorganic arsenic in krill oil was established by high performance liquid chromatography-inductively coupled plasma mass spectrometry.The mathematical model was established to calculate and evaluate the uncertainty of the test process system.The content of inorganic arsenic in krill oil was determined according to GB 5009.11—2014 Determination of total arsenic and inorganic arsenic in food.Inorganic arsenic content of the same sample was tested in the standard series of three concentration ranges,and the effect of the mass concentration of standard curve on the uncertainty of inorganic arsenic in krill oil was evaluated.The results showed that the mass concentration and uncertainty of the same sample measured under the three standard series were(0.56±0.536)ng/mL,(0.56±0.115)ng/mL and(0.55±0.030)ng/mL respectively,and the relative expansion certainty were 191.4%,41.1%and 10.9%,respectively.The research showed that as the mass concentration range of the standard curve increased,the uncertainty evaluation results increased,and the accuracy of the measurement results was lower.