高效液相色谱法测定N-甲基-对硝基苯胺含量的不确定度评定

Uncertainty evaluation of determination of N-methyl-p-nitroaniline by HPLC

建立了高效液相色谱法测定N-甲基-对硝基苯胺含量不确定度评定的数学模型,全面考虑样品在测量过程中的不确定度来源。结果表明,称样量较小时,样品、标样在称量过程中引入的不确定度较大;稀释定容过程中,使用量程较大的移液管和容量较大的容量瓶会降低稀释定容过程中引入的不确定度;提高分析工作者的业务技能也可以降低样品测定的不确定度。当取样量为0.0141g时,测定样品中含有MNA的质量为(7.0±0.5)mg, k=2。

The mathematical model of uncertainty evaluation is established. The results show that when the sample weight is small, the uncertainty introduced in the weighing process of the sample and standard sample is large;the uncertainty introduced in the process of dilution and constant volume can be reduced by using the pipette with large range and volumetric flask with large capacity;the uncertainty of sample determination can also be reduced by improving the professional skills of analysts. When the sample mass is 0.0141 g, the mass of MNA in the sample is(7.0±0.5)mg, k=2.