咖啡花中高氯酸盐含量超高效液相色谱-串联质谱测定法的不确定度评价

Evaluation of uncertainty in the determination of perchlorate in the flower of Coffea by ultra-performance liquid chromatography-tandem mass spectrometry

目的采用超高效液相色谱-串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry,UPLCMS/MS)测定咖啡花样品中高氯酸盐含量,并对检测过程进行不确定度评价。方法依据JJF 1059.1—2012《测量不确定度评定与表示》,分析并计算检测过程中的各项不确定度分量,最后合成得到超高效液相色谱-串联质谱法测定咖啡花中高氯酸盐含量的扩展不确定度。结果在本实验中,咖啡花样品中高氯酸盐的含量为(0.1313±0.0122)mg/kg,k=2,相对标准偏差为2.39%。结论超高效液相色谱-串联质谱法测定咖啡花样品中高氯酸盐含量过程中不确定度的主要来源为配制标准系列过程中吸取同位素内标的移液器、配制标准系列过程中使用的玻璃量器及移液器和标准系列测定及拟合过程。

Objective To determine the content of perchlorate in the flower of Coffea samples by ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS),and to evaluate the uncertainty of the testing process.Methods To analyze and calculate various uncertainty components in the detection process according to JJF 1059.1-2012"the Evaluation and Expression of Uncertainty in Measurement",and finally synthesizing the extended uncertainty for the determination of perchlorate content in the flower of Coffea samples by UPLC-MS/MS.Results In this experiment,the content of perchlorate in the flower of Coffea samples was(0.1313±0.0122)mg/kg,k=2,and the relative standard deviation was 2.39%.Conclusion In the determination of perchlorate content in the flower of Coffea by UPLC-MS/MS,the uncertainty are mainly derived from the pipette absorbing isotope internal standard in the process of preparing standard series,the glass gauge and the pipette during the dilution process of standard materials,the determination and fitting of the standard curve.