石墨炉原子吸收光谱法测定热封型茶叶滤纸中铅含量的不确定度评定

目的 评定石墨炉原子吸收光谱法测定热封型茶叶滤纸中的铅含量的不确定度。方法 采用GB31604.34-2016测定热封型茶叶滤纸中的铅含量。计算工作曲线、标准溶液、样品重复测定、仪器、吸光值量化误差、消解回收率、样品称量过程引入的不确定度,建立数学模型,计算合成不确定度。结果 石墨炉原子吸收光谱法测定热封型茶叶滤纸中铅的不确定度为0.10mg/kg。结论 影响检测结果的不确定度主要来源为校准曲线与消化回收率。

Uncertainty evaluation of determination of lead content in heat-sealed tea filter paper by graphite furnace atomic absorption spectrometry

Objective To evaluate the uncertainty in determination of lead content in heat-sealed tea filter paper by graphite furnace atomic absorption spectrometry. Methods The lead content in the heat-sealed tea filter paper was measured by GB 31604.34-2016. Uncertainties introduced by the working curve, standard solution, sample repeat measurement, instrument, absorbance quantification error, digestion recovery rate and sample weighing process were calculated, and a mathematical model was established to calculate the synthetic uncertainty. Results The uncertainty of determination of lead in heat-sealed tea filter paper by graphite furnace atomic absorption spectrometry was 0.10 mg/kg. Conclusion The main sources of uncertainty affecting the test results are the calibration curve and the digestion recovery rate.