目的 提高动态反应池模式电感耦合等离子体质谱法(DRC-ICP-MS)测定卷烟纸中钾含量的精密度，确保检测结果的准确性，识别和掌握影响测定的关键因素并实施有效监控和改进。方法 依据JJF 1059.1—2012《测量不确定度评定与表示》，采用因果图对不确定度的主要来源进行分析，通过数学模型科学评定各不确定度分量，提出扩展不确定度。结果 各相对标准不确定度分量值介于0.0067～0.0402之间。根据分量所占权重大小，不确定度对测定结果影响程度依次为标准溶液配制、样品水分含量、样品重复测量、工作曲线拟合、样品制备。当卷烟纸中钾含量为13.337 mg/g时，其扩展不确定度为1.218 mg/g（k=2，P=95%）。结论 优化标准溶液配制环节能适当降低不确定度，同时检测时要密切关注仪器状态，仪器的稳定性会同步影响不确定度的最终结果。

The work aims to improve the precision and accuracy of the determination of potassium in cigarette paper by inductively coupled plasma mass spectrometry with dynamic reaction cell (DRC-ICP-MS), identify and master the key factors, and implement effective monitoring and improvement. The main sources of uncertainty were analyzed by the cause-and-effect diagram, the components of uncertainty were evaluated scientifically by the mathematical model, and the expanded uncertainty was proposed according to JJF 1059.1—2012 “Evaluation and Expression of Uncertainty in Measurement”. The results demonstrated that the components of uncertainty were in the range of 0.0067 to 0.0402. The influences on determination results were standard solution preparation, moisture content of sample, sample repeated measurement, calibration curve fitting and sample preparation on the basis of the weights of various components of uncertainty. When the potassium in cigarette paper sample was 13.337 mg/g, the expanded uncertainty was 1.218 mg/g (k=2, P=95%). In conclusion, the uncertainty can be reduced by optimizing the standard solution preparation. Furthermore, the stability of the instrument can influence the uncertainty simultaneously. Therefore attention should be paid to the instrument status closely.