目的 评定气相色谱法测定塑料包装中3种抗氧化剂含量的不确定度，进一步提高塑料包装中抗氧化剂检测数据的准确性。方法 根据SN/T 3042—2011采用气相色谱法对塑料包装中3种抗氧化剂含量进行测定，经过分析不确定度的影响因素，根据相应的数学模型计算各主要影响因素的不确定度，给出塑料包装中3种抗氧化剂测定结果的扩展不确定度。结果 塑料包装中3种抗氧化剂的测量扩展不确定度:丁基羟基茴香醚(BHA)为(14.65±1.09)mg/kg、2,6-二丁基羟基甲苯(BHT)为(14.68±1.03)mg/kg、特丁基对苯二酚(TBHQ)为(14.44±0.65)mg/kg(P=95%，k=2)。结论 气相色谱法测定塑料包装中3种抗氧化剂含量的测量不确定度的主要影响因素为标准曲线拟合、配制标准工作液的量具以及仪器精密度。可通过使用精度更高的量具及仪器、选择合适的标准工作溶液浓度点、提高人员实操水平等措施减少不确定度，进一步提高检测数据的准确度。

The work aims to evaluate the uncertainty in determining the content of three antioxidants in plastic packaging materials by gas chromatography, and further improve the accuracy of the antioxidant detection data in plastic packaging materials. According to SN/T 3042—2011, the content of 3 antioxidants in plastic packaging materials was determined by gas chromatography. After analysis of factors affecting the uncertainty, the uncertainty of each main factor was calculated according to the corresponding mathematical model and the expanded uncertainty of the measurement results of 3 antioxidants in plastic packaging materials was obtained. The expanded uncertainty of measurement of three antioxidants in plastic packaging materials was BHA:(14.65±1.09)mg/kg, BHT:(14.68±1.03)mg/kg and TBHQ:(14.44±0.65)mg/kg (P=95%, k=2). The main factors affecting the determination uncertainty of the content of three antioxidants in plastic packaging materials by gas chromatography are:standard curve fitting, measuring tool for preparing standard working fluid and instrument precision. The uncertainty can be reduced by more accurate measuring tools and instruments, suitable concentration points of standard working fluid, and improved practical level of personnel, so as to further improve the accuracy of detection data.