石墨炉原子吸收法测定水产品中镉的不确定度

Uncertainty Evaluation for Determination of Cadmium in Aquatic Products by GFAAS

采用石墨炉原子吸收光谱法,测定大虾成分分析标准物质(GBW 10050)中镉含量,分析其不确定度来源,建立不确定度评定的数学模型,并计算不确定度分量。结果表明,石墨炉原子吸收光谱法的不确定度主要来源于标准曲线的拟合和标准曲线溶液配制。该方法测定质控样品GBW 10050镉含量0.0379 mg/kg时,扩展不确定度为0.0028 mg/kg,k=2。试验结果为提升水产品镉含量测定方法的可信度和准确性提供依据。

Graphite furnace atomic absorption spectrometry(GFAAS)was used to determine the concentration of cadmium in Prawn Composition Analysis CRM(GBW 10050).The main components of uncertainty in GFAAS were analyzed.A model of uncertainty evaluation was established,and each uncertainty component was quantified.The results applied that variability of calibration curve and standard solution preparation were the main source of uncertainty.The expanded uncertainty was expressed as 0.0028 mg/kg,k=2 if cadmium of GBW 10050 was 0.0379 mg/kg.