微波消解火焰原子吸收光谱法测定茶叶中铜含量不确定度

摘要

The uncertainty of copper contents in tea was reasonably evaluated by microwave-assisted digestion with flame atomic absorption spectrophotometry (AAS). The uncertainty mainly derived from repeating experiments of samples, the copper concentration of tea solution, and weighing & volume of tea sample,respectively.In this study, the combined standard uncertainty of the measurement results was 0.38 μg/g, the final result of copper content in the standard material GBW 08505 was 16.9±0.76 μg/g ( k=2, P=95 % ). The result showed that the method of microwave digestion-AAS is suitable and could be regarded as a reference of the safe, green and high efficient method for determining copper content in tea samples.%应用微波消解-火焰原子吸收光谱法测定标准样品茶叶(GBW 08505)中铜含量,并从测量重复性、茶叶溶液铜的浓度和试样称量及定容等方面对上述方法的不确定度进行了评估和计算.对于标准茶叶样品,上述方法的标准合成不确定度为0.38μg/g,Cu的含量为16.9±0.76μg/g(k=2,P=95%).结果表明,该方法能够有效地应用于茶叶样品中铜含量的精密检测,并且可以作为参考运用于其它类似食品的检测工作中.