高效液相色谱-电感耦合等离子体质谱法测定大米中无机砷的不确定度评定

Uncertainty evaluation for determination of inorganic arsenic in rice by high performance liquid chromatography-inductively coupled plasma mass spectrometry

中文关键词:  高效液相色谱-电感耦合等离子体质谱法  大米  无机砷  不确定度

英文关键词:high performance liquid chromatography-inductively coupled plasma mass spectrometer  rice  inorganic arsenic  uncertainty

中文摘要:

      目的 评定液相色谱-电感耦合等离子体质谱法测定大米中无机砷的不确定度。方法 采用高效液相色谱-电感耦合等离子体质谱法测定大米中无机砷含量, 并根据该分析过程的测量数学模型从测量重复性、样品称量、样品空白、提取液移取体积、标准溶液配制、提取液中i-As浓度和回收率等方面进行测量不确定度的计算。结果 大米粉样品中AsⅢ, AsⅤ, i-As的含量分别为0.045、0.154、0.199 mg/kg, 在95%的置信区间下, 其扩展不确定度为0.006、0.012、0.030 mg/kg, k=2。测量过程中的不确定度主要来源于测定的重复性、提取液中无机砷含量的计算、标准溶液的配制和方法的回收率。结论 所建立数学模型可对高效液相色谱-电感耦合等离子体质谱法测定固体样品中无机砷测量的不确定度进行合理的评定。

英文摘要:

      Objective To evaluate the uncertainty for determination of inorganic arsenic in rice by liquid chromatography-inductively coupled plasma mass spectrometry. Methods The content of inorganic arsenic in rice was determined by high performance liquid chromatography-inductively coupled plasma mass spectrometry. According to the mathematical model ofthe analysis process, the measurement uncertainty was calculatedfrom the measurement repeatability, sample weighing, sample blank, extraction volume, standard solution preparation, concentration of i-As in the extraction solution and recoveries. Results When the contents of AsⅢ, AsⅤ and i-Asin rice were 0.045, 0.154, 0.199 mg/kg, the extended uncertainties were 0.006, 0.012, 0.030 mg/kg(k=2) under the 95% confidence interval. The uncertainty in the measurement process mainly derivedfrom the repeatability of measurement, the calculation of inorganic arsenic content in extraction solution, the preparation of standard solution and the recoveries of the method. Conclusion The mathematical model can be used to evaluate the uncertainty for thedeterminationof inorganic arsenic measurement in solid samples by high performance liquid chromatography- inductively coupled plasma mass spectrometry.