X-射线荧光光谱仪快速筛查大米中镉的含量

建立X-射线荧光法测定大米中镉含量的分析方法。方法 样品经粉碎后,压片,直接置于仪器上测定25 min。结果 仪器方法检出限和定量限分别为0.035和0.094 mg/kg；准确度标准偏差为0.015 5,t_d=0.30,重复性χ²=5.32,12 h内仪器稳定性χ²=11.07,随机两台仪器测定结果的标准偏差为0.021 3。结论 X-射线荧光光谱仪检出限和定量限能够满足大米中镉的检测的标准要求,仪器准确度、重复性和稳定性符合快速测定要求,X-射线荧光法为大米中镉的快速筛查提出了新方法,同时为基层粮库稻米收购,食品原料验收和监管提供了技术支撑。

Rapid screening of cadmium in rice by X-ray fluorescence spectrometer

A method of X-ray fluorescence spectrometer was established for rapid screening of cadmium in rice.MethodsThe rice was detected by X-ray fluorescence spectrometer after crushed.ResultsThe limit of detection and quantification of detection were 0.035 and 0.094 mg/kg, the standard deviation of accuracy was 0.015 5 and the value of t-test was 0.30. Chi-square value of repeatability was 5.32, and the chi-square value of stability was 11.07 within 12 h. The standard deviation was 0.021 3 between two instruments.ConclusionThe results indicated that the X-ray fluorescence spectrometer could meet the standard requirements of cadmium in rice. The accuracy, repeatability and stability of instrument could meet the requirement of rapid screening. A new rapid screening method for cadmium in ricewas developed. It provided technical support for purchasing grain in grassroots grain depot, acceptance check and supervision of food raw material.