食品重金属快速检测仪测量大米中痕量镉的长期稳定性研究

Study on the long-term stability ofthe trace Cadmium in rice by fast heavy metal analyzers

通过对397台食品重金属检测仪测量大米中镉的长期稳定性测量数据进行统计,引入系统评价方法研究仪器在相应时段内的检验重复性、检验时段间的总精密度及总平均值的正确度。大米标准样品GBW(E)100348中镉的总平均值在认定值±5%区间内波动,统计发现,时段内相对标准偏差≤15%的仪器占98.5%,长期稳定性满足精密度要求的仪器占99.75%,检验时段内总精密度满足要求的仪器占97.5%,仪器长期测量数据的总平均值100%满足正确度统计要求。

Through analysis of the long-term stability of trace cadmium in rice by 397 heavy metals analyzers for food,the systematic evaluation method was introduced to study the testrepeatability,total precision in the corresponding period and the accuracy of total average value.Overall averages of Cd are fluctuated in the range of±5%around standard values.Statistics show thatCd RSD of 98.5%instruments were less than 15%,long-term stability of 99.75%instruments satisfied the requirement of precision,total precision of 97.5%instruments met the requirements in test period,100%of the total average value of the long-term measurement data of the instrument meets the statistical requirements of accuracy.