测量系统分析在大米镉、铅元素检测中的应用研究

Application and Research of Measurement System Analysis for Detection of Cadmium and Lead in Rice

为提高大米中镉、铅元素检测数据的可靠性,根据GB 5009.12—2017《食品中铅的测定》、GB 5009.15—2014《食品中镉的测定》对大米中镉、铅元素含量进行检测,并以原子吸收分光光度计为测量设备的测量系统进行各类误差分析.结果表明,两种元素稳定性分析中Xbar控制图均存在超出上下控制界限的点,稳定性不满足要求.偏倚和线性P值均大于0.05,不存在显著的偏倚和线性误差.量具研究变异占比(Reproducibility&Repeatability,R&R)分别为54.03%和36.38%,均大于30%,测量误差超出可接受范围.通过人、机、料、法、环、测等多方面故障排查后稳定性达到统计受控状态,R&R分别降至9.66%和8.95%,均小于10%,测量系统可接受.利用测量系统分析方法从多方面降低各类测量误差,能够有效保障大米中镉、铅元素含量检测数据的可靠性.

In order to improve the reliability of detection data of cadmium and lead elements in rice,the content of cadmium and lead in rice were detected according to GB 5009.12—2017"Determination of Lead in Food"and GB 5009.15—2014"Determination of Cadmium in Food",and the various error analysis were carried out for the measuring system analysis(MSA)with the atomic absorption spectrophotometer as measuring equipment.The results showed that the Xbar control charts in the stability analysis of two elements have points beyond the upper and lower control limits,and the stability did not meet the requirements.The bias and linear P values were greater than 0.05,which meant that there were no significant bias and linear error.The results of Reproducibility&Repeatability(R&R)were 54.03%and 36.38%,respectively,both greater than 30%,and the measurement errors were beyond the acceptable range.The stability reached the statistical controlled state after the fault investigation of human,machine,material,method,environment,measurement and other aspects,and the R&R were reduced to 9.66%and 8.95%,respectively,both less than 10%,the measurement system was acceptable.The use of MSA method to reduce various types of measurement errors from many aspects,can effectively guarantee the reliability of the detection data of cadmium and lead contents in rice.