质量控制图在原子吸收光谱锰测定中的应用

采用原子吸收光谱仪测定锰质控样的浓度,收集20组数据,通过EXCEL函数功能计算均值(中心限)、标准偏差、上下控制限、上下警戒限、上下辅助限;用EXCEL图表功能绘制控制图,以测定日期为横坐标,锰浓度为纵坐标,中心线、控制线、警戒线、辅助线和测定数据线共同组成了完整的质量控制图。结果表明,锰浓度控制图的控制限为1.629～1.786 mg/L;警戒限为1.655～1.760 mg/L。当测定值未超出警戒限时,说明测量系统质量良好;当测定值超出警戒限但未超出控制限时,说明测量系统有失控的倾向;当测定值超过控制限时,说明测量系统失控,需要查明原因,采取纠正措施,确保测量系统持续受控。通过质量控制图可以考察测量系统的质量状况和变化趋势,判断检测过程是否受控,确定检测结果是否符合要求,它是实验室质量管理中一种有效的控制手段。

Application of Quality Control Chart in Mn Content Measurement by Flame Atomic Absorption Spectrometry

Mn content was detected by FAAS, 20 groups of detection data were collected, and general average （the central limit）, standard deviation, upper and low control limit, upper and low warning limit, and upper and low auxiliary limit were calculated by EXCEL function, then the detection date used as x-coordinate, Mn content used as y-coordinate, labeling the detected data, CL, UCL, LCL, UWL, LWL, UAL and LAL in the coordinate, seven parallel line finalty made integrated quality control chart. The control limit of Mn content was 1.629 - 1.786 mg/L and the warning limit was 1.655 - 1.760 mg/L. When the detected data was within the warning limit, the detecting system was well controlled. When the detected data exceeded the warning limit but was within the control limit, the detecting system was still under control but the deviation was concemed. When the detected data exceeded the control limit, the detecting system lost control and the corrective measures should be adopted to en- sure normal operation of the detecting system. The quality control chart was one of the useful QC approaches to settle the problems such as monitoring the status and the change trend of the detecting system, judging whether the detecting system was under control or not, and determining whether the detecting data were in accord with the requirements or not.