Trial Application of 6σ Quality Management Method to Evaluate the Quality Level of Detection Items of Multiple-target Geochemical Samples

It is the first attempt to apply six sigma (6σ) quality managment method to evaluate the X-ray fluorescence spectrometry detection method for four multi-objective reference substance of soil, which include 27 targets such as Cl, S, total carbon, N, Na₂O, MgO, Al₂O₃, SiO₂, P, K₂O, CaO, Ba, Ti, V, Cr, Mn, TFe₂O₃, Zn, Ga, Br, Pb, Th, Rb, Sr, Y, Zr, Nb. The research result shows that the precision and accuracy of multi-objective analysis with multiple target samples have been improved along with high precision and automatic equipment applications. Some of the items have reached 6σ quality level. But there are a few targets such as N, Total carbon and Cr were lower than 3σ quality level and their precision and accuracy are required to be improved, therefore, recommend to change detection method. Evaluations of geological analysis with 6σ quality management methods are consistent with traditional quality control methods. The evaluation method is simple, quantitative and intuitive with certain practical value.