A New Method of Evaluation for an Agricultural Geological Survey Sample of 52 Quality Graded Projects

Soil geochemical sample analysis quality control is currently used to combine intra- and inter- laboratory quality control. The accuracy, precision and virtual figures play key roles in geochemical drawing mapping quality with a good application effect. However, the deficiency is a lack of a unified analysis method and the evaluation parameters of the quality level. The analysis coefficient is the comprehensive proxy to evaluate analysis results for accuracy and precision, which is suitable for the laboratory internal quality control and for interlaboratory quality control. This assessment method is simple to understand with the direct-viewing quantification indexes. Since there are few applications in the geology and mining laboratory, it has a good promotion application value. The analysis coefficient method was first applied to evaluate the analysis quality level of agricultural geological survey samples in Henan Province consisting of 4 daily monitoring soil standard materials in 52 projects. The allowable limit of the analysis coefficient was achieved based on the related indexes of multi-target regional geochemical survey specifications (1:250000). The division of the level of quality evaluation was established with this practical application. 4 soil standard materials with a total of 208 analysis projects were verified by this method, in which 138 items reached the outstanding level, 58 projects were good, 12 projects qualified, and the overall quality of the analysis was good. For the poor quality of Se, Cr, I, Br, Th, C, Pb and Cd projects, further work needs to be investigated further to improve the analysis accuracy and precision.