Application of sampling and analytical quality control to determination of Mn in tea garden soils using chemical extraction

Errors of the analytical method were assessed by a traditional analytical quality control technique. Afterward, the sampling variance, the analytical variance, and the geochemical variance were estimated respectively in measurement of available Mn in soils by using a sampling and analytical quality control scheme (SAX) and robust analysis of variance (robust ANOVA). The results show that the precision of measurement was quite good for a clear description of geochemical variation between sample sites. The effect of Mn contamination seemed to be more sensitive in the chemical analysis procedure than that in the sampling procedure.