Detection Limit (LOD) and Limit of Quantification (LOQ) Using Microscopical Methods in Asbestos Analysis
SourceOptical methods (light or electron microscopy) are, in most cases, the basis for measuring the asbestos concentration either in air or in materials. The individual methods are described in a variety of guidelines or standards. The definition of terms like detection limit and analytical sensitivity have led to numerous discussions, driven by the fact that in some cases concentrations that are real and not a misinterpretation are reported as below the stated detection limit. In this paper, different approaches for a detection limit (LOD) as appear in ISO, VDI, and ASTM documents are discussed and the main parameters influencing the value of the LOD are described. In addition, a concept for calculating a limit of quantification (LOQ) both for air and material analysis is described.