Comparison of Minimum Detectable Concentration with the IUPAC Detection Limit

HEMICAL MEASUREMENTS may involve material containing very small amounts of the component of interest. With regard of measurement uncertainty it is often difficult to distinguish such small amounts from zero. Therefore an important performance characteristic of a measurement process is its detection capability, which is usually expressed as the smallest concentration of analyte, represented by the analysed component of the sample that can be reliably distinguished from zero. The decision whether the analyte is or is not present in the laboratory sample is based on the measurement data. The detection decision is provided by a choice between two opposing statistical hypotheses about the sample. The null hypothesis H0 states: “The sample is analytefree”. The alternative hypothesis H1 states: “The sample is not analyte-free”, which is consistent with the statement: “The sample contains a positive amount of the analyte”. Two possible types of decision errors exist in any