Comparison of detection limits in environmental analysis - is it possible?An approach on quality assurance in the lower working range by verification

Detection limit, reporting limit and limit of quantitation are analytical p arameters which describe the power of analytical methods. These parameters are used for internal quality assurance and externally for competing, espec ially in the case of trace analysis in environmental compartments. The wide variety of possibilities for computing or obtaining these measures in lite rature and in legislative rules makes any comparison difficult. Additionall y, a host of terms have been used within the analytical community to descri be detection and quantitation capabilities. Without trying to create an ord er for the variety of terms, this paper is aimed at providing a practical p roposal for answering the main questions for the analysts concerning qualit y measures above. These main questions and related parameters were explaine d and graphically demonstrated. Estimation and verification of these parame ters are the two steps to get real measures. A rule for a practical verific ation is given in a table, where the analyst can read out what to measure, what to estimate and which criteria have to be fulfilled. In this manner ve rified parameters detection limit, reporting limit and limit of quantitatio n now are comparable and the analyst himself is responsible to the unambigu ity and reliability of these measures.