Strategy for determination of LOD and LOQ values - Some basic aspects

The paper is devoted to the evaluation of limit of detection CLOD) and limit of quantification (LOQ) values in concentration domain by using 4 different approaches; namely 3 sigma and 10 sigma approaches, ULA2 approach, PBA approach and MDL approach. Brief theoretical analyses of all above mentioned approaches are given together with directions for their practical use. Calculations and correct calibration design are exemplified by using of electrothermal atomic absorption spectrometry for determination of lead in drinking water sample. These validation parameters reached 1.6 mu g L-1 (LOD) and 5.4 mu g L-1 (LOQ) by using 3 sigma and 10 sigma approaches. For obtaining relevant values of analyte concentration the influence of calibration design and measurement methodology were examined. The most preferred technique has proven to be a method of preconcentration of the analyte on the surface of the graphite cuvette (boost cycle). (C) 2013 Elsevier B.V. All rights reserved.