With a limit of detection one intends to characterize the capability of a method or instrument to detect the analyte of interest.The following comments seem to be in order: Mercuroĭownload from the Spectroscopy Online site ( =129 kB) will continue to stimulate efforts to characterize sophisticated instruments with a realistic estimate of their detection capability.Ī good introduction of some relevant concepts is provided by the following tutorial: One expects that the ever-increasing concern with respect to food safety, the environment, 'clean' sports, &c. It is of vital importance in trace analysis. The limit of detection is an analytical figure of merit that, owing to the complex statistics involved, deserves a separate treatment. G eneralization to multivariate and beyond.
The straightforward, theoretically sound and cost-effective chemometrics alternative is to utilize suitable calibration models. These conditions can often be avoided by a specific sample pretreatment and/or sufficiently expensive instrumentation. In other words, the signal data are non-selective for the analyte of interest and the blank signal varies. direct overlap) and non-spectral interferences (e.g. The purpose of this page is to review the progress made concerning limit of detection estimation in the presence of varying spectral (i.e. It is, for example, quite possible to detect the analyte when its actual level is below L D, since the result should be compared with L C, not L D.Īdmittedly, this definition is complicated because hypothesis testing usually involves the distribution of potential results under the null-hypothesis only.įigure LOD 1: The detection decision takes place at the critical level (L C), not at the limit of detection (L D)! The proper values are of course problem-dependent. Given this critical level, the limit of detection (L D) is construed as the level that will lead to false non-detects with probability b.Ĭommon values for a and b are 1% and 5%. Taking the detection decision at the critical level (L C) leads to a risk a of false detects. Probably much to the chagrin of practitioners, the official definition of limit of detection is not really simple: