What Does Limit of Detection (LOD) Mean?
The Limit of Detection (LOD) is typically defined as the lowest concentration or quantity of a component or substance that can be reliably distinguished with a specific analytical method. Instinctively, the LOD would be the lowest amount of concentration that is obtained from measuring a sample that contains the component that we would be able to differentiate from the concentration that has been obtained from a measured blank sample (one which doesn’t contain the component).
The LOD is used to express the lowest concentration of an analyte that can be detectable by a specific instrument, method or sample. If a measured sample is found to have a concentration that is lower than this value or gives a reading that cannot be distinguished from the set reference point, the best that we can confidently say about the sample is that the existing analyte is below the LOD.
However, you can never assert that the sample doesn’t completely contain the analyte in question because there is always a possibility, however bleak, that it does, but not in amounts that can be sufficiently detected.
The LOD may also be referred to as lower limit of detection or the detection limit.