PEP-4D.
Characteristic Limits in Bioassay TR LaBone*, MJW Corp
; NM Chalmers, MJW Corp
Abstract: Characteristic limits are the general term for what we in health physics refer to as the detection level (DL), minimum detectable amount (MDA), and minimum quantifiable value (MQV). The DL and MDA are concerned with our ability to detect an analyte in a sample, whereas the MQV is concerned with our ability to quantify an analyte rather than just detect it. In the first part of this lecture we will discuss how to calculate the a priori DL, MDA, and MQV for an analytical process. This discussion is somewhat atypical because it is presented in terms of the reported result (e.g., mBq/L) rather than the signal (e.g., number of counts in the sample and background) and the use of replicate measurements is covered. In the second part of the lecture, the a posteriori DL, which is used to make decisions about detection for a particular analysis, will be derived using the combined standard uncertainty (csu) for the analysis that is reported by the analytical laboratory and coverage intervals constructed from this csu. As we shall see, this
approach offers many benefits.
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