What Can Be Detected

The characteristics of an analytical method are dynamic. The state of the apparatus and of the operator, the laboratory environment, and the level and type of contaminants present in the sample are examples of such characteristics. Detectability, which concerns functioning of an analytical method near its natural limit of sensitivity, is particularly dependent on dynamic characteristics. At the instant of analysis, past history only determines these characteristics in a frequency sense. Probability theory provides a tool for deciding what can be detected by using frequency-type information to define the characteristics of the analytical method.