Standardizing Methods

Standardizing Methods

The American Chemical Society’s Committee on Environmental Improvement de- fines standardization as the process of determining the relationship between the measured signal and the amount of analyte. A method is considered standardized when the value of k in equation 5.1 or 5.2 is known.

In principle, it should be possible to derive the value of k for any method by considering the chemical and physical processes responsible for the signal. Unfortu- nately, such calculations are often of limited utility due either to an insufficiently developed theoretical model of the physical processes or to nonideal chemical be- havior. In such situations the value of k must be determined experimentally by ana- lyzing one or more standard solutions containing known amounts of analyte. In this section we consider several approaches for determining the value of k. For sim- plicity we will assume that S_reag has been accounted for by a proper reagent blank, allowing us to replace S_meas in equations 5.1 and 5.2 with the signal for the species being measured.