Absolute standard reference materials for low-level concentration measurements

摘要

A concentration measurement device is calibrated for a target element by performing a concentration measurement on a reference standard sample which includes a number of atoms of a radioactive marker element in known ratio to a number of atoms of the target element. Both the ratio of atoms of the target element to those of the radioactive marker element and a count of decay products of the radioactive marker element are analytically quantified. Because the count of decay products is correlated with the number of atoms of the radioactive marker element, the ratio and the count of decay products are used to accurately calculate the otherwise unknown number of impurity atoms and to calibrate a concentration measurement signal from the concentration measurement device.