Ultra-low level standard for concentration measurements

摘要

Concentration measurement equipment is calibrated by performing a concentration measurement on a reference standard sample which includes a radioactive marker element. Because a count of decay products can be correlated with the number of atoms of the radioactive marker element, a precise count of decay products of the radioactive marker element is used to calculate an otherwise unknown number of atoms of the radioactive marker element on the reference standard sample. The calculated number of atoms of radioactive marker element is then used to calibrate a concentration measurement of the radioactive marker element by the concentration measurement device. Suitable radioactive marker elements for use in calibrating concentration measurement equipment include Pm-147 and Tc-99. Materials, methods and systems in accordance with the teachings of the invention are useful for calibrating concentration measurements and measurement equipment, including Total X-ray Fluorescence (TXRF) and Time Of Flight-Secondary Ion Mass Spectroscopy (TOF-SIMS) measurements and measurement equipment.