Need and use of reference materials in a comprehensive countrywide monitoring of radionuclides

The reliability of measurement results is essential for forming a common database of a laboratory network, because a well-maintained and consistent database is the crucial point of countrywide monitoring. Reference materials are important tools in realizing some aspects of quality assurance; they are especially useful in harmonizing work within the network. Among usual types of reference materials in radio analytics solutions, matrix reference materials and some special reference objects are used. All classes of reference materials should be used depending on the purpose of the demonstration of quality, even in-house reference materials. Interlaboratory measurement comparison and performance evaluation programs play important quality assurance role in radio analytical laboratories. Fortunately, nowadays, the main task is to determine a very low radioactivity concentration in the environment; therefore, pre-concentration is necessary. Generally, the radionuclide bearing natural materials collected from sites where there had been sufficient time for natural processes to redistribute various chemically different species of radionuclides are more reliable reference materials than spiked materials—the main difference is the chemical bounding which is crucial from the point of view of the bioavailability. The need of reference material is summarized according to the intended use, like quality control, measurement validation, and instrument calibration.