PARTICLE-SIZE DETERMINATION OF SOME IAEA AND NIST ENVIRONMENTAL AND BIOLOGICAL REFERENCE MATERIALS

Particle size distributions in fifteen International Atomic Energy Age ncy (IAEA) and sixteen National Institute of Standards and Technology (NIST) reference materials (RMs) were measured with the basic aim to i nvestigate the potential of these materials to be used as reference or quality control materials in analyses where a small sample mass is re quired (< 100 mg). Most of the investigated materials are commercially available environmental or biological natural matrix RMs with certifi ed values for trace elements, radionuclides, or organometallic compoun ds. The laser diffraction technique was used in all measurements. From the point of particle size distribution, materials IAEA-390 (Algae, a set of three materials), IAEA-396m (Urban Dust, 3x air jet milled), N IST-SRM 1515 (Apple Leaves), NIST-SRM 1547 (Peach Leaves), NIST-SRM 15 66a (Oyster Tissue), NIST-SRM 1570a (Spinach), NIST-SRM 1573a (Tomato Leaves), and NIST-SRM 1648 (Urban Particulate) can be considered appro priate for small sample mass analysis. However, additional analytical tests are needed to confirm the appropriate homogeneous distribution o f chemical composition, the level of heterogeneity for individual elem ents, at this sample mass level.