caa a22 4500 605465797 CHVBK 20210128100304.0 cr unu---uuuuu 210128e20150601xx s 000 0 eng 10.1007/s00769-015-1134-3 doi (NATIONALLICENCE)springer-10.1007/s00769-015-1134-3 Improving iodine homogeneity in NIST SRM 1548a Typical Diet by cryogenic grinding [Elektronische Daten] [Jan Kučera, Jan Kameník] NIST SRM 1548a Typical Diet has a certified iodine mass fraction value of 0.759mgkg−1, with a rather large expanded uncertainty (relative value 13.6%). This might be due to the iodine inhomogeneous distribution in the pooled food material. We have proven that cryogenic grinding of NIST SRM 1548a (at the temperature of liquid nitrogen) yields a free-flowing material, with the standard deviation due to a random inhomogeneity that is lower (by a factor of 3) compared with the original material. We have also proven that no change in the certified iodine value and no contamination with other elements present (even at the sub-µgkg−1 level) occurred during the cryogenic grinding process. Thus, we have obtained a quality control material that sets up more stringent requirements on the validation and quality control procedures of the measurement of iodine mass fraction in complex food matrices. Springer-Verlag Berlin Heidelberg, 2015 Iodine nationallicence Reference material nationallicence NIST SRM 1548a nationallicence Cryogenic grinding nationallicence Homogeneity nationallicence Kučera Jan Nuclear Physics Institute of the CAS, 25068, Husinec-Řež 130, Czech Republic aut Kameník Jan Nuclear Physics Institute of the CAS, 25068, Husinec-Řež 130, Czech Republic aut Accreditation and Quality Assurance Springer Berlin Heidelberg 20/3(2015-06-01), 189-194 0949-1775 20:3<189 2015 20 769 https://doi.org/10.1007/s00769-015-1134-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00769-015-1134-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kučera Jan Nuclear Physics Institute of the CAS, 25068, Husinec-Řež 130, Czech Republic aut NATIONALLICENCE 700 1- Kameník Jan Nuclear Physics Institute of the CAS, 25068, Husinec-Řež 130, Czech Republic aut NATIONALLICENCE 773 0- Accreditation and Quality Assurance Springer Berlin Heidelberg 20/3(2015-06-01), 189-194 0949-1775 20:3<189 2015 20 769