Internal and external quality control procedures applied for k_0-neutron activation analysis laboratory using Es-Salam research reactor

摘要

The quality control in a nuclear analytical technique such as neutron activation analysis is based on internal and external quality assessment with so called indicators of laboratory quality. This paper addresses the quality assessment applying the single laboratory approach and the inter-laboratory comparison approach including Z_(score) and U_(score) indicators. The elemental concentration of several types of reference materials such as standard reference materials (SRMS); NIST1573a (tomato leaves), NIST1646 (estuarine sediment) and NIST1566b (oyster tissue), Reference Materials (RMs) of IEA; Soil7, Sl1, Lichen336, 140/TM, Certified Reference Materials (CRMs); GSV4 (Tea leaves) and GSD12 (stream sediment) and SMELS (Synthetic Multi-Element Standards) II and III have been determined by the k_0-NAA method and evaluated by means of statistical parameters measured as deviations from certified/recommended values, Z and U scores. The concept of external evaluation was considered and carried out within the framework of the AFRA/RAF projects. The Proficiency Testing tests related to the determination of major, minor and trace elements in forty materials of the International Soil and Plant Analytical Exchange (WEPAL codes ISE, IPE), were held during 2011-2015. All results were evaluated and reported in this paper.