Radiochim. Acta 92, 939–944 (2004)  by Oldenbourg Wissenschaftsverlag, München INAA methodology using low power reactor for the characterization of IAEA-433; Coastal marine sediment as a potential reference material By S. Waheed, A. Rahman, M. Daud, J. H. Zaidi ∗ and S. Ahmad Nuclear Chemistry Division, Pakistan Institute of Nuclear Science and Technology, P.O Nilore Islamabad, Pakistan (Received November 11, 2003; accepted in revised form March 24, 2004) Accuracy / Precision / Certified reference materials (CRMs) / Instrumental neutron activation analysis (INAA) / Marine sediment Summary. As a major requirement for adopting a well- defined quality system for our instrumental neutron activation analysis laboratory regular participation in the IAEA inter- comparison exercises is carried out in routine. IAEA marine sediment (IAEA-433) as a proposed reference material has been studied and thirty elements have been determined em- ploying appropriate irradiation, cooling and counting protocols using instrumental neutron activation analysis (INAA) tech- nique. Employing the same protocols on IAEA SL-1 and IAEA 405 certified reference materials the method has been validated and our values show good agreement with the certified values predicting good accuracy. Miniature neutron source research reactor has been utilized for this work. The results for the IAEA-433 present good precision of less than 5% for Mn, Hf, Sm, Th, Al and Fe whereas for Rb, Tb, V, Se, Ga, Sn and Zn results are with comparatively poor precision ranging 10%–13%. Introduction The pre-requisite of quality assurance in the environmen- tal, industrial, medical and agricultural sectors has enhanced the need for accurate, reliable and reproducible analyti- cal data. In addition, the implementation of World Trade Organization (WTO) protocols by the year 2005 on the global trade/production entails development of strict qual- ity control system. The industrial and trade sector, apart from improving the quality of their produce, will desire high level of confidence on the analytical and chemical test- ing data of their products. Only those laboratories, which adopt proper quality assurance and quality management sys- tems and accredited by a licensed accrediting authority will be able to analyze and certify the export items. Preceding these requirements, best laboratories in the world have ei- ther been accredited or are in a process of accreditation. Our Instrumental Neutron Activation Analysis lab (INAA) at PINSTECH, Pakistan is also in a process of adopting *Author for correspondence (E-mail: jamshed@pinstech.org.pk). a QA/QC system under the guidance of IAEA using inter- national standards of ISO/IEC-17025 [1]. Apart from the regular use of CRM’s according to the ISO Guide 33 [2], regular participation in the analytical quality control exer- cises (AQCS), proficiency tests and analysis of blind control materials is not only desirable but mandatory to maintain the accuracy, precision, and the validation of the technique. Certified Reference Materials (CRMs) represent important benchmark for such quality system that identifies weak methodologies, detecting training needs, upgrading the qual- ity of laboratory performance and assessing the validation of the analytical methods [3]. For most of the aforementioned quality control activities, the use of CRMs is the most appro- priate choice. These materials can be used to determine the accuracy and precision of an analytical technique. Therefore many international, national and professional organizations recommend the use of CRMs in analytical chemistry for quality control purposes. A proper application of CRMs pro- vides the confidence in the quality of the obtained results [4]. The certification of the reference materials can be achieved by analyzing the material by various techniques, individu- als and instruments as possible, which can best be done by launching an interlaboratory comparison programme. Par- ticipation in such Intercomparison programmes also pro- vides the chance to assess the laboratory performance. Following over two decades of our experience in AQCS programmes and the realization of the importance of gener- ating precise and accurate analytical data, our INAA labo- ratory has always set its goal in improving the data quality and attaining the total quality management of the laboratory as a step towards the quality assessment and quality con- trol (QA/QC) for the accreditation of this laboratory. The quality performance of analytical laboratories is directly re- lated to the use of validated or standardized methods [5]. This paper presents the INAA procedures adopted for the de- termination of thirty trace elements for the intercomparison exercise of proposed reference material IAEA-433 (marine sediment). A low power 27 kW tank in pool type Miniature Neutron Source Reactor (MNSR) has been used as the neu- tron source throughout this work [6]. The results presented were submitted to IAEA for the certification of this sediment material. The total quality system adopted for the generation of these results in our lab is also discussed. Brought to you by | New York University Bobst Library Technical Services Authenticated Download Date | 5/29/15 1:55 PM