Preparation of Natural Standard Reference Material (SRM) for Ellajjun Oil Shale/Jordan

The standard reference materials (SRMs) represent a key tool for the quality control of chemical analyses and the demand on these materials is constantly increasing worldwide. A standard reference material of oil shale (SJL-1) collected from El-lajjun area in Jordan was prepared and certified to be used for quality control of analyses and calibration particularly for the oil shale characterization and testing laboratories. This work was a part of the Arab collaborative projects initiated by Arab Atomic Energy Agency (AAEA) during the period from 2007 to 2009. The paper describes the certification procedure and the inter-laboratory comparison study results, which was carried out through participation of twelve national and international laboratories applying eleven different analytical techniques used to determine the analytes concentration. Details of the production, homogeneity and stability of SJL-1 standard reference material were reviewed as well as the results of certification. The Certificate of Analysis for SJL-1 provides assigned certified values for almnuium oxide, phosphorus pentoxide, calcium oxide, titanium dioxide, magnesium oxide, potassium oxide, ferric oxide, sodium oxide, manganese oxide, sulfur, uranium, vanadium, chromium, zinc, nickel, copper, and strontium. Reference values are provided for Loss on Ignition (LOI), silicon oxide, cadmium, molybdenum, cobalt, lead, barium and arsenic. Finally, range values are assigned for other thirty-seven constituents of oil shale.