Is extraction of Fe from iron based reference materials an appropriate method for determination of trace elements?

Abstract

<jats:title>Abstract</jats:title> <jats:p>Various trace elements in different types of iron based geological reference materials [JSS 804-1 (hematite), JSS 820-2 (limonite), SU-1 and SU-1a (iron-nickel-copper-cobalt ores)] were investigated using <jats:italic>k</jats:italic> <jats:sub>0</jats:sub>-instrumental neutron activation analysis (<jats:italic>k</jats:italic> <jats:sub>0</jats:sub>-INAA). To avoid the interference of iron as the matrix element, a liquid–liquid extraction procedure with diisopropyl ether (DIPE) in hydrochloric acid solution and determination of trace elements in the inorganic phase was undertaken prior to irradiation. The <jats:italic>k</jats:italic> <jats:sub>0</jats:sub>-INAA method, applied to determine the content of the investigated elements, enabled the distribution of 39 elements to be followed through their corresponding intermediate/medium and long half-lived radionuclides. The possibility of determining the content of numerous trace elements after Fe separation is an important advantage of the proposed method. <jats:italic>k</jats:italic> <jats:sub>0</jats:sub>-INAA used to determine element s in the powdered materials and in liquid form after iron extraction enabled us to follow the losses and potential contamination of some elements in the liquid–liquid extraction process. Additionally, elimination of the matrix element lowered the detection limit for some trace elements compared to their corresponding values obtained by <jats:italic>k</jats:italic> <jats:sub>0</jats:sub>-INAA.</jats:p>