Planning and certification of new multielemental reference materials for research in antarctica

Abstract

The adoption of the principles of Good Laboratory Practice (GLP) and the implementation of the ensuing procedures for quality assurance (QA) and quality control (QC) of analytical determinations are nowadays deemed essential to the achievement of sound, credible and comparable experimental information. This is certainly also applicable to research projects currently being carried out in the antarctic continent, in particular as regards investigations on global change phenomena. Worldwide investments made so far in this field do require in fact that reliability of data be optimized so as to allow for a harmonized assessment of ongoing trends. In this context the Italian National Programme for Research in Antarctica has recently launched a project for the preparation of new multielemental certified reference materials (CRMs) to be used for QC of analyses performed on environmentally significant materials. The suitability of CRMs to verify the accuracy of experimental measurements acknowledgedly depends, among others, on the degree of similarity of their matrix composition and analyte levels to those expected for real samples. From this standpoint three CRMs are planned, namely: i) marine sediment certified for Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sn and Zn; ii) ocean water certified for Cd, Cr, Cu, Fe, Hg, Mn, Ni and Pb; iii) krill certified for As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sn and Zn. Regarding the first two matrices, amounts of ca. 100 kg and ca. 1001, respectively, have been collected during the IX (1993–1994) antarctic expedition, while krill was taken in the course of the X (1994–1995) campaign. The pretreatment of sediment has been accomplished in terms of homogenization, stabilization and characterization of the preliminary ground mass. Approximately 500 bottles, each containing 75 g of material are now ready for distribution to interested laboratories involved in chemical measurements of antarctic matrices, whereas ocean water and krill will follow at a later stage. Finally, depending on circumstances, also the certification of organochlorine compounds in the same materials will be attempted.