Determination of operationally defined fractions of aluminium in reference materials and acid attacked environmental samples

The aim of the presented work is to evaluate the selectivity of the operationally defined procedures for the aluminium fractionation in the reference materials and the environmental samples affected by the mining activity. The combination of the sequential optimized BCR (European Commission Community Bureau of Reference) three-step, the single (H₂O, CaCl₂, Na₂S₂O₄, NH₄F, (NH₄)₂C₂O₄, HCl, NTA, EDTA, DTPA) and the solid phase chelating ion-exchange extraction procedures was performed for the aluminium fractionation in the samples. The amount of the reactive Al determined by the solid phase extraction on the chelating resin Iontosorb Salicyl is the most important operationally defined fraction of aluminium from the aspect of its negative effects on the environment. The available Al concentrations obtained from the different operationally defined fractionation methods were compared. The flame atomic absorption spectrometry was used for the aluminium quantification. The X-ray diffraction analyse of the samples was performed for the mineral composition determination.The precision, the repeatability and the accuracy for the all steps of the optimized BCR sequential extraction procedure were checked on six reference materials (SRM 2710, RSS SO-2, RSS SO-4, CRM SA-B, SRM RTH 912, CRM 025-050). The precision and the repeatability were very good with the R.S.D. values ≤11%. The fraction specific accuracy was excellent. The new indicative fractional Al values in the used reference materials are published.