Evaluation of a simple and fast method for the multi-elemental analysis in commercial fruit juice samples using atomic emission spectrometry

Abstract

Four sample preparation procedures: wet digestion with HNO3/H2O2 (P1), 1:1 dilution with 2% HNO3 and latter centrifugation (P2) or filtration (P3) and direct analysis after centrifugation (P4) for the determination of total Al, Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, P, Pb, Sr and Zn in fruit juices by inductively coupled plasma atomic emission spectrometry (ICP OES) were compared. Precision (RSD), accuracy (by standard addition or recovery) and limit of detection (LOD) were used to evaluate characteristics of the procedures. Dilution with 2% HNO3 and centrifugation (P2) provided the best results, i.e. LODs between 0.11 and 108 ng mL(-1), RSDs of 1% and 5% and accuracy better than 5%. This procedure was also simple, fast and could be applied for routine analysis. Element concentrations agreed with those after wet digestion, therefore the procedure can be alternatively used instead of conventional sample treatment. Several commercial juices were analysed with this procedure.

Keywords: Fruit juices; ICP OES; Major and trace elements; Sample preparation.