In this study, it was developed a method for Ca, Mg, Mn, Fe and Zn determination in palm oil samples by flame atomic absorption spectrometry (FAAS) after ultrasound-assisted emulsification and extraction induced by emulsion breaking (EIEB). Optimization of the method was carried out by a constrained mixture design. The developed method has presented limits of detection (LOD) between 0.012 and 0.057 mg L-1, limits of quantification (LOQ) between 0.039 and 0.19 mg L-1 and precision was expressed as repeatability (%RSD, n = 10) between 1.8 and 3.2% for the five studied metals. Method accuracy was assessed by the application of recovery tests (87 to 113%) and by comparison of concentration values with the dry ashing method, showing good agreement with the standard method. The developed methodology allows operational simplicity, multi-sample treatment, and low cost when compared with some methods based on decomposition. It was applied in palm oil samples collected in the Bahia State (Brazil). The concentrations (in mg L-1) found in the samples were: 3.93-13.9 Ca, 0.37-2.26 Mg, > LOQ-0.32 Mn, 1.77-8.57 Fe and 0.38-2.54 Zn.
Keywords:
palm oil; extraction induced by emulsion breaking; metals; FAAS
