Determination of inorganic elements in geopropolis samples by inductively coupled plasma optical emission spectrometry

Abstract

Information on the mineral composition of geopropolis produced by bees native to the Amazon region is of great importance for the chemical characterization of this product. This study aimed to determine the Ca, Cu, Fe, K, Mg, Mn, P, and Zn contents in 22 samples of geopropolis from northern Brazil by inductively coupled plasma optical emission spectrometry (ICP OES). Geopropolis samples were digested in a microwave oven using concentrated nitric acid and hydrogen peroxide and subsequent addition of hydrofluoric acid. The accuracy of the analytical procedures was assessed by elemental determination using certified reference material Poplar Leaves (GBW 07604). Analyte recoveries ranged between 88% and 99%, and there was no statistical difference (p < 0.05) between the determined and certified values. The accuracy of the measurements was evaluated by the addition and recovery test, and the recoveries ranged between 93% and 118%. The results showed high levels of Fe, Ca, Mg, K, and P in the samples. Principal component analysis (PCA) was performed and the results showed that there was better separation and grouping of the samples in relation to the geographic region, indicating that the mineral composition of geopropolis can vary according to the characteristics of the region. Thus, this study reported for the first time information about the mineral composition of geopropolis produced in northern Brazil, which can serve as a database for the characterization of the product in this region.