Essential and Potentially Toxic Elements from Brazilian Geopropolis Produced by the Stingless Bee Melipona quadrifasciata anthidioides Using ICP OES

Melipona quadrifasciata anthidioides is a species of stingless bee popularly known in Brazil as "mandacaia". Products derived from bees for food and therapeutic uses, have stimulated the evaluation of the chemical composition of geopropolis. Concentrations of 24 essential and potentially toxic elements were determined in geopropolis samples, using a sequential optical emission spectrometer with inductively coupled plasma (ICP OES) after microwave-assisted acid digestion. Principal component analysis (PCA) and Hierarchical cluster analysis (HCA) were used to carry out an exploratory analysis of the samples. The following elements were quantified (in mg Kg(-1)): Al (320,414.40-36,911.1), As (<LoQ-4.37), Ba (38.36-211.11), Ca (672.38-94,527), Co (<LoQ-14.12), Cr (17.41-38.07), Cu (10.63-28.73), Fe (21,973.96-11,536.47), K (1974.38-9198.91), Mg (1961.17-7481.79), Mn (50.51-310.51), Na (154.55-340.46), Ni (2.28-21.74), P (16.59-51.07), Pb (3.45-8.55), Sb (<LoQ-1.64), Se (<LoQ-1.01), Sn (4.92-16.14), Sr (9.21-36.29), V (28.77-78.73) and Zn (24.34-50.31). Cd and Mo were found to be below the limit of detection (LoD) and quantification (LoQ) values of ICP OES in all investigated samples. Geopropolis can be a potential source of macro- and microelements for colonies and products derived from these bees for human consumption, contributing to their geographical origin and quality control, besides being an indicator of environmental monitoring.