Análise quimiométrica de méis brasileiros

Abstract

In this research, analytical procedures are proposed for the determination of inorganic constituents in honey samples from different Brazilian regions, by using the technique of Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Three different methods of sample preparation were evaluated: dilution with water, acid digestion in block and digestion assisted by microwave radiation. After determination of final acidity and residual carbon content, acid digestion with microwave radiation by using HNO3 2 mol L-1proved to be more appropriate. Next were determined the analyte Se, Mg, Ca, Al, P, Mn, Fe, Cu, Zn, Ba and Pb in sixty honey samples by ICP-MS and the best conditions to these determination such as the need to use the collision and reaction interface (CRI) and the addition of internal standard. The accuracy of this procedure was evaluated using two certified reference materials and recoveries ranged from 82% up to 115%. The results were evaluated using principal component analysis (PCA), but good separations were not well obtained, considering the wide variation in the components of the same class. Besides the determination of different analytes, the samples of honey were also analyzed by Fourier Transform Infrared (FT-NIR), in order to check possible adulteration and identify the regions of origin of the samples. This study used 46 honeys covering all regions of country, unadulterated honey samples and adulterated with glucose, cane sugar molasses and water in different proportions, from 10% to 50% (m m-1) and the results were analyzed using PCA. The results proved that it was possible to verify the feasibility of using the technique of NIR for classification of Brazilian honeys and also in checking the adulteration of honey, especially when the samples were adulterated with water.