Determination of Some Major and Trace Elements in Cladodes of Barbary fig (Opuntia ficus-indica Mill.) by X-ray Fluorescence Spectrometry.

Abstract

Barbary fig (Opuntia ficus-indica) has attracted great attention in extensive rural agriculture for its potential agronomic, medicinal, and environmental benefits. However, there is only incomplete information about its chemical profile. Energy-dispersive X-ray fluorescence (EDXRF) spectrometry was applied to determine the concentrations of 11 major and trace elements (Br, Cr, Cu, Fe, K, Mn, P, Rb, Sr, Yb, and Zn) in cladodes of O. ficus-indica and the adjacent soil. For analytical accuracy, the standard reference materials CRM-IAEA 336 (Lichen) and CRM-NIST 1646a (Estuarine Sediment) were used. The relationships between the chemical elements were established by Pearson's correlation coefficient (r) and principal component analysis (PCA). The results show that K, P, Fe, and Mn were the dominant essential elements in O. ficus-indica cladodes; however, Br, Cr, Cu, Rb, Yb, and Zn were present at low concentrations. The cladodes showed high enrichment with K, Sr, and Br (BEF > 1), but the values of this coefficient were below 1 for the remaining elements. The PCA showed that in the O. ficus-indica cladodes, the higher concentrations of Br, K, and Sr were correlated; conversely, the highest contents of Cr, Cu, Fe, Mn, P, Rb, Yb, and Zn were retained in the soil. The present findings enabled us to determine that O. ficus-indica has a high ability to accumulate K, P, Fe, and Mn in its cladodes. Therefore, the data obtained from the analysis of this cactus will be useful for nutritional and medicinal purposes.