Elemental analysis of Maerua subcordata (Gilg) DeWolf using ICP-MS
Abstract
Elemental analysis of botanicals is performed to characterize the amounts of essential metals or to ensure that the levels of unavoidable metals will not exceed maximum permissible limits (MLs). Since mineral elements are considered micronutrients, no official MLs are set. Instead, tolerable upper intake levels (ULs) are used to regulate adverse health effects related to possible excess intake. This study determined the levels of four toxic elements ( As, Cd, Hg, and Pb ) and eight essential elements ( Co, Cu, Fe, Mg, Mn, Mo, P, and Zn ) in dried powders of the fruit, leaf, root tuber, and seeds of Maerua subcordata using inductively coupled plasma mass spectrometry (ICP-MS). In all analyzed samples, the concentrations of toxic metals were low enough not to raise safety concerns, and there were no safety concerns related to potential intake above ULs of the essential elements. While the concentrations of Co, Cu, and Zn were low enough not to raise safety concerns or provide significant nutritional contribution, significant concentrations of Fe, Mg, Mn, and Mo in the leaf part and Mg and Fe in the root part were identified. In conclusion, this study revealed for the first time that the concentrations of toxic metals in different parts of M. subcordata do not raise safety concerns, while significant concentrations of some elements were detected mainly in the leaf part, showing possible health and/or nutritional implications. Yet, further studies to characterize the actual bioavailability and potential health impact of each element in the respective matrices may be recommended.