Microwave Digestion for Determination of Aluminum, Boron, and 13 Other Elements in Plants by Inductively Coupled Plasma Atomic Emission Spectrometry

A microwave digestion procedure was developed for determining aluminum and boron and 13 other elements in plant tissues by inductively coupled plasma atomic emission spectrometry (ICP-AES). The sample (0.5 g) was digested in a closed Teflon vessel with 10 mL concentrated nitric acid and 3 mL hydrofluoric acid, and further digested in an open Teflon vessel with 5 mL hydrogen peroxide. Excess hydrofluoric acid was eliminated by adding 0.2 g silicon (IV) oxide. Four National Institute of Standards and Technology standard reference materials (apple leaves, peach leaves, tomato leaves, and pine needles) were analyzed to test the reliability of the method. The excellent recoveries indicate that the proposed procedure is simple and effective for determination of Al, B, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, P, S, Sr, and Zn in plants.