Determination of Al,B and 11 Other Trace Elements in Plants by Inductively Coupled Plasma-Atomic Emission Spectrometry:Comparison of Five Different Sample Digestion Procedures

For accurate determination of nutritional and toxic elements in plants by means of inductively coupled plasma atomic emission spectrometry (ICP-AES), sample preparation is a critical phase. Although some procedures such as dry ashing in a muffle furnace or wet digestion with HN0₃-HC10₄ on a hot plate have been available for many years, growing interest has been focused on the use of microwave-based digestion in recent years. Compared to the classical digesting procedures, microwave digestion has some significant advantages:the digestion is carried out in closed vessels so that the contamination and the loss of volatile elements are markedly minimized; the digestion is less time consuming due to the elevated pressure and temperature within the vessels. In addition, the use of polytetrafluoroethylene (PTFE) vessels for microwave digestion makes it both easy and safe to employ very corrosive reagents, such as HF.