1. SW-846 EPA method 3051A: Microwave assisted acid digestion of sediments, sludges, soils and oils, Revision 1, U.S. EPA Washington, DC, February 2007.
2. SW-846 EPA method 3052: Microwave assisted acid digestion of siliceous and organically based matrices, Revision 0, U.S. EPA Washington, DC, December 1996.
3. Characterization of waste. Microwave assisted digestion with hydrofluoric (HF), nitric (HNO3) and hydrochloric (HCl) acid mixture for subsequent determination of elements, EN 13656:2003, Finnish standards association SFS.
4. Experience with the sources of contamination when preparing samples for the analysis of trace elements
5. Rapid destruction of plant material with concentrated nitric acid vapour (vapour phase oxidation)