Combustion as a Feasible Sample Preparation Method for Trace Element Determination

Erico Flores, Chemistry Department, Federal University of Santa Maria, Santa Maria, Brazil (ericommf@gmail.com)

Combustion systems have been extensively used in last years and mainly related to two classical systems, the combustion bomb and the oxygen flask method. In spite of the advantages related to these methods, such as high efficiency of digestion, high sample mass (in the case of the combustion bomb method), and suitability for further halogens determination, relatively few papers have been published in the last ten years using these methods. The reason may be due to the development of more robust microwave-assisted wet digestion systems in closed vessels. These systems operating under high pressure with closed vessels have provided several benefits when compared to the conventional combustion methods. In spite of some advantages, wet digestion methods still need additional development, mainly for the subsequent determination of some elements, and for the digestion of some materials, such as coal, carbon nanotubes, and graphite.  Especially for these samples that are hard to digest, combustion methods in closed vessels provide a convenient way to obtain low carbon content in digests. An important improvement in combustion methods was the development of the microwave-induced combustion (MIC) system. This method was designed to combine in the same system the main features of conventional microwave-assisted wet digestion with those of classical combustion methods in closed systems. This system allows the complete digestion of some kinds of samples, such as carbon nanotubes, crude oil, graphite, petroleum coke, and polymers, using relatively high sample masses and achieving low residual carbon content in digests. In addition the digestion time is decreased and digests are suitable for further determination of metals and nonmetals. On these aspects, the recent applications of MIC for a variety of matrices will be presented and the main aspects of sample preparation for the determination of metals and halogens will be discussed.

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Short Biography of Presenting Author

He has a permanent position at Federal University of Santa Maria/Brazil and is the Scientific Director of Rio Grande do Sul State Research Foundation. He was the Director of Analytical Chemistry Division of Brazilian Chemical Society and has experience in the development of methods for sample preparation, speciation analysis and quality control using atomic spectrometry with more than 300 papers, book and book chapters. He developed a new system of microwave induced combustion that is commercialized in many countries, is a titular member of Deliberative Council of Brazilian Pharmacopoea, editor or member of Editorial Board of scientific journals and Vice-president of Analytical Chemistry Divison of IUPAC. He has more 5000 citations and H-index of 37.