5. Mineralization: decomposition of organic matter

Given that most environmental samples contain highly variable proportions of organic matter, it is clear that dissolution of the samples usually analyzed cannot be achieved in a single step using a single reagent. In practice, the number of steps and reagents required is dictated by the composition of the sample. Purely organic samples will generally be mineralized by oxidation followed by digestion of the resulting residue. This same digestion may, however, ensure the dissolution of any initially mineral part of the sample. In most modern processes, only strong acids and hydrogen peroxide are used, in variable proportions and mixtures, for mineralization and dissolution.