“…Kinson and Belcher (1975) have expressed the view that provided mineral matter content is determined directly (e.g., by low-temperature ashing in an oxygen plasma; Miller et al, 1979), and provided all of the above steps are taken, the value for oxygen-by-difference should be good to ± 0.3%. The mineral matter can then be subtracted out if one wants the composition of the pure organic substance, or it can be left in if one wishes to use the analysis in following the effects of a chemical reaction.…”