If ashing aids, e.g. sulphuric acid, magnesium nitrate, magnesium oxide are added to the sample, higher ashing temperatures can be used without losses of the elements of interest. However, use of ashing aids may cause dissolution problems of the ash.
Organic compounds containing arsenic can be very stable and require a very thorough oxidative decomposition procedure to ensure that correct results for total As are obtained. Wet digestion must include and bomb digestion must be followed by a final digestion step with perchloric acid, hydrogen peroxide or other strong oxidizing reagents like potass permanganate. Dry ashing with a mixture of magnesium nitrate/magnesium oxide as ashing aids also is suitable for arsenic determinations.
