Enviromental regulation and safety concerns restrict the used of perchloric acid in some laboratories. Dry ashing is an alternative to perchloric acid for oxidation of refractory organic compounds. dry ashing is simple and most food laboratories have the required equipmeant. Arsenic and selenium, however, are subject to loss by volatilization if test portions are allowed to char or ignite during ashing. Magnesium nitrate and magnesium oxide are commoืly employed as ashing dry ashing, Brumbaugh and walther oxidized potentially volatile analyte species with a nitric acid predigestion. Foster and Sumar eliminated foaming that occurred during open-vessel wet oxidation by utilizing a nitric acid microwave digestion before dry ashing