Microwave-Induced Combustion Digestion of Petroleum Coke Samples

Researchers at Universidade Federal de Santa Maria (Santa Maria, Brazil) and Centro de Pesquisas e Desenvolvimento Leopold Americo Miguez de Mello-CENPES/PETROBAS (Rio de Janeiro, Brazil) analyzed chloride in petroleum coke samples using microwave-induced combustion followed by ion chromatography. The digestion took place in closed vessels with samples pressed as pellets and placed on a quartz holder. The researchers used an oxygen pressure of 2 Mpa and a 50-µL volume of 6 M ammonium nitrate as an ignition aid for combustion.