Ashing, also known as dry ashing or incineration, is a thermal process where a sample is subjected to high temperatures (typically between 450°C to 800°C) in a controlled environment, to oxidize organic components and obtain an inorganic ash residue. Cold plasma ashing is a variant of the traditional process that uses a plasma source for the oxidation, leading to operate in a low temperature environment. The use of pure oxygen minimizes contamination risks, however loss of volatile elements during the process may occurr. Ashing offers distinct advantages over microwave-assisted digestion of PC filters which are completely ashed, increasing the signal-to-background ratio and enhancing the analytical sensitivity and accuracy of TXRF analysis . Specifically, cellulose acetate filters are chosen for their ability to be decomposed by oxygenplasma .