Wet ashing is primarily used in the preparation of samples for subsequent analysis of specific minerals (see later).� It breaks down and removes the organic matrix surrounding the minerals so that they are left in an aqueous solution.� A dried ground food sample is usually weighed into a flask containing strong acids and oxidizing agents (e.g., nitric, perchloric and/or sulfuric acids) and then heated.� Heating is continued until the organic matter is completely digested, leaving only the mineral oxides in solution. The temperature and time used depends on the type of acids and oxidizing
Advantages: Little loss of volatile minerals occurs because of the lower temperatures
Advantages: Less chance of losing trace elements by volatilization
Disadvantages: Relatively expensive equipment and small sample throughput.