oxygen-flask combustion

in spectrochemical analysis
In order to determine elements which are easily volatilized, or are present as volatile species, organic material may be ashed in oxygen in a closed oxygen combustion system. One such method is oxygen-flask combustion by which the test sample is burned in a closed flask containing oxygen and an absorbing solution in which the analytes are subsequently determined.
Source:
PAC, 1988, 60, 1461 (Nomenclature, symbols, units and their usage in spectrochemical analysis-X. Preparation of materials for analytical atomic spectroscopy and other related techniques (Recommendations 1988)) on page 1468