I have been wondering if the 99.9995% pure O2 required for burning in a CHNS analyzer could be substituted by a pure, solid oxidizer such as barium or sodium peroxide.

There are downsides to this, such as the need to carefully weight the oxidizer (100 to 500mg depending on the peroxide) in order to guarantee repeatability, or the increase in ash accumulation in the crucible, requiring more frequent cleaning. But my main worry is the possibility of damage to the equipment due to rapid expansion in the decomposition. Any thoughts?