How much liquid is left after wet digestion?

2ml. Wet digestion: Take 0.5g of edible oil sample, add 2 ml of sulfuric acid, 3ml of perchloric acid and 5ml of nitric acid, first digest at low temperature, and gently shake the triangular flask. After the reaction was stable, a large number of fine bubbles appeared on the liquid level in the flask, and there were reactant centers. Do not drip too fast, so as not to slow down the cooling rate and make the solution transparent. Stop shaking the flask. At this time, the liquid in the flask may appear brown again, which is the process of digestion of refractory organic matter, and continue to digest until the liquid in the flask emits sulfuric acid smoke.