How can carbon dioxide be measured in a gravimetric analysis of a mineral?

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In gravimetric analysis, the amount of carbon dioxide in a mineral is determined by converting the carbonate content into a gaseous form.1

The process follows these steps:

Acid Treatment: The mineral sample is treated with an acid, which causes the carbon dioxide to be evolved as a gas.1
Absorption: The evolved gas is passed through and absorbed by a weighed quantity of a solid alkaline reagent.1
Calculation: The total amount of carbon dioxide present in the original sample is determined by measuring the gain in weight of the absorbent.1

This method relies on the principle of isolating a constituent by converting it into a substance of known composition that can be accurately weighed.1