A device for sparging carbon dioxide from an acidified aqueous stream for use in a system for quantitatively determining the organic carbon content of the stream has a body with vertically extending cavities formed therethrough and passageways which connect the cavities in series so that the aqueous stream travels the length of a cavity before passing into the next. Dispersion tubes are mounted in the cavities for dispersing fine bubbles of sparging gas into the aqueous stream. The gas and carbon dioxide which has evolved from the aqueous stream is collected and discharged through the cavities.