Determination of carbon dioxide in gaseous samples by gas diffusion-flow injection

Abstract

A gas diffusion-flow injection system was developed for the determination of carbon dioxide in gaseous samples. The calibration was based on the use of either gaseous carbon dioxide or aqueous sodium carbonate standards. Gaseous carbon dioxide samples and gaseous or aqueous standards were injected directly into a donor stream of 1.0×10-4M H2SO4. In the gas diffusion unit, carbon dioxide diffused through a PTFE membrane into an acceptor stream containing a mixed acid/base indicator. The absorbance of the acceptor stream was monitored spectrophotometrically at 554nm. The calibration plot was linear over the range of 5.00×102 to 1.27×104μll-1 with a sample throughput of 28h-1 and 3.2% R.S.D. ([..