A Method for Determining Total Carbon Dioxide in Small Volumes of Liquid

Abstract

A microdiffusion method for estimating total dissolved carbon dioxide in volumes of approximately 1·5 μl. is described. The principle of the method is to displace the CO2 with acid, to absorb it in barium hydroxide solution and to measure the change ;n the freezing-point depression of this solution. The range of measurement is 0–30 mm/1. HCO3− with a standard deviation of ± 0·3–0·4 mm/1. In its present form the method cannot be used with smaller volumes without correcting for errors arising from the diffusion of water vapour between the sample and the barium hydroxide solution.