Abstract: An apparatus is disclosed which is capable of detecting a selected gas in a liquid sample to a sensitivity in the range of 10 to 10,000 parts per trillion. Such sensitivity is achieved by concentrating the selected gas in a sample without concentrating sources of ionic interference that are also present in the sample. Selective concentration of the gas is achieved by vaporizing the sample, correcting for non-ideal vaporization, selectively condensing the selected gas from the vapor, and detecting the selected gas. Methods for using the apparatus and detecting the selected gas are also disclosed.

Abstract: A method and apparatus for measuring the amount of carbon and other organics in an aqueous solution is disclosed. A novel multistage reactor employs ultraviolet radiation to promote oxidation of a test sample. Oxygen and an oxidizing agent such as sodium persulfate are introduced into the solution prior to irradiation. The mixture is brought into direct contact with an ultraviolet lamp in each stage of the reactor. The design of the multistage reactor permits the desired chemical reaction to be optimized over interferring reactions.An inorganic carbon scrubber assembly is also disclosed for operation in a total organic carbon mode.