Abstract: Total organic carbon can be determined for each one of a plurality of discrete aqueous samples containing halide ion by means of an apparatus comprising a reactor (13), and a pump (12) and flowline (11) for introducing a continuous flow into the reactor (13) of a solution that contains an oxidizing agent and mercuric monohalide ion without forming an insoluble precipitate. The solution to be introduced into the reactor (13) is prepared by mixing the oxidizing agent with a solution containing mercuric monohalide ion; and the solution containing mercuric monohalide ion is formed by adding a quantity of mercuric halide and a quantity of mercuric nitrate to an aqueous solution containing nitric acid, where the molar concentration of the mercuric halide is at least equal to the molar concentration of the mercuric nitrate.

Abstract: Total organic carbon in an aqueous sample containing halide ion is determined by preparing an aqueous solution containing an oxidizing agent and mercuric monohalide ion without forming an insoluble precipitate, introducing the sample into the solution so formed, irradiating the solution and sample with ultraviolet energy to oxidize organic matter in the sample to produce carbon dioxide, sparging the carbon dioxide so produced from the solution, and measuring total carbon in the carbon dioxide. The aqueous solution is prepared by mixing the oxidizing agent with a solution containing mercuric monohalide ion, which is formed by adding a quantity of mercuric halide and a quantity of mercuric nitrate to an aqueous solution containing nitric acid, where the molar concentration of the mercuric halide is at least equal to the molar concentration of the mercuric nitrate.