Determination of total organic carbon in a plurality of aqueous samples containing halide ion

摘要

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. The samples are introduced in succession into the reactor (13), either by means of a syringe injection port (19) in the flowline (11), or by means of a rotary valve (203) and sample loop (204) in a recirculation line (202) through which carbon-free liquid is withdrawn from and circulated back to the reactor (13). A mercury vapor lamp (17) is immersed in the liquid in the reactor (13) for irradiating the oxidizing agent and each sample in the reactor (13) with ultraviolet energy in order to oxidize any organic matter in the sample to carbon dioxide. A sparger ( 20) is provided to remove the carbon dioxide so produced from the reactor (13); and a carbon dioxide detector (24) detects the carbon dioxide so removed. Electronic integrator circuitry (25) provides a measure of total carbon in the carbon dioxide produced in the oxidation interval for each sample.