In the determination of the quantity of carbon present in water in the form of organic compounds the carbon-containing water is first evaporated in the presence of oxygen at a temperature of about 900.degree. C. Care must be taken that the oxygen does not exceed 1 to 5 volume %, calculated on the quantity of steam. Then the CO.sub.2 content is measured with a CO.sub.2 analyzer. In a second step the carbon-containing water is measured without oxygen under identical conditions. The quantity of carbon present in water in the form of organic compounds is determined from the measured CO.sub.2 concentrations.
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.
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.
The apparatus and method for measuring the amount of dissolved organic carbon in a sample utilizes an oxidation chamber wherein the dissolved organic carbon is ionized and a separate measuring chamber whereby an oxygen containing gas is pumped between the two chambers. The process water to be measured is used as both the reference water and sample.
Apparatus and processes for water impurity analysis and for impurity analysis of various other liquids as well. Apparatus and processes are provided for physical characterization of liquid drops as a liquid sample builds up and then drops from a sample needle or other source. Liquid drop characterization is through utilization of infrared liquid drop measuring and computer modeling to measure a liquid drop as it builds up and then measures the falling liquid drop. By optically measuring an infrared radiated falling drop, and/or by characterizing the manner by which a sample drop is formed, a very precise way of determining the exact volume of a liquid sample is accomplished. Sample volume is typically directly proportional to concentration levels of the chemical constituent to be measured. By computer modeling, a falling drop can be quantified as to volume, rather than depending on the otherwise standard way of injecting a "known" volume. Infrared-emitting light is shone through a quartz window and is directed onto an infrared detector with an optical filter in the water vapor/liquid band, and measures not only the falling drop, but drop formation as it builds up. The infrared detector provides a signal output representing sample drop measurement, which signal output is input to a computer or microprocessor for processing and display.
