A measuring apparatus for determining the total organic carbon of a sample in a liquid medium includes a reactor block made of a metallic, electrically conductive, and corrosion-resistant material, the reactor block including a housing wall for accommodating a light source, the housing wall including an inlet into and an outlet from the reactor block and a flow chamber in which digestion of the sample for determining the total organic carbon occurs, the flow chamber configured to accommodate the light source and to route the sample to be irradiated with light, wherein the measuring apparatus further includes at least one conductivity measurement device, wherein the reactor block is an external electrode of the conductivity measurement device. A method for determining the total organic carbon of the sample using the measuring apparatus is disclosed.

A method for determining the total organic carbon in a sample which includes mixing the sample with a reagent containing at least one acid effective for reacting with inorganic carbon-containing materials in the sample, and at least one oxidizing agent effective for oxidizing organic carbon-containing materials in the sample in the presence of ultraviolet radiation, and detecting the carbon dioxide generated, is described. The at least one acid may include phosphoric acid, while the oxidizing agent may include sodium persulfate. In accordance with an embodiment of the inventive concept, the sample is first injected into a reaction chamber, which is continuously flushed with carbon dioxide free gas with no UV light present, and CO.sub.2 generated from any inorganic carbon in the sample as carbonates is flowed through the detector, and may be recorded. Subsequent to this step, the UV light is passed through the reaction chamber and CO.sub.2 generated from the reaction of the at least one oxidizing agent with the organic material in the solution in the presence of ultraviolet radiation, is flowed through the detector, which may be a non-dispersive infrared detector, after the reaction chamber is sparged using a carbon dioxide free gas, and recorded.

A measuring apparatus for determining the total organic carbon of a sample in a liquid medium includes a reactor block made of a metallic, electrically conductive, and corrosion-resistant material, the reactor block including a housing wall for accommodating a light source, the housing wall including an inlet into and an outlet from the reactor block and a flow chamber in which digestion of the sample for determining the total organic carbon occurs, the flow chamber configured to accommodate the light source and to route the sample to be irradiated with light, wherein the measuring apparatus further includes at least one conductivity measurement device, wherein the reactor block is an external electrode of the conductivity measurement device. A method for determining the total organic carbon of the sample using the measuring apparatus is disclosed.

In one embodiment, determining carbon system parameters of water includes measuring the pH of a first subsample of the water using a spectrophotometer, adding nitric acid as a titrant to a second subsample of the water to obtain a titrated subsample, measuring a concentration of added nitric acid in the titrated subsample using a spectrophotometer, measuring the pH of the titrated subsample using a spectrophotometer, and calculating one or more unknown carbon system parameters using the pH of the first subsample, the pH of the titrated subsample, and the concentration of added nitric acid of the titrated subsample.

A high-resolution in situ sensing system and method for providing continuous measurements of at least one dissolved analyte including a sample processing cell having at least a first conduit defining a first passage with at least one selectively-permeable wall capable of passing a portion of the sample liquid into a processing, fluid. The at least one selectively-permeable wall substantially resists flow of another portion of the sample liquid therethrough. Processing fluid is directed through the first conduit while moving the sample liquid and the reagent fluid relative to each other in one of a stationary, concurrent or a countercurrent flow relationship to achieve either partial or full equilibration between the sample liquid and processing fluid to generate at least partially equilibrated reagent fluid and a processed sample in a substantially continuous manner.

Provided are a total organic carbon measurement method and a total organic carbon measurement device capable of determining whether or not an acid has been added to a sample. An acid is introduced into a reaction unit in which the sample is placed from a reservoir in which the acid is reserved (step S103). The conductivity of the sample into which the acid has been introduced is measured (step S105). The introduction of the acid from the reservoir into the reaction unit is detected on the basis of a change in the conductivity of the sample (step S107).