An embodiment provides a method for measuring an amount of total organic fluoride content of a PFAS containing sample, including: placing a sample comprising a PFAS compound in a measurement device, wherein the measurement device comprises an oxidation cell and a non-oxidation cell, wherein the oxidation cell comprises a boron-doped diamond electrode; measuring, using the measurement device, an amount of total inorganic fluoride of the sample before an oxidation; applying an electrical potential to a portion of the sample in the oxidation cell, wherein the electrical potential oxidizes the PFAS compound; measuring, using the measurement device, an amount of total organic fluoride of the sample after the oxidation to provide a measurement signal of the total organic fluoride; and determining a first derivative of the measurement signal of the total organic fluoride. Other aspects are described and claimed.

A apparatus 70 for measuring ammonia concentration includes an electromotive force acquisition section 75 configured to acquire information about an electromotive force EMF of a mixed potential cell 55 while a detection electrode 51 is exposed to a target gas, an oxygen concentration acquisition section 76 configured to acquire information about oxygen concentration p.sub.O2 in the target gas, and a control section 72. The control section 72 derives ammonia concentration p.sub.NH3 in the target gas from the acquired information about the electromotive force EMF, the acquired information about the oxygen concentration p.sub.O2, and the relationship represented by formula (1):
EMF= log.sub.a(p.sub.NH3) log.sub.b(p.sub.O2)+B(1)
where , , and B each represent a constant, and a and b each represent any base (provided that a1, a>0, b1, and b>0).

An automated total organic carbon analyzer is described. Embodiments of the system include two features, namely the development of a selective oxidation reactor to oxidize organic contaminants to their corresponding organic acids, and the measurement of the organic acids individually by chain length using an electroanalytical detector. Combining this electroanalytical approach with sequential detection capabilities (such as spectrophotometry) can expand the instrument capabilities by providing organic contaminant speciation. The described reactor performs selective oxidation of organic carbon to organic acids followed by complexation with a proprietary ligand, then selective detection using electroanalytical accumulation and desorption of organic acids performed at an electrode surface.

Provided is a water quality analysis device capable of keeping the device in a clean state without leaving an operation at the time of device power supply activation to an operator and without wasting time and wash water. The water quality analysis device is configured such that: a memory 21 capable of storing a stored content in a cut-off state of the device power supply is provided; the states of the vessels, such as an IC reactor 1 and a TC reactor 2, in which sample water is injected at the time of an analysis operation are sequentially stored in the memory 21; contents of the memory 21 are read at the time of the device power supply activation; and a cleaning operation is automatically executed according to prescribed procedures with the states read for each reactor 1 and 2 as a starting point. Thus, even after the power supply interruption due to, e.g., power outage, the device is kept in a clean state with minimum necessary operations.

Gas analyzer and method for measuring nitrogen oxides in an exhaust gas, wherein to measure the nitrogen oxides, ozone is generated from oxygen, the exhaust gas is treated with the ozone generated to convert nitrogen monoxide within the exhaust gas into nitrogen dioxide, the nitrogen dioxide concentration in the treated exhaust gas is measured photometrically using a first light-emitting diode which emits with a central wavelength between 350 nm and 500 nm and output as the nitrogen oxide concentration in the exhaust gas, and the ozone concentration in the treated exhaust gas is measured photometrically using a second light-emitting diode which emits with a central wavelength between 250 nm and 265 nm, where generation of the ozone using the measured ozone concentration as an actual value is regulated to a prespecified setpoint value to enable reliable continuous measurement of nitrogen oxides in exhaust gases with a low outlay on equipment.

A method in which a concentration of a chemical species of interest is obtained. The method comprises measuring a property (e.g. the oxidation reduction potential) of a reagent (typically based on a simple single electron redox couple) to obtain a baseline measurement. The reagent is mixed with the solution under test, then the property of the mixture is measured to obtain a post reaction measurement. Then the concentration of the chemical species of interest is determined based on the baseline measurement and the first post reaction measurement, typically by calculating a difference of the baseline measurement and the post reaction measurement, then using the difference and a pre-determined conversion table to determine the concentration of the chemical species of interest.

A method for measuring TOC in test water is disclosed. Test water is injected into a combustion tube, which is controlled to be heated in a state of flowing carrier air generated by discharging stored water filled in a combustion gas or carrier air storage tank. After the drying process, temperature in the combustion tube is increased, and the dried organic carbon is burned. Combustion gas is guided to the combustion gas storage tank. An inside of the combustion tube is purified due to high pressure steam generated by injecting pure water and organic carbon removed in the purification process is burned and oxidized. The generated combustion gas is guided to the combustion gas storage tank and is pushed into an infrared meter to measure a carbon dioxide gas concentration. Otherwise, the generated combustion gas is guided to the infrared meter to measure the carbon dioxide gas concentration.

An embodiment provides a method for measuring at least one characteristic of an aqueous sample, including: introducing an aqueous sample into a measurement device comprising one or more electrodes; oxidizing a transition metal to produce a higher valent metal by applying an electrical potential between an anode and a cathode of the measurement device; oxidizing, using the higher valent metal as a catalyst, a material within the aqueous sample; measuring a characteristic of the aqueous sample based upon the oxidized material, using a measurement device selected from the group consisting of: an electrochemical measurement device and an optical measurement device; and optimizing the electrical potential and at least one reagent delivered to the measurement device based on the measurement of the characteristic. Other aspects are described and claimed.

The present invention relates to an analytical device for the elementary analysis, which is improved with regard to the feeding of samples, with a sample holder, a line for oxygen and inert gas, a reactor for catalytic combustion of a sample, a reduction reactor that is provided downstream of the reactor, an adsorber that is provided downstream of the reduction reactor, a detector that is provided downstream of the absorber and a logic unit for processing of the data transmitted by the detector, wherein the sample holder includes a perforated field plate that can be moved by means of a drive on a base that is equipped with an ejection opening to eject one of the samples.

The present invention provides a photolytic converter for converting reactant molecules in a fluid sample into product molecules by photolytic dissociation with electromagnetic radiation. The converter has a reaction chamber in communication with one or more electromagnetic radiation sources, an inflow conduit for conveying the fluid sample into the reaction chamber, and an outflow conduit for conveying the fluid sample out of the reaction chamber into a receptacle, wherein at least one of the first and outflow conduits extends into the reaction chamber. The receptacle can comprise detection means for generating a signal indicative of a concentration of product molecules in the processed fluid sample.