45 results about "ETHYLENEDIAMINE DIHYDROCHLORIDE" patented technology

Methods for determining the concentration of nitrates in several types of water samples by photochemical reduction without the use of toxic materials such as cadmium or hydrazine, and having an approximately 100% reduction efficiency are described. A water sample mixed with a buffered aqueous solution including ammonium salts and EDTA is irradiated using ultraviolet light having wavelengths effective for photochemical conversion of nitrate and nitrite ions (NOx) to detectable species. The resulting species may be quantitatively determined by diazotization using sulfanilamide followed by coupling with N-(1-napthyl)ethylenediamine dihydrochloride which produces a water-soluble azo dye having a magenta color which may be colorimetrically measured at 540 nm from which the nitrate and nitrite concentration in the sample is determined. Nitrite present in the original sample may be colorimetrically analyzed using an unphotolyzed sample and the reaction with sulfanilamide followed by coupling with N-(1-napthyl)ethylenediamine dihydrochloride. When the nitrite concentration is subtracted from the total of the nitrate and nitrite concentration, the sample nitrate may be determined.

The invention provides a method for determining ammonium nitrogen, nitrate nitrogen, nitrite nitrogen and total dissolved nitrogen in a sample, and belongs to the technical field of nitrogen content determination. When the ammonium nitrogen is measured, an oxidizing agent (sodium hypochlorite and sodium chloro isocyanurate) and color developing agent (salicylic acid) system is adopted, the ammonium nitrogen is oxidized into monochloramine under the action of the oxidizing agent, the formed monochloramine and the color developing agent form indophenol, and measurement is carried out by measuring the ultraviolet absorbance at the position of 660 nm; when nitrate nitrogen, nitrite nitrogen and total dissolved nitrogen are measured, a new first Griess reagent (N-(1-naphthyl) ethylenediamine dihydrochloride) and a second Griess reagent system (sulfanilamide and vanadium chloride) are adopted for measurement, the detection limit is low, and the sensitivity is high. The chromogenic reaction is stable and uniform in speed and can be carried out on a 96-well plate.

The invention belongs to the technical field of water quality monitoring, and relates to a method of measuring the ammonia nitrogen concentration of a water body. The method includes a step of preparatory work, a step of mapping an ammonia nitrogen standard curve, a step of mapping nitrite nitrogen standard curve, a step of mapping a curve of influences of nitrite nitrogen concentrations on ammonia nitrogen measurement absolute errors and a step of measuring the ammonia nitrogen concentration, which are five steps. Wider-range ammonia nitrogen and nitrite nitrogen concentrations in a high-salinity water body can be measured. Hypobromite oxidation time is shortened from 30 min to 10 min. Hydrochloric acid is adopted in place of phosphoric acid for a nitrite nitrogen color developing agent, thus reducing pollution. A hydrochloric acid solution of sulfanilamide and an aqueous solution of N-(1-naphthyl)ethylenediamine dihydrochloride are mixed, and therefore nitrite nitrogen concentration measuring steps are simplified. The upper limit of nitrite nitrogen concentration measurement is increased to a value that is three or more times of the upper limit in the national standard method in China. In a nitrite nitrogen concentration range of 0-0.75 mg / L, accuracy of measurement of ammonia nitrogen concentrations in a range of 0-1.25 mg / L is good. The method has characteristics of a simple process, reliable principles, short operation time, environment protection, energy conservation, a low economic cost, high operationality and high measurement result accuracy.