5 results about "Potassium dichromate" patented technology

The application provides a method for detecting the titer of vitamin B12 in a fermentation liquor. The method comprises the following steps: preparing a potassium dichromate solution, a hydrochloric acid solution and a potassium dihydrogen phosphate solution, mixing the three solutions with the vitamin B12 fermentation liquor under certain conditions to generate cyanocobalamin, and then testing the titer of the cyanocobalamin by using a high performance liquid chromatography. The titer of the vitamin B12 detected by using the method is consistent with the titer detected by using a sodium cyanide method. The operation method greatly reduces the safety risk of an analyst caused by using the sodium cyanide, and the operation method is simple, easy to manage in a laboratory and can save the testing cost.

The application discloses a testing method for the content of divalent iron ions in EDTA chemical cleaning solution, and aims at the problem that the existing titration method cannot accurately determine the content of divalent iron ions due to the interference of EDTA. Instead of adopting a complex separation step, the method eliminates the interference through two steps. First, the to-be-tested solution is adjusted to be acidic to weaken the complexing capacity of EDTA, and then a sulfur-phosphorus mixed acid solution is added. The strong acidity of sulfuric acid is used to inhibit the complexing reaction and avoid hindering titration. The whole process is based on the principle of titration method, and does not need expensive instruments and reagents, and is low in cost. The operation is simple and does not need professional skills. The application adopts the high-stability potassium dichromate standard solution, reduces the calibration frequency, realizes rapid, convenient, accurate and low-cost determination, and is suitable for on-site detection requirements.

The present application relates to the technical field of catalyst chemical oxygen demand COD determination, in particular to a COD rapid determination method for improving catalyst system, the chemical oxygen demand COD is a key index for measuring the content of reducing substances in water, after potassium dichromate oxidation treatment, the mass concentration of oxygen corresponding to the amount of potassium dichromate consumed by the oxidized reducing pollutants in the water sample, the determination result directly reflects the degree of water pollution. COD is one of the core parameters of water environment monitoring and treatment, the traditional COD determination method takes potassium dichromate oxidation method as the benchmark, but there are problems such as low reaction efficiency, long time consumption, incomplete oxidation caused by single catalyst, weak anti-interference ability, etc., relying on manual operation, large amount of reagent, high risk of secondary pollution, which is difficult to meet the demand of modern environmental monitoring for rapid, accurate and automatic, for complex water sample, the traditional method is easy to appear determination deviation, the data sharing and remote monitoring ability is insufficient, which restricts the intelligent development of water environment monitoring.

This application relates to the field of environmental monitoring and water quality analysis technology, and in particular to a mixed reagent, test reagent tube, and digestion method for COD detection of petrochemical wastewater. The components, by mass percentage, are: sulfuric acid 75.0–90.0%, potassium dichromate 0.5–1.0%, silver sulfate 1.0–2.7%, scandium sulfate 0.01–0.07‰, potassium hydrogen phthalate 0.1–0.25‰, glucose 0.1–0.25‰, with the remainder being pure water; the mixed reagent does not contain mercuric sulfate. This application enables mercury-free and highly efficient digestion of high-salt, high-organic-content petrochemical wastewater, improves the oxidation efficiency of benzene compounds and polycyclic aromatic hydrocarbons, reduces the detection limit to below 5 mg / L, and the wastewater is easy to treat, combining high accuracy with environmental friendliness.

This application proposes a polishing slurry for ultra-precision optical components in laser equipment and its preparation method, to solve the problem that the chemical corrosion rate and mechanical removal rate of polishing slurries for fused silica are difficult to precisely match, resulting in low processing efficiency or surface corrosion pits. The polishing slurry contains the following components by weight percentage: 5-15% colloidal silica, 5-12% cerium oxide, 2-8% boron carbide, 5-12% silicon carbide, 2-8% iron oxide, 3-10% potassium dichromate, 5-15% citric acid, 2-8% tartaric acid, 1-5% polyvinylpyrrolidone, 0.5-3% ammonium polyacrylate, 0.1%-1.0% surface remodeling agent, 0.5%-2.0% amino acid-based amphoteric surfactant, and 0.01%-0.1% nanodiamond, with the balance being deionized water; the surface remodeling agent is at least one of zirconium fluoride and ammonium fluorozirconate. The resulting component has a surface roughness of less than 0.1 nanometers, achieving atomic-level smoothness without scratches or pitting; subsurface microcracks are filled and repaired by a zirconium oxide layer.