304 results about "Sulphosalicylic acid" patented technology

The invention provides tea polyphenol test paper, which is prepared by using transition metal, such as iron, as a color development agent; using tartaric acid, citric acid, oxalic acid, hydrofluoric acid and salicylsulfonic acid, or any of sylvite, sodium salt and potassium sodium tartrate thereof as a complexing agent; and using soluble starch, polyvinyl alcohol, agaragar, polyacrylamide gel or gelatin as a bonding agent. Meanwhile, a standard tea polyphenol concentration color card is prepared. The tea polyphenol content can be quickly and visually observed according to the contrast between the color development of a sample to be tested on the detecting test paper and the standard color card. The test paper is suitable for quickly measuring the tea polyphenol content in plants or plant products, particularly suitable for the measurement of tea polyphenol content in tea. The test paper has the advantages of simple method, convenience, rapidness, low cost and easy popularization.

The invention discloses a preparation method for nickel-cobalt-manganese ternary hydroxide for a lithium battery. The preparation method comprises the following steps: dissolving nickel salt, cobalt salt and manganese salt in water to prepare water solution, mixing stabilizing agent with the water solution to obtain solution A, adding precipitating agent in the solution A for coprecipitation, and conducting purification and heat setting treatment to the obtained sediment to obtain the nickel-cobalt-manganese ternary hydroxide. The invention has the advantages that the preparation method for the nickel-cobalt-manganese ternary hydroxide is simple, the harmful gases causing environmental pollution are not caused in the process of preparation, the crystal lattices and the unit cells of the prepared nickel-cobalt-manganese ternary hydroxide are tidy, other atoms, ions and molecules are evenly embedded in and out, and thereby the electrochemical properties, the photochemical properties and the structural stability of the corresponding products are improved.

A reagent for measurement of leukocytes and hemoglobin concentration in the blood includes a cationic surfactant in an amount sufficient to lyse erythrocytes and denature hemoglobin, at least one of the following hemoglobin stabilizers:(a) sulfosalicylic acid, or its salt, in an amount effective for promoting the conversion of hemoglobin into methemoglobin,(b) 0.2 to 10.0 g / L of a water-soluble chelating agent having a nitrogen atom and a carboxyl group, and(c) piperazine, or its salt, in an amount effective for promoting the conversion of hemoglobin into methemoglobin, anda buffer for maintaining pH at 4 to 6.

The invention provides a preparation process of doxycycline hydrochloride. In the preparation process, 5-hydroxy-6-demethyl-6-desoxy-6-methylene-11-chlorotetracycline is pressurized and hydrogenated with hydrogen in the presence of catalyst-palladium / carbon (Pd / C) and adjuvant and then reacts with 5-sulfosalicylic acid to obtain alpha-6-doxycycline 5-sulfosalicylate; then alpha-6-doxycycline base is generated after basification; and finally the doxycycline hydrochloride is generated through salt transformation. The preparation process of the doxycycline hydrochloride has the advantages that the productivity and stereoselectivity are improved, the content of related substances in the finished product is reduced, and the high-quality finished product is obtained.

The invention provides a preparation method for nickel, cobalt and aluminum hydroxide. The preparation method comprises the steps that a nickel salt solution and a cobalt salt solution are mixed to obtain a first mixed solution; an aluminum salt solution and a complexing agent are mixed to obtain a second mixed solution; under the action of a precipitant, a coprecipitation reaction is performed on the first mixed solution and the second mixed solution to obtain the nickel, cobalt and aluminum hydroxide, the complexing agent is prepared from aqueous ammonia, ethylene diamine tetraacetic acid and sulfosalicylic acid or glycine, the temperature of the coprecipitation reaction is set at 40 DEG C-65 DEG C, and the pH value of the coprecipitation reaction is set at 10.5-12. By controlling the material adding order, selection of the complexing agent and the temperature and the pH value of the coprecipitation reaction, the prepared nickel, cobalt and aluminum hydroxide has the better spherical appearance and is concentrated in particle size and high in tap density. The invention further provides the nickel, cobalt and aluminum hydroxide prepared through the method and a cathode material for a lithium ion cell.

The invention relates to a method for preparing an electropolymerized sulfosalicylic acid modified glassy carbon electrode, and use of the glassy carbon electrode as a tryptophan electrochemical sensor in high-sensitivity measurement of tryptophan in compound amino acid injection, and belongs to the technical field of electrochemical analysis and detection. The invention mainly aims to prepare the electropolymerized sulfosalicylic acid modified glassy carbon electrode to perform sensitive quantitative analysis and measurement on the tryptophan by a differential pulse voltammetry. Experimental results show that: the modified electrode has an obvious sensitization effect on the tryptophan in a phosphate buffer solution at the concentration of 0.1mol / L and the pH of 3.5, and under the optimal conditions, the differential pulse voltammetry is adopted for measurement, and the tryptophan at the concentration in a range of 5.0*10<-8>-4.0*10<-4> and peak current of the tryptophan have a good linear relation, and the detection limit is 4.0*10<-8>. When the method is used for measuring the tryptophan content in a medicine, results are satisfactory.

The preparation method for conductive polyaniline with doped-composite acid is characterized in that, adding the aniline monomer, dopant, solvent, oxidant, and acidic solution into reactor to mix rapidly and form emulsion; controlling strictly the reaction condition; then, adding demulsifying agent, clearing, filtering, baking, and grinding to solid powder; adjusting the composite proportion between sulfosalicylic acid and type of other assist doped acid to control effectively the conductivity. This product can be used in antistatic material, EM shielding material and electronic element package.

The invention belongs to the technical field of sensors and relates to a preparation method for a dendritic-nanometer-structure polyaniline air-sensitive sensor. The preparation method comprises the steps of preparing polymethyl methacrylate (PMMA) nanometer fiber (namely an insulation high polymer material) by an electrostatic spinning method, immersing the PMMA nanometer fiber serving as a reaction template or a basement into polyaniline reaction solution doped with sulfosalicylic acid, wrapping a layer of conduction polyaniline on the surface of the PMMA nanometer fiber by in-situ polymerization, and forming a dendritic nanometer structure in self assembly on the surface of the polyaniline wrapping layer by controlling reaction time, polymerization temperature, and a reaction condition of molar ratio between an aniline monometer and a doping agent, so as to obtain coaxial-structure polyaniline fiber, wherein the contact area between the coaxial-structure polyaniline fiber and gas to be tested is large. The dendritic-nanometer-structure polyaniline air-sensitive sensor is simple in structure, small in power consumption, simple in preparation method, low in cost, good in mechanical property, and low in possibility of breaking; and as the polyaniline wrapping the outer layer of the coaxial polyaniline fiber has a coral-antenna-shaped dendritic structure, the surface of the sensor, which is in contact with the gas, is enlarger, so that the sensitivity and response speed of the sensor are high.

The invention discloses an application of a Pd catalyst in a hydrogenation process for producing doxycycline, belonging to the field of pharmaceutical chemistry synthesis. The method is as follows: based on polyvinyl chloride-polyethylene polyamine-loaded palladium complex (pvc-pp-Pd) used as a catalyst, and 11 alpha-chlorine-6-methylene oxytetracycline or 11 alpha-chlorine-6,12-hemiketal oxytetracycline or metacycline or salts thereof used as raw material, introducing hydrogen, stirring and reacting, filtering, adding sulfo-group salicylic acid to filtrate so as to form salt; and cooling, filtering, washing and drying so as to obtain alpha-6-deoxytetracycline sulfo-group salicylic acid salt, wherein the yield is higher than 90%, the content of the corresponding beta-6-deoxytetracycline sulfo-group salicylic acid salt isomer is less than 1%. The method has the advantages of mild reaction conditions, good reaction directionality and less side reactions; a toxic agent is not required inthe hydrogenation process, and pollutant emission is reduced, thereby being beneficial to protecting the environment; and the catalyst can be recycled, and production cost is reduced, thereby extremely being beneficial to industrial production.

The invention discloses a chemical polishing method of stainless steel by high-temperature oxidation, and belongs to the field of surface treatment of stainless steel parts. The method comprises the following steps: using phosphoric acid, sulfuric acid and nitric acid as main materials; supplementing additives: polyethylene glycol, sulfosalicylic acid and nicotinic acid which are used to prepare a chemical polishing liquor; introducing an ultrasonic cleaning instrument in the chemical polishing process; and polishing the surface of a stainless steel part within a short time by means of cavitation of ultrasonic wave in the polishing liquor. The chemical polishing method provided by the invention is high in polishing efficiency, less in pollution and strong in operability. Polished parts are bright and white in surface, and uniform and meticulous. The method is especially suitable for polishing treatment of stainless steel parts with precision screws, high precision sizes, deep holes, blind holes, superfine holes and complex structures.

The invention discloses a detection method for trace protein of a Chinese medicinal injection, which is used for detecting the protein impurities of the Chinese medicinal injection so as to control the quality of the Chinese medicinal injection. The detection method is characterized by comprising the following steps of: 1) applying a Chinese medicinal injection sample on a protein specific adsorption film; 2) washing the sample application film with organic solvent-containing solution to wash away the natural color of dots of the Chinese medicinal injection; and 3) subsequently performing coomassie brilliant blue staining on the sample application film. If the protein contained in the Chinese medicinal injection is no less than 12mu g / ml, stable and differentiable blue can be displayed on the film. The detection sensitivity of the method is higher than that of a sulfosalicylic acid precipitation method, and the detection method has high anti-interference capacity and is suitable for the detection of the trace protein of all the Chinese medicinal injections.

The invention relates to measurement of peroxide values, and in particular relates to an edible oil peroxide value measurement combined reagent and a detection method. The edible oil peroxide value measurement combined reagent comprises a polarity organic solvent, a reducing agent, a color development reagent and a color development stabilizing agent, wherein the polarity organic solvent comprises ethanol with the mass concentration of 237-710 g / L in percentage by mass; the reducing agent comprises ferrous sulfate with the mass concentration of 1-20 g / L in percentage by weight; the color development reagent is a sulfosalicylic acid solution with the mass concentration of 300-1,000 g / L; and the color development stabilizing agent is a pyridoxamine dihydrochloride solution with the mass concentration of 20-800 g / L. By a colorimetric analysis method, the operation is quick and simple, and interference caused by heating on a detection result is reduced; the types of the needed detection reagents is few, and the reagents are convenient to combine and carry; and the edible oil peroxide value measurement combined reagent can develop and detect a plurality of oil samples at the same time, is uniform in developing, is low in toxicity and even non-toxic, and is safe and environmentally-friendly.

The invention discloses an alkali-free liquid setting accelerator containing cellulose and a preparation method of the alkali-free liquid setting accelerator. The alkali-free liquid setting accelerator comprises components in parts by mass as follows: 30-60 parts of aluminum sulfate, 5-10 parts of calcium formate, 5-10 parts of calcium fluoride, 0.8-1.6 parts of sulfosalicyclic acid, 1.0-3.5 parts of hydroxyethyl cellulose, 0.8-1.5 parts of polyacrylamide, 0.2-1.0 part of ethylenediamine tetraacetic acid, 1-3 parts of triisopropanolamine, 0.15-1.2 parts of polypropylene glycol, 0.10-1.12 parts of dimethyl silicone, 0.5-1.5 parts of phosphoric acid, 0.5-1.5 parts of hydrofluoric acid, 3-8 parts of magnesium sulfate, 1-3 parts of sodium fluoride, 1-4 parts of trimethylolethane, 2-6 parts of aluminum hydroxide and 30-60 parts of water.

The invention relates to a method for plating zinc and nickel on a neodymium-iron-boron material, and belongs to the field of alloy plating processes. The method comprises the following steps of: (1) firstly carrying out roll finish chamfer treatment on the neodymium-iron-boron material by adopting vibrating type roll finish; (2) placing the neodymium-iron-boron material into a deoiling solution and carrying out ultrasonic deoiling; (3) then carrying out derusting treatment by adopting a nitric acid solution with the volume fraction of 10%; (4) carrying out hole sealing treatment by using a low-temperature particule plugging agent; (5) then carrying out activating treatment under the condition of room temperature by using a sulfosalicylic acid solution; (6) plating the neodymium-iron-boron material subjected to the treatment; (7) carrying out polishing treatment on the plated neodymium-iron-boron material, and then carrying out zinc-nickel alloy plating layer passivating treatment; (8) finally carrying out subsequent impregnation treatment by adopting passivated impregnating resin. The method for plating zinc and nickel on the neodymium-iron-boron material, which is disclosed by the invention, greatly enhances the corrosion-resistant capacity of a neodymium-iron-boron surface after the neodymium-iron-boron surface is treated and reduces the magnetic loss through the improvement of a process and has the advantages of simple process and easiness for popularization and use.

The invention discloses a method for promoting fast germination and enhancing salt tolerance of rice seeds in seashore saline land. The method includes the steps that firstly, an aqueous hydrogen peroxide solution with the mass fraction being 10%-15% is used for soaking the rice seeds for 20-30 minutes; then the rice seeds are soaked by water for 8-10 hours, and then a NaCl aqueous solution of 2-5 mmol / L is used for soaking the rice seeds subjected to water immersion for 15-30 minutes; afterwards, the rice seeds are soaked for 1-2 hours by an aqueous solution including proline of 20-45 mmol / L and sulfosalicylic acid of 0.5-2 mmol / L, and then the rice seeds are soaked for 1-2 hours by an aqueous gibberellin solution of 70-200 mg / L; then the soaked rice seeds are germinated, and the germinated rice seeds are sown in a seashore saline land field. By the adoption of the method, the rice seeds are subjected to long-termed salt stress treatment, and then the mixed solution prepared from the proline and the sulfosalicylic acid and gibberellin are used for soaking the seeds, so that the germination capacity and salt tolerance of the rice seeds are improved quickly, and the bottleneck problem that the emergence rate of direct seeding rice seeds in the seashore saline land is low is solved. The method has great practical application value.

The invention discloses a liquid mass spectrometry method for detecting various amino acids in human blood plasma in an underivatized mode. The method includes the following steps that firstly, the human blood plasma is obtained and subjected to deproteinization with sulfosalicylic acid, and supernate is obtained; secondly, the supernate is mixed with an internal standard solution containing a volatile ionized reagent, LC-MS / MS is used for analysis, wherein according to chromatographic conditions, 1 mM perfluoroheptanoic acid aqueous solution serves as a mobile phase A, a 1 mM perfluoroheptanoic acid acetonitrile solution serves as a mobile phase B, and gradient elution is conducted; according to mass spectrum conditions, multi-ion reaction monitoring of positive ion electrospray ionization is conducted. A volatile ionized reagent sample is added to a sample and mobile phase system, analysis time is short, analysis efficiency is improved, operation is easy, and accuracy of experiment results is improved. LC-MS / MS is used for detecting twenty amino acids in the human blood plasma, specificity, sensitivity and flux are high, operation is easy, sample processing is easy, detection time is short, and the method is particularly suitable for clinical application and popularization.

The invention relates to a method for preparing conductive non-woven fabric by using an in-situ polymerization method, comprising the following steps of: impregnating the non-woven fabric in a solution consisting of pyrrole, anthraquinone-2-sodium sulfonate or anthraquinone-2,7-sulfonic acid sodium salt and water; dropping a solution consisting of ferric nitrate, 5-sulfosalicylic acid and water into the mixed solution in which the non-woven fabric is impregnated; in the presence of the oxidation of the ferric nitrate, subjecting the pyrrole to in-situ polymerization to synthesize polypyrrole;and forming a conductive layer on the surface of the non-woven fabric through adsorption precipitation of the polypyrrole. The preparation method disclosed by the invention has the advantages of simpleness, low cost, no pollution and mild reaction condition and is suitable for large-scale industrial production. The conductive non-woven fabric prepared by using the preparation method has favorableconductivity, electromagnetic shielding performance, flexible characteristics, and the like.

The invention provides a method for extracting lanthanum from coal ash. The method comprises the following steps that 1, coal ash is acidified and dissolved through hydrochloric acid to be prepared into an acidic leaching solution, particularly, the coal ash and the hydrochloric acid are mixed and reacted, then, filtration is carried out, and the acidic leaching solution is obtained; 2, sulfosalicylic acid is added into the acidic leaching solution prepared in the step 1 for a complex reaction, then, an extraction agent is added for extracting and separating the rare earth element in the acidic leaching solution, and hydrochloric acid is added into the extraction phase for reextracting and separating the rare earth element in the extraction phase, and a rare earth mixed solution is obtained; and 3, resin is extracted for separation to obtain a lanthanum solution, particularly, the impregnating resin is prepared, the rare earth mixed solution obtained in the step 2 is used for extracting the resin to separate lanthanum, a leacheate is used for leaching the impregnating resin with lanthanum adsorbed, and a lanthanum solution is obtained. The method for extracting the lanthanum from the coal ash is simple and easy to operate, lanthanum can be extracted from coal ash, and the extraction rate and extraction purity are high.

The invention relates to a ferric ion stabilizing capability measurement method of an acidification ferric ion stabilizer, which comprises the steps that: excess standard ferric ion solution is added into a certain amount of ferric ion stabilizer, so complex reaction is generated between all the ferric ion stabilizer and the standard ferric ion solution, then the pH is adjusted to between 5-6, the redundant Fe<3+> is hydrolyzed to generate the Fe(OH)3 flocculent precipitate, the precipitate is removed through centrifugation, all the supernatant is collected, and in the acid medium, a sulfosalicylic acid spectrophotometric method is utilized to test the total ferric content which is stabilized by the ferric ion stabilizer. The invention has the following advantages that: 1, the adopted method is simple and quick to operate, and has good repeatability and high precision; 2, the problems of multiple repeated heating, repeated diluting, finish determination and the like of the liquid do not exist in the adopted method, and the personal factor is prevented from influencing the test result; and 3, the test precision of the ferric ion content is high, and the test of the ferric ion is benefited.

The invention discloses a cleaning agent for development equipment. The cleaning agent comprises 5-30 parts by weight of a main agent of and 3-15 parts by weight of an auxiliary agent, wherein the main agent consists of one or more of sulfonamic acid, sulfosalicylic acid, citric acid, phosphoric acid and glycollic acid; the auxiliary agent consists of one or more of oxalic acid, ammonium bifluoride, maleic anhydride and polyethylene phosphate. The cleaning agent consisting of the main agent and the auxiliary agent in weight ratio is configured into a cleaning solution to clean the development equipment, so that scales and crystals in the development equipment are effectively removed, meanwhile, the corrosion rate of the cleaning solution to the development equipment is reduced during cleaning, the development equipment is protected, and the service life of the development equipment is prolonged.

The invention discloses tin plating electrolyte. The tin plating electrolyte comprises the following components 60 to 90g / L of tin methane sulfonate, 10 to 30g / L of tin sulfate, 110 to 140mg / L of p-cresolsulphonic acid, 60 to 120mg / L of sulfosalicylic acid, 30 to 50g / L of phosphinic acid, 45 to 70mg / L of 2,2-PySSPy, 15 to 25mg / L of 8-hydroxyquinoline, 20 to 30mg / L of catechins, 10 to 15g / L of 2,2-dihydroxy diethyl sulfide, 5 to 10mg / L of hexadecylpyridinium bromide, 8 to 12 g / L of dodecyl-phenol polyoxyethylene ether, 5 to 10g / L of ethylene glycol, 4 to 8g / L of benzalacetophenone, 5 to 10g / L of sodium hexametaphosphate, 4 to 8g / L of sodium dodecyl sulfate, and the balance of deionized water. According to the tin plating electrolyte, Sn2<+> can be effectively restrained to convert into Sn4 <+> in an electrolytic process by improving an electrolyte formula, and the stability of plating solution is improved; and meanwhile, the throwing power of the electrolyte is increased, and the luminance, the corrosion resistance and the welding performance of tin coatings are improved.

The invention relates to environment-friendly derusting conditioning fluid for metal equipment of a flue-curing barn. By the environment-friendly derusting conditioning fluid, the technical problem of poor derusting effect or high cost and the like in the conventional deruster is solved. According to the key point of the technical scheme, the environment-friendly derusting conditioning fluid is prepared by mixing and stirring the following raw materials in part by weight: 50 to 70 parts of deionized water, 20 to 30 parts of orthophosphoric acid, 1 to 3 parts of zinc hydroxide, 2 to 4 parts of manganous dihydrogen phosphate, 0.5 to 1.5 parts of sodium tripolyphosphate, 1 to 3 parts of sulfosalicylic acid, 1 to 3 parts of sodium nitrite, 2 to 4 parts of boric acid, 0.5 to 1.5 parts of sodium molybdate and 0.5 to 1.5 parts of polyvinyl alcohol. By the environment-friendly derusting conditioning fluid, rust melting and rust proofing are completed at one time, so that the labor production efficiency is improved greatly, and the cost of conditioning rust is reduced. The environment-friendly derusting conditioning fluid can be widely applied to a surface treatment process for steel devices.

The invention relates to a method for preparing dehydrolinalyl acetate from dehydrolinalool. The method comprises esterification between dehydrolinalool and acetic anhydride is carried out in the presence of catalyst so as to obtain dehydrolinalyl acetate. Molar ratio of raw material provided of dehydrolinalool to acetic anhydride is 1: (1-5); reaction temperature is 25-70 DEG C; reaction pressure is normal pressure; reaction time is 20-150min; the catalyst is sulfosalicylic acid, dosage of which is 0.05-5wt percentage of total amount of the raw material provided. Compared with the prior art, the invention has the advantages that reaction activity of the adopted esterification catalyst is high, which is reflected by moderate reaction temperature and short reaction time, raw material conversion and product selectivity, etc. are ideal and removal of the catalyst from the product is convenient.

The invention discloses an etching solution composition for a copper layer and a titanium layer and a method of preparing an array substrate for a liquid crystal display using the same. The etching solution composition comprises persulphate and sulfosalicylic acid, so that the multiple metallic layers including copper layers and titanium layers can be uniformly etched in at a high speed in an environmental-friendly way. Excellent thermal control performance and time stability are ensured.

The invention discloses a rapid analysis method of biogenic amine in fish. The common biogenic amine (nine types of biogenic amine comprising agmatine, histamine, tyramine, spermine, spermidine, 2-phenylethylamine, tryptamine, cadaverine and putrescine) is analyzed in a targeted manner by taking 5-sulfosalicylic acid as an extraction solvent, adopting bead agitating and grinding as an extraction method, taking benzoyl chloride as a derivatization reagent and adopting an LC (liquid chromatogram)-triple tandem quadrupole mass spectrometry. The biogenic amine is detected in a multi-reactions monitoring manner by taking ion pairs with optimum response, which are obtained by optimization, as quantitative ion pairs and taking ion pairs with following response as auxiliary qualitative ion pairs.According to the method, the sample extraction time and the biogenic amine derivation time can be greatly shortened, so that the analysis time of the whole analysis process is greatly shortened. The analysis method has the advantages of being simple in sample pretreatment, rapid in derivation, high in detection sensitivity, high in repeatability and the like.

The invention relates to clear fracturing fluid, which is used for fracturing treatment of a hypotonic and water-sensitive reservoir, and comprises the following components in percentage by weight: 0.5-5 percent of dimethyl octadecyl ethoxy quaternary ammonium nitrate; 0.2-2 percent of sulfosalicylic acid triethanolamine ester; 0.5-2 percent of potassium chloride; and the balance of water, wherein the weight percentage of the components is a hundred percent. A preparation method comprises the following steps of: adding clear water into a mixing liquid tank, adding the potassium chloride and the sulfosalicylic acid triethanolamine ester under a stirring condition, uniformly stirring, adding the dimethyl octadecyl ethoxy quaternary ammonium nitrate, and stirring for 15 minutes after adding the materials, so that the concentration or the viscosity of liquid in the upper part and the lower part of the tank is uniform. The clear fracturing fluid has the effects that: the clear fracturing fluid is suitable for fracturing the reservoir at the temperature of 10 DEG C-110 DEG C, the damage caused by residues of the fracturing liquid and reservoir water sensitivity can be reduced, and the crude output is improved.

The invention relates to desulfurizing agents for gaseous phase esulfurization, and discloses a composite chelated iron desulfurizing agent and a preparation method thereof. High valent soluble ferricsalt is added into deionized water to be kept stirred, atype A chelating agent and a type B chelating agent are sequentially added and to be kept stirred, a pH buffer agent is gradually added till the solid matters are completely dissolved, the pH buffer agent is added continuously till the pH value is adjusted to 8.0-13.5, and the mixed matters are continuously stirred and react for 4-8 hours, so that the composite chelated iron desulfurizing agent is obtained; the type A chelating agent is one or more of HEDTA, EGTA, DGA, 2-peracetic acid malonic acid, 2-peracetic acid isobutyric acid and sodium salt and potassium salt thereof, the type B chelating agent is one or more of sodium citrate, sulfosalicylic acid, sodium sulfosalicylate dihydrate, sodium gluconate, mannitol and oligose, the mole ratio of the type A chelating agent to the type B chelating agent is from (1:1)to (1:0.25), the mole ratio of the chelating agents to high valent water-soluble ferric salt is from (1:1)to (3:1), and the mass percentage of Fe in the desulfurizing agent is 1.0-6.0wt%. The composite chelated iron desulfurizing agent is high in saturated sulfur capacity and stability, and wide in pH application range.

The invention discloses a measurement method for a permanganate index. The method comprises the following steps: (1) adding a to-be-measured water sample into a colorimetric tube provided with a plug, adding (1+10) sulfuric acid for acidification, adding a potassium permanganate solution, and shaking uniformly; (2) digesting the water sample in the step (1) under a certain condition and quickly cooling to a room temperature; (3) adding an excessive ammonium ferrous sulfate solution into a digestion solution in the step (2), and shaking uniformly; (4) adding a proper amount of a sulfosalicylic acid aqueous solution into a reaction solution in the step (3) for producing a color development reaction; (5) performing absorbance testing on the water sample in the step (4) by taking de-ionized water as a reference at the wavelength of 510 nm, and calculating the permanganate index of the water sample by a formula IMn=-8.5*(A-A0), wherein in the formula, IMn is the permanganate index of the water sample, A is the absorbance of the water sample, and A0 is the absorbance of a blank solution. The measurement method is quick and accurate in detection, suitable for batch measurement and simple to operate, and can be widely applied to laboratory detection and outdoor emergency detection.