51 results about "Diphenylcarbazide" patented technology

The invention provides a test strip for detecting heavy metal-chromium (Cr) in water quality and a preparation method thereof, and belongs to the technical field of water quality detection. The test strip sequentially comprises an insulating waterproof substrate, a reaction substrate membrane, a filter layer and a cover plate which are bonded together from the bottom up, wherein, two distance sleeves are respectively arranged at the sides of the test strip. The operating method comprises the following steps: immobilizing a color-developing agent (diphenylcarbazide) into the test strip; placing the obtained test strip in a photoelectric sensor, and then dropping a Cr-containing sample solution into the test strip for full color development reaction; and utilizing the sensor to irradiate the test strip by virtue of monochromatic light, then collecting green reflected light and finally converting the green reflected light into an electrical signal. The reflectivity of the developed test strip and corresponding Cr concentration show good linear relation after color development, the detection limit is less than 5mol / L, and the test time is less than 3 minutes. Repetitive experimental data proves that the method has the advantages of good repeatability and short detection time; and by utilizing the method, on-site rapid reagent-instrument integrated detection of Cr ions can be realized.

The invention discloses a reagent for determining hexavalent chromium by spectrophotometry, which is characterized in that the reagent is prepared from concentrated sulfuric acid, water, absolute ethyl alcohol and diphenylcarbazide based on the weight ratio of 10-20:20-50:60-90:0.05-0.5. The invention also discloses a method for preparing the reagent for determining the hexavalent chromium by spectrophotometry, comprising the steps of dissolving the concentrated sulfuric acid in a little of water, adding the absolute ethyl alcohol and diphenylcarbazide, evenly shaking and dissolving, and adding the balance of water. The invention has the advantages of convenient use and good environment-friendly performance.

The invention relates to a multi-passage direction selecting flow-injection quick analysis system for hexavalent chromium water quality. A photoelectric flow cell, a reaction tube, an injection pump, an indicator storage bottle and a carrier fluid storage bottle are connected with a multi-passage direction selecting valve through a capillary pipeline; a valve cover of the multi-passage direction selecting valve is provided with a direction selecting connector which can be communicated with one of connectors of an upper valve seat through the rotation of the valve cover; the direction selecting connector of the valve cover is connected with the injection pump through a capillary storage pipe; the connectors of the valve seat are connected with the reaction tube, a water sample source, two guide samples, the indicator bottle and the carrier fluid bottle respectively; and the photoelectric flow cell is connected with an outlet of the reaction tube. The system makes the quantitative water sample and the diphenylcarbazide indicator continuously flow along with the carrier fluid in a continuous flow-injection mode; the water sample and the indicator diffuse in the carrier fluid and react to generate red fluid; and the content of hexavalent chromium in the water sample is measured through the photoelectric flow cell. The system has the advantages of simple structure, convenient operation and quick measurement, and is applicable to on-line real-time monitoring of the hexavalent chromium water quality.

A method for detecting sexavalence Cr in dyed leather product includes using phosphate buffer liquid to extract sexavalence Cr in dyed leather product, carrying out discoloring on extracted liquid by graphitized carbon black solid phase extraction column being modified by chemical dressing agent, reacting discolored-extracted liquid with diplenyl carbazide under acidic condition then utilizing ultraviolet-visual spectrphotometric analysis to determine content of sexavalence Cr in dyed leather product.

The invention specifically relates to a method for rapid detection of hexavalent chromium ions in sewage, which belongs to the field of detection of metal ions. The method comprises the following steps: adding 100 ml of distilled water or deionized water into a wash bottle; sequentially adding 1 ml of 1+1 sulfuric acid and 1 ml of 1+1 phosphoric acid and shaking up an obtained mixture; adding 4 ml of a prepared diphenylcarbazide solution and shaking up an obtained mixture; adding 100 ml of distilled water or deionized water and shaking up an obtained mixture for usage in subsequent detection; taking 2 to 5 ml of a water sample to be detected, adding 2 to 5 ml of a hexavalent chromium ion detection reagent with a wash bottle, shaking up an obtained mixture, observing the color of mixed liquor and determining the range of the content of chromium ions in detection liquid by observing whether the mixed liquor has a color or by observing the color which the mixed liquor displays. Application of the method provided in the invention for detection of hexavalent chromium ions enables detection time to be saved and on-site detection to be realizable; the method has the advantages of simpleness, easy operation and strong practicality.

The invention relates to a determination method of metal chromium, and particularly a detection method of hexavalent chromium content. According to the method, a sample is decomposed by an acid, and a mauve complex is generated by allowing hexavalent chromium Cr6+ to react with diphenylcarbazide under an acidic condition; colorimetric determination is performed to obtain the chromium content. The method of the invention has simple operation, good reproducibility, and high accuracy.

A method of preparing an aqueous composition of a chromium III compound, comprising adding hydrogen peroxide to a mixture comprising water and a chromium VI compound in the presence of at least one acid according to the formula H2GF6, in which G is a Group IV-B element. The composition may contain less than 500 ppm of alkali metal ions and less than 200 ppm of halide ions, relative to chromium and may test negative for chromium VI using s-diphenylcarbazide. The composition may be used for treating a metal surface, among other applications.

The invention relates to a monitoring method for total chromium and discloses a method for automatic online monitoring of total chromium in water. The method comprises the following steps: firstly, sampling: firstly, pumping 5ml of sample liquid into a chromoscope of an instrument through a liquid pump; secondly, adding a reagent: respectively pumping 0.5ml of sulfuric acid and 0.5ml of phosphoric acid with the volume ratio being 1:1 respectively into the chromoscope of the instrument; then adding 2.5ml of oxidant and 0.2 percent potassium permanganate; heating a mixed solution at the temperature of 100DEG C for 10 minutes; and then cooling the mixed liquid to room temperature; thirdly, developing: adding 5ml diphenylcarbazide as a developing agent for developing reaction and setting the developing time as 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes and 30 minutes respectively; and fourthly, analyzing: accumulating the results of the third step, averaging and storing the result into the instrument or transmitting the result to a server. The method disclosed by the invention has the advantage of accurately measuring the total chromium in a water sample by using an online monitor.

The invention relates to a method for rapidly detecting the total concentration of chromium in water. The method comprises the following steps that water to be detected is sampled, and the pH value of the water sample to be detected is detected through a pH test strip and is adjusted; 5 ml of the water sample to be detected is placed in a prefabricated tube containing 2 ml of potassium persulfate solution in advance, and 0.2 ml of copper sulfate solution is added to the water sample to be detected; a heating digester is switched on, the temperature is set to be 165 DEG C, after the temperature reaches 165 DEG C, the prefabricated tube containing the mixed water sample is inserted into a heating digestion groove, the prefabricated tube is sealed, and then digestion lasts for 10 minutes; after digestion, the prefabricated tube is taken out and cooled to the indoor temperature, 0.05 ml of phosphoric acid solution is added, and 0.2 ml of diphenylcarbazide color-developing solution is added after even mixing; after the mixed solution stands for 10 minutes, the prefabricated tube containing the mixed solution is inserted into a colorimetric groove of a photometer, a blank is used as a contrast, and colorimetric analysis is conducted at the position with the distance of 540 nm; the absorbance of the water sample to be detected is substituted into a total chromium concentration standard curve and is multiplied by dilution ratio, and then the total concentration of chromium is obtained. According to the method for rapidly detecting the total concentration of chromium in water, the detection speed is high, and the application quantity of a poisonous agent is small. The invention further provides a detection kit which is convenient to carry and use and is used for the method for rapidly detecting the total concentration of chromium in water.

The invention discloses a method for detecting total chromium in water. The method comprises the following steps: putting five chromium standard solutions that the volumes are the same and the concentrations are respectively 0 mg / L, 0.05 mg / L, 0.1 mg / L, 0.5 mg / L and 1 mg / L into five reactors, adding 0.03-5% of dilute sulfuric acid, and adjusting the pH values to be 1-3; respectively adding 1-3ml of 0.3-3% diphenylcarbazide alcoholic solution, and uniformly stirring; respectively adding 1-3ml of 1.5-5% hydrogen peroxide solution, respectively adding 0.5-4.2% sodium hydroxide solutions, adjusting the pH values to be 11-13, uniformly stirring, and standing for 1 minute; respectively adding 4.8-44% of sulfuric acid, adjusting the pH value to be 0.1-2, uniformly stirring, and standing for 1 minute; respectively transferring the obtained solutions into cuvettes, and measuring the absorbancy under a light source of 540nm one by one; making a standard working curve according to the measured ABS values of the five standard solutions; taking one water sample, repeating the steps 1-6, and substituting a measured ABS value of the water sample into the standard working curve to calculate the concentration of the total chromium in the water sample. The method can save time and labor, and can simply and accurately detect total chromium in water.

The invention discloses a method for detecting the content of hexavalent chromium ions in a passivating solution. The method comprises the following steps: 1, accurately measuring a passivating solution sample, adding a complexing agent and a buffer solution to the sample, and carrying out a stirring reaction for 10-30min; 2, introducing a solution obtained after the reaction to a separating funnel, adding an organic solvent to extract, separating a water phase and an organic phase, and collecting the obtained water phase; 3, adding an acid solution to the water phase in order to adjust the pH value of the water phase to 1.5-2.5; 4, adding an acetone solution of diphenylcarbazide, carrying out color development, and adding a solvent to a constant volume; and 5, determining the absorbance of a sample obtained in step 4 by using an ultraviolet and visible spectrophotometer at 540nm, and calculating the content of Cr<6+> in the sample. The method adopting a 5-Br-PADAP complexing agent and a sodium carbonate-sodium bicarbonate buffer solution with the pH value of 9 to separate out various interference ions and remove interference colors, so the content of the hexavalent chromium ions can be accurately determined.

The invention relates to a method for testing metal chromium, in particular to a method for detecting the chromium content of organic chromium. The method comprises the following steps of: decomposing a test sample by using acid, oxidizing all Cr3<+> of the sample into Cr6<+> by using ammonium persulfate under a silver nitrate water catalytic condition, and reacting the Cr6<+> with diphenylcar bazide to generate an amaranthine complex compound under an acidic condition; and performing colorimetric estimation to obtain the chromium content. The method is simple in operation, high in reproducibility and high in accuracy.

The invention provides a method for testing water-soluble hexavalent chromium in cement or clinker. Through performing washing and vacuum filtering on a cement and clinker sample containing water-soluble hexavalent chromium, removing quantitative filtrate and adding a diphenylcarbazide solution, adjusting acidity by using (1+1) hydrochloric acid, coloring, measuring the absorbance of a solution ata wavelength of 540 nm, and measuring the concentration of chromium (VI) in the solution through standard curve method, so that the content of hexavalent chromium in the sample is obtained. Comparedwith the prior art, the method for testing water-soluble hexavalent chromium in cement or clinker provided by the invention simplifies the test operation steps and sample processing steps; and the operating steps, and the concentration and amount of the substance are unified in the construction process of the standard curve and the sample, which is conducive to improve the accuracy, repeatabilityand reproducibility of the test.

The invention provides a hexavalent chromium color developing agent and a preparation method of the hexavalent chromium color developing agent. The hexavalent chromium color developing agent comprises a chromium indicator, and an esters organic solvent for prolonging the shelf life of the hexavalent chromium color developing agent. According to the hexavalent chromium color developing agent, diphenylcarbazide is dissolved in solvent containing the esters organic solvent, so that the shelf life of the color developing agent is prolonged and is up to more than three months; phthalate anhydride and other slightly-soluble quality-guaranteeing agents are not required in the color developing agent, and the allocation efficiency of the color developing agent is improved; and besides, the color developing agent also can improve the coverage rate of a sample to the light rays of a light source in a hexavalent chromium detection process, even if the content of the hexavalent chromium in the sample is low, the hexavalent chromium can be detected, and the detection sensitivity can be improved.

The invention relates to a method for treating hexavalent chromium-containing wastewater by photocatalytic reduction of a nickel oxide-nickel cobaltate-black titanium dioxide compound. The method comprises the following steps: preparing black titanium dioxide, dissolving cobalt nitrate hexahydrate, nickel nitrate hexahydrate and the black titanium dioxide in a proper amount of deionized water, magnetically stirring to form a uniform solution, adding a proper amount of polyvinylpyrrolidone (PVP, K30) into the solution, and stirring the suspension with a magnetic stirrer for at least 1 hour; dispersing urea into the suspension, grinding powder, and calcining the powder in a tubular furnace in air at 500 DEG C for 2 hours to obtain the nickel oxide-nickel cobaltate-black titanium dioxide compound; adding the nickel oxide-nickel cobaltate-black titanium dioxide compound into the hexavalent chromium-containing wastewater; taking out the mixture at a certain time interval, immediately filtering, measuring the concentration of the treated hexavalent chromium at 540nm by using an ultraviolet-visible spectrophotometer according to a 1, 5-diphenylcarbazide method, and calculating the removalrate. The method has the advantages of high removal rate, low treatment cost, environmental friendliness and the like.

The invention relates to a preparation method and a use method for color development detecting tablets for determining hexavalent chromium in water. The color development detecting tablets are prepared by mixing diphenylcarbazide, sulfamic acid and polyethylene glycol 4000 and are prepared into tablets by a tabletting method. The color development detecting tablets are directly soaked into 10ml of water sample when used, the solution is gently shaken for 10 minutes to dissolve the color development detecting tablets, and a portable spectrophotometer is used for measuring to acquire the concentration of the hexavalent chromium in the water. The color development detecting tablets are convenient to carry and easy to preserve; any additional reagents are not required when the color development detecting tablets are used; the determination results are accurate and reliable; and the color development detecting tablets are suitable for on-site quantitative detection of the hexavalent chromium in water bodies, such as surface water, underground water, domestic sewage, industrial wastewater and the like.

The invention discloses a method for rapidly detecting the content of chromium in furniture factory wastewater. The method comprises the following steps: selecting acetone, sulfuric acid, phosphoric acid, a 20% urea solution, a 4% potassium permanganate solution, a 2% sodium nitrite solution and a 0.2% sodium hydroxide solution for later use, weighing zinc sulfate, and dissolving the zinc sulfate in water; weighing sodium hydroxide, dissolving the sodium hydroxide in water, and mixing the obtained zinc sulfate solution with the obtained sodium hydroxide solution; weighing dry potassium dichromate, dissolving the dry potassium dichromate in water, transferring the obtained solution to a 1000 mL volumetric flask, and allowing the content of hexavalent chromium in the obtained storage solution to be 0.100 [mu]g / mL; sucking 5.00 mL of the chromium standard storage solution to a 500 mL volumetric flask, and allowing the content of hexavalent chromium in the obtained standard use solution to be 1.00 [mu]g / mL; weighing 0.2 g of diphenylcarbazide, dissolving the diphenylcarbazide in 50 mL of acetone, adding water to dilute to 100 mL, reducing Cr<6+> into Cr<3+>, adjusting the pH value of a water sample to 8, adding a color developer solution, disposing the obtained water sample for 5 min, carrying out acidifying color developing, and making a standard curve by using the above same method; and calculating a result. The method has the advantages of simple detection process, high accuracy of the detection result, avoiding of damages of standard exceeding chromium to human bodies, and protection of people's health.

The invention discloses an on-site emergency detection reagent for chromium in water and a use method thereof. Chromium (VI) and diphenylcarbazide (DPC) have chromogenic reaction under acidic conditions to prepare a color developing agent, ceric sulfate and chromium oxide (III) have oxidation reaction under acidic conditions to prepare oxidant, and sodium azide is selected as a reduction agent. The use method includes the following steps that firstly, when the concentration of chromium (VI) in a water sample is measured, a color developing agent I is added into a 5 mL to-be-detected water sample and dissolved till the volume is 10 mL, the mixture stands still for 10 min and is measured by a portable spectrophotometer, and the concentration of chromium (VI) in the to-be-detected water sample is obtained; secondly, when the total chromium concentration in the water sample is measured, the oxidant A is added into a 5 mL to-be-detected water sample, the water sample is light yellow, the mixture stands still for 10-15 min, then 1-2 drops of reduction agent B is added till light yellow fades, a color developing agent II is added till the volume is 10 mL, the mixture stands still for 10 min and is measured by the spectrophotometer, and the total chromium concentration in the to-be-detected water sample is obtained. The reagent has the advantages of being high in sensitivity, good in accuracy, high in timeliness, convenient to carry and the like.

The invention discloses a method for detecting the concentration of a chromium ion in a water body. The method comprises the following steps: (1) preparing a buffer liquid; (2) preparing a color developing agent; and (3) drawing a standard liquid curve, adding 0.5mL of a phosphoric acid solution and 1mL of diphenylcarbazide solution again to develop, finally adding water to the scale, stewing for 15 minutes, taking the to-be-determined water body, and determining at the wavelength of 540nm. According to the method for detecting the concentration of the chromium ion in the water body is simple in equipment instrument, is high in precision and accuracy, and is suitable for the water body detection.

The invention provides a chromium measurement reagent, which can sufficiently inhibit decline of sensitivity along with time, and simultaneously provides a chromium measurement reagent with high intitial sensitivity. The chromium measurement reagent contains solvent and the solvent contains diphenylcarbazide and hydroxylamine hydrochloride. One chromium measurement method is used for reaction of the sample liquid and the chromium measurement reagent under acid condition, thereby measuring the absorbance.

The invention provides a powder indicator for quickly determining cement hexavalent chromium content. The powder indicator is characterized in that the powder indicator is prepared from the followingcomponents in parts by weight ratio: 65-70 parts of hexavalent chromium color developing agent diphenylcarbazide copolymerization modified polymer, 0.15-1.0 part of quality assurance agent vitamin C,0.15-2.0 parts of cosolvent acetamide, 25-30 parts of acidity regulator sodium bicarbonate, and 0.15-1.0 part of stabilizer ethylenediamine tetraacetic acid disodium salt. The powder indicator is powdery solid, and does not contain organic solvent and water, the stability of the indicator is improved, and the effective storage time is prolonged; the powder indicator can be stably stored for 1-2 years normally under a sealing light-avoiding condition. The powder indicator can be quickly dissolved in the water, and the defect that the color developing agent diphenylcarbazide is low in solubilityin water and easy to oxidize and degenerate in organic solvent or water is overcome. The indicator provided by the invention can be directly added in the to-be-tested sample solution, the detection is quick and sensitivity, the experiment time is saved, the determination index completely conforms to the national standard, and has extensive popularization and application value.

The invention discloses a method for detecting chromium ions in water. The method comprises the following steps: mixing diphenylcarbazide, sodium chloride, ammonium citrate, ethylenediamine disodium tetraacetate, glycine, N,N-dimethyl-p-phenylenediamine and sodium xylene sulfonate, grinding so as to obtain a detection reagent A; preparing a 1+7 sulfuric acid solution so as to obtain a detection reagent B; and taking the detection reagent A, adding the detection reagent B and a water sample in sequence, mixing, standing for 5min, performing absorbancy detection at wave length being 540nm, and calculating the content of the chromium ions. The method disclosed by the invention is easy and fast to operate, and meets the green chemistry idea, the use amounts of reagent are small, and an organic solvent acetone is avoided.

The invention discloses a chromium detection polymer film and its preparation method and use, and belongs to the technical field of analysis. The chromium detection polymer film is characterized in that a layer of nano-particles are coated on the surface of a polymer film as a matrix by photografting; a mixture of dodecyltrimethylammonium bromide, polyvinyl alcohol and citric acid is loaded on the nano-particles; and diphenylcarbazide (DPC) as a color-developing agent is loaded on the mixture. The preparation method comprises the following steps that a layer of the nano-particles are coated on the surface of the polymer film as a matrix by photografting; and after pretreatment, the DPC as a color-developing agent is loaded on the nano-particles. In use, a standard solution and the chromium detection polymer film undergo a reaction so that standard color gradation is obtained; and after a reaction of a solution needing to be detected and the chromium detection polymer film, a color is compared with the standard color gradation so that a detection result is obtained. The chromium detection polymer film has high detection precision and good repeatability, can be operated easily, realizes fast on-site detection of chromium ions in an environmental water sample, avoids use of a traditional large-scale instrument in chromium detection, and has a low cost and a good application prospect.

The present invention discloses a stable polypropylene composite material for household electric appliances. The stable polypropylene composite material comprises the following raw materials by weight: 0.4-1 part of diphenylcarbazide, 1-2 parts of elm bark powder, 2-4 parts of iso-octyl methacrylate, 3-5 parts of polyvinylidene fluoride, 1-2 parts of naphthenic oil, 2-4 parts of dry carbide slag, 4-7 parts of stakactite powder, 10-12 parts of gibbsite powder, 0.1-0.3 part of di-n-octyltin bis(isooctyl thioglycolate), 2-4 parts of vinyl carboxylic ester, 0.6-1 part of polyvinyl pyrrolidone, 1-3 parts of polytetrafluoroethylene fibers, 90-97 parts of polypropylene, and 3-4 parts of a modification auxiliary agent. The stable polypropylene composite material of the present invention has characteristics of good dimensional stability, good weather resistance, good surface resistance, good hot-water-resistance, and strong protection property, and is especially adopted as the household electric appliance exterior parts such as the refrigerator top cover, the air conditioner base, the foot bath device and the like.

The invention discloses a water-quality hexavalent-chromium mixed color developing agent and a preparation method thereof. The mixed color developing agent per 100mL comprises, by weight, 0.2g of diphenylcarbazide, 70mL of ethyl alcohol, 6-12mL strong phosphoric acid and 18-24mL of water. According to the color developing agent, the ethyl alcohol replaces acetone, serves as solvents and is environmentally friendly and harmless to human body, and the environments cannot be polluted. When the color developing agent is used, 2mL of mixed color developing agents are directly added, so that hexavalent chromium can be measured, the strong phosphoric acid is added into the mixed color developing agent, acidity is controlled, and the influence of ferric iron in a water sample on measurement of hexavalent-chromium content can be removed. The mixed color developing agent simplifies measuring steps and is high in measuring accuracy.

The invention belongs to the field of rapid hexavalent chromium detection and particularly relates to a hexavalent chromium detection indicator fluid as well as a preparation method and a use method thereof. The hexavalent chromium detection indicator fluid comprises diphenylcarbazide, a solvent, a pH adjusting agent and a diluting agent; the solvent is one of or a mixture of two of any percent mass ratio of dimethylacetamide and dimethylformamide. The hexavalent chromium detection indicator fluid provided by the invention effectively solves the technical problems of tedious current dibenzoyl diglyhydrazine preparation process, low dissolution efficiency and the like; meanwhile, the concentration of diphenylcarbazide in the hexavalent chromium detection indicator fluid is improved, and the shelf life of the hexavalent chromium detection indicator fluid is prolonged.

The invention discloses a detection kit which is used for on-site quick detection of chromium ions in water and capable of eliminating reagent blank influences and a preparing method of the kit. In a faintly acid medium, hexavalent chromium in water reacts with diphenylcarbazide to generate a purple red complex, and the shade of the purple red complex is in direct proportion to the concentration of chromium ions; a comparison with a test tube is made after the color of a chromium ion standard color chart with reagent blank eliminated and a blank tube color are overlaid, and the concentration of chromium ions in a water sample to be tested is obtained. The detection kit is especially suitable for on-site quick detection of chromium ions in water.