102 results about "Bromothymol blue" patented technology

The invention relates to a food freshness indicator card taking indicated CO2 as a characteristic gas and a manufacturing method of the food freshness indicator card. The manufacturing method comprises the following steps: firstly, crushing a polylactic acid sample, dissolving by chloroform, after heating in water bath, laying on a clean glass grinding tool through a tape-casting process, and drying to prepare a basal membrane; and dissolving bromothymol blue powder and methyl red powder in an ethanol solution, after stirring, uniformly mixing with polyethylene glycol and methylcellulose powder, laying on the basal membrane, drying to obtain the indicator card, independently packing the indicator card, and adding a drying agent into the indicator card for controlling the humidity surrounding the indicator card and improving the accuracy of discoloring generated after CO2 is absorbed by the indicator card. According to the manufacturing method, a self-made polylactic acid membrane is used as the indicator card basal membrane and is smooth in surface, uniform in texture and bright and translucent in appearance, and thus vision errors are furthest reduced. Due to invention and application of the freshness indicator card, consumers can purchase healthy and high-quality foods, and Chinese food safety is greatly improved.

The invention relates to the field of food detection, and relates to a preparation method of intelligent indicator labels for freshness of meat, and application, and the preparation method comprises the following steps of firstly preparing a fluorescent carbon quantum dot, dissolving the fluorescent carbon quantum dot in ethanol with bromothymol blue, and adjusting the pH value to obtain a freshness indicator; mixing the chitosan solution, polyvinyl alcohol solution and freshness indicator, forming an indicator film after being de-foamed and dried by ultrasound, and wrapping with a low densitypolyethylene film to obtain intelligent freshness indicator labels; recording the visible light color pictures of the labels for different storage days after coexisting the labels with the meat to form a visible light colorimetric card, and recording the fluorescent color pictures to form a fluorescent color colorimetric card; and when the colors of the labels change after the meat to be tested and the labels coexist, realizing the visual detection of the freshness of the meat through the color comparison of the colorimetric cards. The labels prepared by the invention are safe and environmentally friendly, and the fluorescent nano-materials combined with the traditional color indicators make the color signals of the indicators more abundant and the measurement results more accurate.

The invention provides a method for distinguishing variety of fritillaria and detecting total alkaloid content of the fritillaria by virtue of near infrared spectrum. The method provided by the invention comprises the following steps: (1) collecting a fritillaria sample; (2) measuring the near infrared diffuse reflection spectrogram of the fritillaria sample, preprocessing the 4000-5000cm<-1> wave band in the spectrogram, and performing cluster analysis on the pre-processed near infrared spectrogram to build a qualitative model; or preprocessing the 4000-7000cm<-1> wave band in the spectrogram, so as to obtain an absorbance, associating the absorbance with the alkaloid content of the sample measured by virtue of bromothymol blue colorimetry, and building a quantitative correction model for detecting alkaloid by one or more methods of a partial least squares method, a principal component regression method and a multiple linear regression method; (3) collecting the near infrared spectrogram of the sample to be measured, after the corresponding preprocessing is performed, distinguishing the variety of the fritillaria and detecting total alkaloid content of the fritillaria by utilizing the built qualitative model or quantitative correction model. The method provided by the invention has the characteristics of fast speed, no damage, environment friendliness and low cost.

The invention relates to a piece of highly sensitive pH test paper and a preparation method thereof, wherein a developing strip is in the form of a piece of pH body paper, which is dipped in a reagent solution and then dried by hot air at constant temperature; the reagent solution contains an indicator; the formula of the indicator contains bromothymol blue, thymol blue, metanil yellow, m-methyl red, bromocresol green, nitrazine yellow, cresol red, phenolphthalein, para-nitrophenylazosalicylate sodium, titan yellow, fluorescent pigment orange red, 5% 4-nitrobenzenediazo-1-naphthol-3.6-sodium disulfonate solution and 30% dissolved ethanol aqueous solution; and the formula of the indicator further contains an aqueous colour fixing agent, a cotton wooden fibre mildew preventive, a special paper mildew preventive and a buffer neutralizer formed by modulating sodium hydroxide and phosphoric acid. The preparation method comprises the following steps of: adjusting the reagent solution till a pH value is up to 6-7.5, uniformly wetting the pH body paper, and drying through hot air at constant temperature. According to the invention, the reagent solution can be adjusted, so that the pH value is up to 6-7.5; steady and precise high sensitivity of the pH1-14 test paper is effectively increased; and the test paper is convenient and simple to use.

The invention provides a humidity indicator which is really effective in environmental protection and comprises a carrier and solution used for soaking the carrier; wherein, the solution takes 30-80% of ethanol as a solvent and contains 0.00862-0.00992% of acid-base indicator and 0.8-13.8% of hygroscopic salt. The acid-base indicator is one of bromocresol green, bromothymol blue, thymol blue, thymolphthalein, bromophenol blue, methyl red, methyl orange, methyl yellow , neutral red and phenol red or the mixture thereof. The hygroscopic salt is alkali halide or alkali-earth metal halide. The humidity indicator of the invention has wide indicating range (capable of indicating 5-90% of ambient humidity) and high sensitivity. Diverse humidity indicators different in discoloration can be manufactured by adjusting the components. The humidity indicator of the invention has evident discoloration effect, simple use, reutilization, good suitability and extensive application.

The invention provides a mixed indicator. The indicator component of the mixed indicator provided by the invention is basically composed of bromothymol blue, methyl red and phenolphthalein. Detection of grease acid value with the mixed indicator provided by the invention has the characteristics of: convenience and speediness, and high stability detection result. Distinguishing can be realized easily only by visual inspection; operation can be carried out of a laboratory, and the detection process requires only a small amount of organic solvents, thus facilitating detection of a large number of samples. The mixed indicator can be used for dark color grease detection.

The invention provides a culture medium used for separating and screening lactic acid bacteria. The formula of the culture medium comprises the following components: relative to the dosage of 1000ml of a solvent, 5.0-15.0g of tryptone, 5.0-15.0g of beef extract, 2.0-10.0g of yeast extract, 1.0-3.0g of diammonium citrate, 15.0-25.0g of glucose, 0.2-2.0 mL of Tween-80, 2.0-8.0g of sodium acetate, 15.0-20.0g of agar, 2.0-30.0g of calcium carbonate, a compound acid-base indicator containing 0.01-0.5g of methyl red and 0.01-0.7g of bromothymol blue, 0.5-5.0g of ascorbic acid, 0.1-0.5g of L-cysteine HCl, and a selective antibiotic composed of 250000-500000 IU of polymyxin B and 0.01-0.05g of nalidixic acid, wherein the pH value of the culture medium is 6.8; and the solvent is composed of a primary solvent and a secondary solvent, the primary solvent is distilled water or aged seawater, and the secondary solvent is saline solution. The culture medium has the characteristics of being high in accuracy, obvious in authentication phenomenon and the like during separation and screening for lactic acid bacteria.

The invention discloses a quick determination method for PH value of a textile. Prior determination method has too many working procedures, and wastes time, and hurts the textile because of using a PH determination device. Extreme inconvenience is existent in production application, which is not benefit for quickly monitoring. The invention has flowing the steps that: filter paper is set under the textile which is to be determined, and extraction liquid is dropped in the textile surface, then force application is affected to the position of dropping the extraction liquid, and the extraction liquid permeates into the filter paper through the textile, afterwards, a mixed indicator is dropped on the position of dropping the extraction liquid, after color development, PH value is quickly determined through color in the filter paper, the mixed indicator includes phenothalin indicator, bromothymol blue indicator, methyl red indicator and thymol phenothalin indicator. The invention can determine the textile PH value which changes from 3.0 to 11.0 by application of complementary color in the mixed indicator under the condition of different acidity-basicity of indicator, therefore, the quick, simple, high accuracy determination for the textile PH value is achieved.

The invention relates to a method for determining content of silicon and zirconium in silicozirconium alloy, and belongs to the technical field of material chemical analysis. The method comprises the following steps: decomposing a sample with nitric acid and hydrofluoric acid to convert the silicon into fluosilicic acid; adding potassium fluoride to generate potassium fluosilicate precipitation; filtering, washing and adding hot water to decompose the potassium fluosilicate precipitation to release hydrofluoric acid; using bromothymol blue or phenolphthalein as indicator to carry out titration with a sodium hydroxide standard solution until the solution turns to blue or light red as an end point; calculating the content of silicon; dissolving the sample with nitric acid and hydrofluoric acid, carrying out perchloric acid smoking, reacting zirconium with mandelic acid in a hot hydrochloric acid medium to generate an insoluble mandelic acid white precipitation; calcining the precipitation at 850-900 DEG C; weighing in the form of oxide; and conducting conversion to obtain the content of zirconium. The method for determining silicon and zirconium content in silicozirconium alloy has not been reported so far, and the method provided by the invention solves the problem, has the advanategs of simpleness, fastness, high accuracy and good repeatability, and is favorable for popularization and application.

The invention relates to a method for testing the content of boron trioxide in glass containing zinc and lead, belonging to the technical field of chemical analysis testing. The method comprises the following steps: dissolving a sample by using a conventional glass treatment method (alkali fusion method) to convert boron into borates, dissolving the fused mass in dilute acid, adding carbonates, and separating the borates from other impurity elements; and complexing the amphoteric elements (zinc and lead) by using Ca-EDTA (Ethylene Diamine Tetraacetic Acid); and adding mannitol to quantitively convert boric acid into alcohol boric acid with strong degree of dissociation, and accurately controlling the titration end-point by using a mixed indicator of bromothymol blue and phenol red. The testing method has the advantage of clear discolored points, is easy to control, and can effectively eliminate the interference of amphoteric elements (zinc, lead and the like) in the glass, thereby obviously enhancing the measurement accuracy and repetitiveness. The relative standard deviation of the test is reduced to below 0.5%, and the standard recovery rate is higher than 98%.

A method for the in vivo detection of urease-producing helicobacter in the upper stomach is disclosed. The dense carrier is divided into two separate groups which are combined with separate reagent indicators, one of which also contains urea. The carriers are food soluble products, preferably sugar beads having a diameter of approximately 0.2 to 3.0 mm. The treated carriers and urea are encapsulated in a soluble capsule which is administered to a patient. The density of the carriers cause the capsule to migrate to the gastric mucosa, where the capsule, but not the reagents, is dissolved, placing the reagents and urea in direct contact with the gastric mucosa. The urea reacts with any urease present in the stomach by creating ammonia, which increases the pH in the immediate vicinity of the urea containing carrier and indicator beads. The two reagents react differently, through color change, to the increase in pH, which is viewed through use of an endoscope. A preferred first reagent is bromothymol blue (dibromothymolsulfonphthalein), which changes yellow in the presence of urease, and a preferred second reagent is phenol red (phenolsulfonphthalein), which turns red in the presence of urease.

The invention discloses a pancreatic juice developer, and a preparation method and an application thereof. The pancreatic juice developer comprises 0.03-0.70g/L of bromothymol blue sodium salt, 0.03-0.70g/L of phenol red sodium salt and 1.23-11.76g/L of sodium bisulfate monobydrate. Compared with pancreatic juice developers in the prior art, the pancreatic juice developer has the advantages of high chromogenic sensitivity and obvious color contrast in the intraoperative seepage detection process. The pancreatic juice developer can flexibly realize pancreatic juice visualization in the intraoperative and postoperative processes according to concrete demands by preparing different dosage forms and selecting carriers in order to accurately realize qualitative diagnosis and intraoperative positioning diagnosis of pancreatic fistula.

The invention relates to ratio fluorescent nano hydrogel for pH value sensing and a preparation method thereof, belonging to the field of pH value sensing materials. The method comprises the following steps of: weighing polyurethane, bromothymol blue, coumarin 6 and Nile red according to a mass percent of 1:0.05:0.05:0.005; adding the weighed polyurethane to a mixed solution of alcohol and water with a volume ratio that the alcohol to the water is 9:1 to prepare a solution with a concentration of 500ppm; dissolving the bromothymol blue, the coumarin 6 and the Nile red together in the obtained solution and stirring for 1h; dialyzing for 24h in secondary distilled water and changing water every 4h to obtain a hydrogel suspension; and filtering the prepared suspension to obtain a product. The invention overcomes the defect that the detection sensitivity with single fluorescence intensity can be weakened because of the distribution and the concentration of probes and the random drift of an optoelectronic system and is suitable to be used as a pH value detection material in cells.

The invention discloses a reagent freeze-dried microsphere for detecting concentrated carbon dioxide binding force and a preparation method of the reagent freeze-dried microsphere. The reagent freeze-dried microsphere comprises a buffer solution, carbonic anhydrase, phenol red, bromothymol blue, a preservative, trehalose, polyethylene glycol, TrionX-100 and the like. The preparation process of the reagent freeze-dried microsphere mainly comprises the following steps: (1) preparing a solution, filtering and degassing; (2) preparing microdroplets by using an accurate quantifying liquid separation system, and dropping the microdroplets into liquid nitrogen to prepare frozen spheres; and (3) transferring the frozen spheres to a freeze dryer to freeze and dry, thereby obtaining the freeze-dried reagent microsphere. A reagent for detecting carbon dioxide binding force disclosed by the invention is a spherical particle freeze-dried reagent, and can be pre-packaged into a detection chip. Compared with an existing liquid detection reagent, the reagent has the advantages that stable preservation and transportation at room temperature can be achieved; and compared with a freeze-dried powder reagent, the reagent has the advantages of being accurate to quantify, convenient to package and the like, and can be suitable for a POCT biochemical analyzer introducing a microfluidic chip technology.

The invention provides a children toy, in particular to a colorful-changeable flour-mud powder, according to mass percentages, which contains thymol phthalein of 0.05-0.06 accounts, fenolftaleina of 0.039-0.047 accounts, cresol red of 0.024-0.034 accounts, bromothymol blue of 0.015-0.025 accounts, anhydrous sodium carbonate of 2.95-3.35 accounts, citrate of 3.14-3.67 accounts and flour of 92.59-94.39 accounts. The preparation method comprises weighting and mixing indicator and anhydrous sodium carbonate uniformly, baking at 100DEG C for 20-30min, screening via 80-200 meshes, weighting and mixing citrate and flour uniformly, adding the screened power, packing, and obtaining the colorful-changeable flour-mud powder. The product can be added with water to be kneaded into mud form, with color change in kneading process. The invention has special formula, simple preparation and no hurt on human body, which color change function can develop children intelligence and develop practical ability.

The invention relates to the technical field of medical treatment, in particular to a pancreatic leakage detection material based on acid-base indication compound chemical color changes and application thereof. The pancreatic leakage detection material is a water absorption material comprising a solution loaded with acid-base indication compounds, and is prepared by preparing a solution through acid-base indication compounds and dropwise adding the solution to the water absorption material. The acid-base indication compounds are thymol blue or a mixture of thymol blue and bromothymol blue. By means of the pancreatic leakage detection material, tissue liquid with pancreatic juice and tissue liquid without pancreatic juice can be distinguished through obvious color changes under the condition of low-dosage pancreatic juice, and the high detection flexibility and the large detection range are achieved.

The invention discloses a selectivity differential medium-vibrio alginolyticus selectivity differential medium (VaDM) which uses rapid screened vibrio alginolyticus as a unique target bacterium. The vibrio alginolyticus selectivity differential medium is prepared from leucine, yeast leaching powder, sodium chloride, sodium thiosulfate, sodium cholate, bile powder, ferric citrate, calcium chloride, agar, bromothymol blue, thymol blue and distilled water. In the invention, all components of the VaDM are optimized and combined according to a special leucine aminoase system of vibrio alginolyticus, basic and special nutrition requirement, halophilism and resistance on some bacteriostats, favorable growth of the bacterium is guaranteed, the growth of a plurality of other miscellaneous bacteriacan be effectively inhibited, the target bacterium presents special bacterial colony color and achieves good selecting and distinguishing effects with other bacteria. The invention verifies that VaDMhas an ideal effect on the rapid screening of vibrio alginolyticus by testing bacterium yield, accuracy, precision and sensitivity and comparing the conventional detecting method for detecting a practical sample.

The invention discloses a method for measuring content of silicon dioxide in iron ores, relates to a detecting method and in particular relates to the method for measuring content of silicon dioxide in iron ores. The method comprises the following steps of: decomposing the silicon dioxide iron ore samples at certain temperature by adopting hydrofluoric acid-nitric acid; controlling the volume of the test solution to form a ternary constant-boiling system of fluosilicic acid, hydrofluoric acid and water; adding potassium chloride and potassium fluoride in hydrochloric acid-nitric acid mixture medium, so that silicic acid is precipitated out in the form of potassium fluosilicate large crystals; removing free acid by filtering and washing the precipitates, generating hydrofluoric acid by hydrolysis adopting boiling water, and using bromothymol blue-phenol red as an indictor and using sodium hydroxide standard titration solution to titrate so as to obtain the content of the silicon dioxide in the iron cores. The method has the characteristics of being simple, quick, low in cost, good in reproducibility and the like.

Provided is a test system, a test method and a test kit based on a test medium comprising Bromothymol Blue or a structurally related indicator.

The invention discloses a preparation method of an indicating material for detecting the freshness of foods via carbon dioxide. The preparation method comprises the following steps: 8-15 percent by mass of gelatin is added in 85-92 percent by mass of deionized water to be swelled to obtain a membrane solution A; 4-8 percent by mass of starch, 0.05-0.2 percent by mass of calcium hydroxide, 0.5-4 percent by mass of glycerol and the balance of deionized water are mixed to prepare a membrane solution B; 2-6 percent by mass of polyvinyl alcohol is added in 94-98 percent by mass of deionized water to prepare a membrane solution C; a methyl red solution with the concentration of 0.05%-0.2% and a bromothymol blue solution with the concentration of 0.05%-0.2% are prepared and mixed at the volume ratio of 1:(1.5-2.5) to obtain an indicator; after the membrane solution A, the membrane solution B and the membrane solution C are blended according to the volume ratio of 1:(1-2):(0.1-0.5), 3-8 percent by mass of indicator is added to prepare the indicating material. The pH indicator is combined with the base material, and CO2 gas can be detected accurately and instantly. The invention further comprises the indicating material for detecting the freshness of foods through carbon dioxide.

The invention discloses a salmonella culture medium that contains crystal violet and a production process of the culture medium. The culture medium is prepared from the following raw materials by weight: 5-15 parts of peptone, 5-15 parts of lactose, 0.1-1 part of L-cysteine, 1-9 parts of beef powders, 1-9 parts of sodium chloride, 1-9 parts of sodium citrate, 5-15 parts of cholate, 1-9 parts of sodium thiosulfate, 0.001-0.01 parts of crystal violet, 0.5-1.5 parts of ferric ammonium citrate, 0.050-0.070 parts of bromothymol blue and 11-18 parts of agar. According to the invention, the operation is simple and convenient, the necessary types of culture media for detection can be reduced, the detection time is shortened from 4-7d in a method in prior art to 2d, and the detection sensitivity is high.

The invention discloses a vibrio mimicus chromogenic culture medium with the following formula: 5g of yeast extract powder, 5g of fish peptone, 5g of peptone, 10g of sodium chloride, 8g to 10g of sodium citrate, 8.5g to 11g of sodium thiosulfate, 1g to 5g of sodium cholate, 2g to 7g of ox-bile powder, 15g to 20g of sucrose, 15g to 20g of cellobiose, 15g to 20g of arabinose, 1g to 3g of ironic citrate, 12g to 20g of agar, 0.04g of bromothymol blue, 0.04g of thymol blue and 1000mL of distilled water. The invention designs the vibrio mimicus chromogenic culture medium which is obviously different from other bacteria, especially other vibrio or other food pathogenic bacteria, according to the basic nutritional need, the specific ecological environment, the specific biochemical reaction, namely, an enzyme system and the metabolization rule, and the toleration to specific bacteria-resistant substances and the like of the vibrio mimicus, overcomes the defects of poor selectivity and the like of the traditional culture medium, and can quickly detect the vibrio mimicus in marine food products.

The invention discloses a detection method for trace free acid in an electrolyte lithium salt. The detection method comprises the following steps: (1) weighing a certain amount of de-ionized water and adding a bromothymol blue indicator, and titrating by using a digital titrating device until the solution is blue green based on 0.005-0.1mol/l sodium hydroxide as a titrating agent; and (2) weighing a certain amount of the lithium salt and adding the lithium salt into the de-ionized water titrated by the step (1), agitating and dissolving, standing for 0-1 minute, titrating by using the digital titrating device until the solution is blue green based on 0.005-0.1mol/l sodium hydroxide as the titrating agent, and calculating the content of the free acid of the lithium salt by the consumed volume of the sodium hydroxide. According to the detection method, the temperature of the used de-ionized water is 0-4 DEG C, one part of the lithium salt can be effectively prevented from being decomposed and HF is prevented from being volatilized; the detection accuracy of a sample is improved. According to the detection method, the free acid of the lithium salt is determined by using the electronic titrating device; the detection method has the characteristics of short analyzing time, high precision and the like, and is simple to operate.

The invention relates to test paper for detecting the residual chlorine, pH value and total alkalinity in water. The test paper comprises a substrate and coloration test paper pieces bonded to one end of the substrate; the three coloration test paper pieces comprise a residual chlorine coloration test paper piece, a pH value of coloration test paper piece and a total alkalinity coloration test piece; adjacent pieces have a 1-3 cm distance; the chlorine coloration test paper piece is impregnated with a absolute ethyl alcohol solution of benzophenone thiosulfate with concentration of 0.1-1.9 g/L; the pH value coloration test paper piece is impregnated by a pH value coloration mixed solution containing phenol red and bromothymol blue with concentration ranged from 0.01 to 1 g / L an water-alcohol of surfactant with concentration of 0.1-10 g / L and; and the total alkalinity coloration test paper piece is impregnated with a total alkalinity coloration mixed solution containing water-alcohol of phenol red or bromothymol blue with concentration of 0.1-5 g / L. The test paper provided by the invention has the advantages of rapidness, simpleness, high sensitivity simultaneous detection of residual chlorine, pH value and total alkalinity in water.