39 results about "Paper chromatography" patented technology

The invention provides a sample preparation method for mass spectrometry, aiming to solve the problems of non-ideal detection sensitivity and poor resistance to interference in the field of environmental mass spectrometry. The method comprises the following steps of placing a mixed solution of a sample or specimen and a solvent on chromatography paper, wherein the chromatography paper has an end portion with the width shrunk gradually; performing paper chromatography operation, placing the chromatography paper in a developing solvent to make the sample move toward the end portion of the chromatography paper along with the developing solvent and enrich at the end portion of the chromatography paper; and placing the end portion of the chromatography paper at a detection point of a desorption ionization ion source in a mass spectrometer so as to be desorbed and ionized.

The invention discloses a method for determining the concentration of phosphite by cyclic voltammetry, which comprises the steps of: establishing a working curve by determining the quantitative proportional relation between the oxide peak current intensity of phosphite on a bare Pt electrode and the concentration of phosphite and fitting the working curve as a linear formula, and substituting theoxide peak value of a sample to be detected in the formula to obtain the concentration of phosphite. The method of the invention is accurate in detection results, has the advantages of being simple in experimental conditions, simple and convenient in operation and saving time compared with the traditional methods for determining the concentration of phosphite, such as an oxidation reduction titration method, a paper chromatography, a thin-layer chromatography and an ion exchange chromatography, and has tremendous popularization and application prospect in paint, electroplating and other fields.

The invention relates to a method for screening 1-deoxidation-D-xylulose5-phosphoric acid reduction isomerization enzyme (DXR) inhibitor from plant extract. In the method, paper chromatography, thin layer chromatography or reversal phase ion pairing HPLC method are employed to detect decline of substrate transformation quantity to evaluate inhibiting effect of the plant extract on DXR. In addition, as far as developing solvents employed in the process of paper chromatography are concerned, ethanol with a concentration of 95%: 1M ammonium acetate: 1M EDTA is 70:29:1(v / v / v), colour-developing agent is ethylenediamine sulfate water solution, in the developing system employed in the process of thin layer chromatography, chloroform: methanol is 3:1 (v / v), the colour-developing agent is sulfuric acid ethanol solution; in the reversal phase ion pairing HPLC method, the double phase solution gradient elution method is employed for detection. In the process of screening inhibiting agent in the method, the substrate 1-deoxidation-D-xylulose5-phosphoric acid and coenzyme NADPH do not contain isotope labeling. In addition, the screening process features simpleness, speediness, good feasibility and no detection by expensive large instruments.

A method for detecting diethylstilbestrol belongs to the field of analytical chemistry, wherein the method includes the followings: pre-treating the sample to be detected, preparing the sample solution and then carrying out the following treatments: adding sample solution at one end point of the paper chromatography strip; placing the paper chromatography strip in the normal hexane-ethanol developing solvent; taking out the paper chromatography strip when the front end of the developing solvent is adjacent to the front end of the paper chromatography strip; air-drying, wherein the normal hexane-ethanol developing solvent by volume includes: 1 to 20 parts of normal hexane, 0.1 to 5 parts of ethanol; spraying the potassium ferricyanide-ferric trichloride-H2O2 on the chromatography strip; color displaying, wherein the potassium ferricyanide-ferric trichloride-H2O2 is as follows: mixing the 0.01 to 5 mol / L aqueous solution of the potassium ferricyanide and the 0.01 to 5 mol / L aqueous solution of ferric trichloride evenly; then adding 0.001% to 5% of the H2O2 by volume 1 to 1; and the volume of the H2O2 is 0 to 10% of the total volume of the solution. The invention has the advantages of simple method and device, fast detecting speed and low detecting cost, and can be used for fastly detecting the DES in food on the spot.

The invention provides an identification method for true and fake cubilose, which is characterized in that samples are prepared into a solution to carry out paper chromatography experiment; chromatographic solution with the volume ratio of 5:1:1:1 of normal butanol, pyridines, ethanol (95%) and water is selected and 0.5% of ninhydrin acetone solution is used for colouring; the cubilose sample solution presents purple punctum and the Rf value thereof is 0.57 by the detection; while the hogskin and agaragar of the fake cubilose has no display; therefore, the cubilose can be identified. The identification method for the true and fake cubilose is simple, convenient, quick and exact, and has little charges and extremely good practical values.

The measurement of gossypol in cotton seed products using conventional methods namely spectrophotmetric, NMR methods, chemiluminsecent method, gas-liquid chromatography polarography, thin layer chromatography and paper chromatography are tedious, time-consuming, high cost and needs calibrated systems. In the present invention, a low cost and portable system is devised and the concentration of total gossypol is directly displayed on LCD in mgl−1 or ppm from the test solution and no standard solution is required to make calibration curve for measuring the absorbance.

The invention relates to a simple determination method of 90Sr content in an 89Sr sample. The method comprises the following steps of: taking D2EHPA (di(2-ethyl hexyl)phosphoric acid) / methylbenzene solution as an extracting agent, and HNO3 solution as a developing agent; separating the 89Sr sample by a paper chromatography, and then determining accurate content of the 90Y and 90Sr by measuring the half-life period of an origin paper segment, so as to determine the 90Sr content in the 89Sr sample, wherein the 90Y is a decay daughter of 90Sr. Compared with the prior art, the simple determination method has the advantages of being simple, convenient, economical, effective and the like.

The invention discloses a method for screening lactic acid bacteria producing gamma-amino butyric acid, belonging to the biotechnical field. The method comprises the following steps: taking the separated and purified lactic acid bacteria; inoculating in an MRS culture medium; centrifuging and collecting thallus when the thallus growth reaches the stationary phase; carrying out whole-cell catalysis; taking L-glutamic acid or L-sodium glutamate as a unique substrate; taking acetic acid-sodium acetate as a buffer system; stirring and reacting for 1-24 hours at the temperature of 20-80 DEG C and with the pH of 3.2-8.0; utilizing glutamate decarboxylase producing GAD lactic acid bacteria to lead the L-glutamic acid or the L-sodium glutamate to play decarboxylization, so as to generate the gamma-aminobutyric acid; analyzing whether the reaction system contains gamma-amino butyric acid or not through paper chromatography to screen the lactic acid bacteria producing the gamma-amino butyric acid; and identifying the strains producing the gamma-amino butyric acid by the morphological characteristics, physiological biochemical characteristics and a 16SrDNA sequence. The method of the invention can greatly improve the directional screening efficiency of the functional probiotic bacteria.

The invention discloses a method for detecting artificially synthesized pigments in carbonated beverages. The method comprises the following steps: (1) performing sample treatment; (2) adsorbing and removing impurities; (3) desorbing; (4) concentrating; (5) performing qualitative paper chromatography; and (6) performing quantitative paper chromatography. The method the method for detecting artificially synthesized pigments in carbonated beverages provided by the invention has the beneficial effects that the detection mode is simple, the effect is obvious and the method can be suitable for multiple artificially synthesized pigments. Compared with a conventional chromatographic detection method, the method provided by the invention has higher detection degree.

In an embodiment, a method to detect analytes, the method including contacting a sample on a substrate, where the substrate is a nanoplasmonic paper, performing surface-enhanced Raman scattering detection with paper chromatography separation on the substrate, and identifying at least one analyte in the sample. In a further embodiment, an apparatus to detect analytes, the apparatus including a vacuum pump coupled to a filtration unit operable to collect solid particles off an object and the filtration unit including a filter substrate, where the filter substrate includes nanoplasmonic paper.

The invention discloses a Bacillus sp. to generate non-induced exocytotic chitosanase, which is characterized by the following: detecting enzyme activity of supernatant fermented by strain at 65 deg. c with pH value at 6. 0; displaying the final product as dichitosan and trichitosan through paper chromatography and mass spectrography.

The invention provides a screening method of a D-arabitol high-yield yeast mutant strain. By using a mutant strain obtained by carrying out mutagenesis on Kluyveromyces lactis by a low-energy N+ ion implantation technique as a screening object, a high-flux screening method, which is implemented by primary screening based on a high-sugar solid culture medium and secondary screening based on paper chromatography / high-performance liquid chromatography combination, is established. The method has the advantages of high screening efficiency, low cost, short screening period and the like, is easy to operate, and provides a new method for efficiently screening the D-arabitol high-yield strain by modifying the yeast with low-energy ion implantation.

The invention discloses a mutagenesis method and screening method of lactic acid bacteria with high gamma-aminobutyric acid yield, which comprises the following steps: selecting Pediococcus lactis ZY-6 (Weissellaviridescens ZY-6) as the starting strain, after activation culture, preparation of bacterial suspension, mutagenesis, culture to obtain mutagenic bacteria, and then fermentation culture ofmutagenic bacteria, gamma-Aminobutyric Acid Producing Strain Primary Screening, High Yield gamma-Screening of Aminobutyric Acid Lactic Acid Bacteria for gamma-GABA-producing strains. The method of the invention is simple and easy to operate, low in cost, high and stable in GABA production of mutant strain, and is an effective method for lactic acid bacteria to obtain high-efficient GABA production. The strain is preserved for a long time and has wide application prospect, and the reaction condition is mild. Glutamic acid or L-Sodium glutamate was used as the sole substrate, and no other medium was found in the transformation solution. Using the glutamate decarboxylase of lactic acid bacteria, L-Glutamic acid or L-Conversion of Sodium Glutamate to gamma-Aminobutyric acid, by paper chromatography analysis of the presence of GABA in the conversion solution, to improve the screening efficiency.

The invention belongs to the technical field of food analysis, and more specifically provides a simultaneous detection method of plurality of dopants in milk powder. According to the simultaneous detection method of plurality of dopants in milk powder, a raman spectrometer is used, and the dopants comprise melamine, dicyandiamide, and sodium sulfocyanate. The simultaneous detection method comprises steps of preparation of chitosan-SERS paper chromatography, pretreatment of milk powder samples, separation of paper chromatography, and SERS detection. A preparation method of self-made SERS paper chromatography is simple; cost is low; separation effect is excellent; the raman spectrometer is convenient to carry; the simultaneous detection method is suitable for on-site rapid detection; the pretreatment process of the milk powder samples is simple, and only filtering is needed; an obtained non-blank spectrogram is compared with the standard raman spectrograms of the above three dopants point by point so as to determine whether a detected sample contains the dopants; no reference experiment is needed; the toxicity of a selected developing solvent is relatively low; the developing solvent is friendly to the environment; separation of the dopants is impossible to realize with other developing solvents; separation detection time of the samples is shorter than 25min; and on-site rapid detection can be realized.

A high-throughput screening method for an L-aspartate beta-decarboxylase producing strain is disclosed. The method includes 1) subjecting microorganisms in a sample to enrichment culture and primary separation by adopting an enrichment culture medium, 2) inoculating single colonies obtained through separation from a plane plate to a 96-micropore plate primary screening semisolid medium and performing primary screening to obtain L-aspartate beta-decarboxylase producing strains, 3) inoculating the strains obtained through primary screening to a 24-prore plate, performing liquid culturing, and performing secondary screening to obtain the L-aspartate beta-decarboxylase producing strain with high yield by combining paper chromatography, and 4) subjecting the high-yield strain obtained through secondary screening to fermentation in a shake flask, and determining enzyme activity by combining an oxidation coloration process. The method is suitable for high-throughput screening of the L-aspartate beta-decarboxylase producing strain. The strain obtained through screening is alkali-resistant, thus avoiding tedious pH value controlling steps in a cell production processes. References are provided for high-throughput screening of producing strains bio-enzymes of the same kind.

The invention relates to a pigment paper chromatography separation method, in particular to a chloroplast pigment paper chromatography separation method. The method includes the steps that first, pigment extract is prepared and stored in a place kept out of sun for use; then, cylindrical filter paper is made; finally, sample application is performed, after sample application pigment is dried through an electric hair drier, a small hole is made in the center of the sample application pigment, one end of the cylindrical filter paper is inserted in the small hole, the other end, namely a base end, of the cylindrical filter paper is placed in a culture dish with layer unfolding agent, the round filter paper subjected to the sample application is placed on the culture dish, and chromatography starts. After four colored ribbons (beta-carotene, lutein, chlorophyll a and chlorophyll b) are all separated, the chromatography is completed. According to the method, while the chromatography separation effect, for instance, the color of the colored ribbons is pure and the edges of the colored ribbons are clear, is improved, investment of a chromatography container is reduced and saved by 60 percent, tedious processing of the chromatography filter paper is reduced, and toxic pollution generated when acetone serves as the extraction agent, and the carbon tetrachloride serves as the layer unfolding agent is reduced. The separation method is good in separation effect, time and labor are saved, and environmental pollution and toxicity are reduced.

The invention discloses a synchronous analysis device, preparation method and application of bisphenol A and halogenated derivatives thereof. The device comprises a paper substrate and a composite material modified on the surface of the paper substrate, the composite material comprises a photocatalytic metal organic framework and a molecularly imprinted polymer, and the molecularly imprinted polymer can adsorb bisphenol A and / or halogenated derivatives thereof. According to the analysis device, bisphenol A and halogenated derivatives thereof are synchronously detected with high sensitivity bytaking 2, 7dichlorofluorescein acetoacetic acid as an active oxygen fluorescent probe by utilizing the recognition of a molecularly imprinted polymer, the separation of paper chromatography and the photocatalytic performance of a metal organic framework. The analysis device prepared by the invention can realize multi-component synchronous analysis, has the advantages of low cost, convenience in use, portability, high sensitivity and the like, and can be used for monitoring bisphenol A and halogenated derivatives thereof in samples with complex environments.

The invention belongs to the technical field of food analysis, and more specifically provides a simultaneous detection method of plurality of dopants in milk powder. According to the simultaneous detection method of plurality of dopants in milk powder, a raman spectrometer is used, and the dopants comprise melamine, dicyandiamide, and sodium sulfocyanate. The simultaneous detection method comprises steps of preparation of chitosan-SERS paper chromatography, pretreatment of milk powder samples, separation of paper chromatography, and SERS detection. A preparation method of self-made SERS paper chromatography is simple; cost is low; separation effect is excellent; the raman spectrometer is convenient to carry; the simultaneous detection method is suitable for on-site rapid detection; the pretreatment process of the milk powder samples is simple, and only filtering is needed; an obtained non-blank spectrogram is compared with the standard raman spectrograms of the above three dopants point by point so as to determine whether a detected sample contains the dopants; no reference experiment is needed; the toxicity of a selected developing solvent is relatively low; the developing solvent is friendly to the environment; separation of the dopants is impossible to realize with other developing solvents; separation detection time of the samples is shorter than 25min; and on-site rapid detection can be realized.

The invention discloses a method for identifying male and female trees based on paper chromatography, comprising the following steps of: (1) protein extraction; (2) spotting; (3) chromatography: using20%-30% ethanol solution as anti-male chromatography solution; (4) staining; and (5) male and female identification. The method is simple, reliable in a result, low in the identification cost, and convenient for popularization and application.

The invention discloses a screening method for strains of lactobacilli generating GABA in chickpea milk. Steps of the screening method are as follows: firstly, pretreatment of chickpea milk samples; secondly, separation of amino acids by means of paper chromatography; thirdly, initial judgment of the lactobacilli generating the GABA; fourthly, secondary judgment of the lactobacilli generating theGABA; fifthly, morphological identification of the lactobacilli generating the GABA; sixthly, physiological and biochemical testing for the lactobacilli generating GABA; and seventhly, identificationof the strains of lactobacilli generating the GABA through a 16SrDNA sequence. According to the screening method, researchers divide No. 2 solutions into two parts in the process of detecting the No.2 mixed solutions through a high performance liquid chromatograph, firstly detect one part of the solutions and record data, and then detect the other part of mixed solutions again after the mixed solutions are statically placed for 20-24 hours and record data to compare the data of the two detections, quantity of the GABA in the solutions after static placement is significantly increased, so asto determine the existence of the strains of lactobacilli generating the GABA in the chickpea milk. Therefore, experimental errors are reduced, and the screening method lays a foundation for developing GABA-rich functional food.

A high-throughput screening method for an L-aspartate beta-decarboxylase producing strain is disclosed. The method includes 1) subjecting microorganisms in a sample to enrichment culture and primary separation by adopting an enrichment culture medium, 2) inoculating single colonies obtained through separation from a plane plate to a 96-micropore plate primary screening semisolid medium and performing primary screening to obtain L-aspartate beta-decarboxylase producing strains, 3) inoculating the strains obtained through primary screening to a 24-prore plate, performing liquid culturing, and performing secondary screening to obtain the L-aspartate beta-decarboxylase producing strain with high yield by combining paper chromatography, and 4) subjecting the high-yield strain obtained through secondary screening to fermentation in a shake flask, and determining enzyme activity by combining an oxidation coloration process. The method is suitable for high-throughput screening of the L-aspartate beta-decarboxylase producing strain. The strain obtained through screening is alkali-resistant, thus avoiding tedious pH value controlling steps in a cell production processes. References are provided for high-throughput screening of producing strains bio-enzymes of the same kind.

The invention belongs to the technical field of extraction and purification of plant rare monosaccharides, and discloses a method for preparing plant pure 2-octulose in small quantities. The recovery plant craterostigma plantagineum normally growing is used as a material, is extracted by a methanol solution and is steamed to dry under reduced pressure, a precipitate is re-dissolved, then impurities such as pigments, proteins, salt ions and amino acids are removed by chloroform washing, ion exchange resin adsorption and other steps, and a carbohydrate mixture is obtained. The carbohydrate mixture is separated by paper chromatography, the position of 2-octulose on the chromatographic paper is determined by developing a carbohydrate reference substance, the paper part is cut off and soaked in methanol, the soaking solution is filtered by a filter membrane and is steamed to dry under reduced pressure, and pure octulose is obtained. The invention provides the method for preparing the 2-octulose standard, and the problem that the lack of 2-octulose standard affects a subsequent research and development is solved. Compared with a method of preparative liquid chromatography, the method is simple in technology, easy to implement and low in cost.

The measurement of gossypol in cotton seed products using conventional methods namely spectrophotometric, NMR methods, chemiluminsecent method, gas-liquid chromatography polarography, thin layer chromatography and paper chromatography are tedious, time-consuming, high cost and needs calibrated systems. In the present invention, a low cost and portable system is devised and the concentration of total gossypol is directly displayed on LCD in mgl-1 or ppm from the test solution and no standard solution is required to make calibration curve for measuring the absorbance.

The invention relates to a new thorium chromogenic agent m-fluoroazophosphine and its synthesis and application, belonging to the technical field of organic reagent synthesis and application. The synthesis method adopts nitration hydrolysis, direct reduction phosphonation, diazotization coupling and other reactions to obtain the crude m-fluoroazofluorophosphine, which is purified by acidification and developed with 25% ammonia water: 5% sodium citrate=2:5. The pure product is obtained by paper chromatography, and has the advantages of short reaction time, complete reaction and simple synthesis process. In the photometric analysis and determination of thorium (IV) by the chromogenic agent, the surfactant hexadecylpyridine bromide is introduced, and the system has a significant sensitization effect after being purified by n-butanol, and has high sensitivity and selectivity , and has certain application value in the analysis fields such as environment and food.

The invention aims at providing a method for identifying spent lubrication oil. The method comprises the step of identifying whether an oil product is spent lubrication oil or not by use of a paper chromatography method or identifying whether fuel oil is mixed with the spent lubricating oil. A chromatographic solution comprises the ingredients of n-heptane, methylbenzene and ethyl alcohol at a volume ratio of 75:15:10. The invention further provides a method for detecting whether a sample contains the spent lubricating oil or not. According to the method, the paper chromatography method is adopted for identification, the chromatographic solution is used for enabling the to-be-detected sample to diffuse on chromatography paper, and whether the sample contains the spent lubricating oil is judged according to the diffusion result of a developing substance. The method has the advantages that needed equipment is simple, field test can be performed in the open air, the capability for recognizing fuel oil doped with the spent lubricating oil is high, and the method can be used for manufacturing a detection toolkit.

The invention discloses a solvent method for preparing DNS (3,5-dinitrosalicylic acid). The solvent method comprises steps of selection of an organic solvent, determination of reactant concentration,determination of reaction time and an experiment, wherein for selection of the organic solvent, the organic solvent in a water-organic solvent mixed medium system can be selected from ethers, alcohols, esters and aldehydes, and repeated experiments prove that a water-methanol-ethylene glycol monoethyl ether mixed medium has the best effect; for determination of the reactant concentration, when thereactant concentration is 8%-20%, the experiments are normal and obvious transformation is absent, however, when the reactant concentration is higher than 25%, a pot redness phenomenon occurs; for determination of the reaction time, paper chromatography is adopted for detecting a reaction endpoint during the experiments, liquid chromatography is adopted for determining DNS purity, the DNS purityis about 50% when reaction is performed for 6 h, the DNS purity is about 95% when reaction is performed for 8 h, and the DNS purity is about 19% when reaction is performed for 10 h.

The present invention relates to a new thorium developer metafluoroazophosphon and its synthesis and application. Said invented synthesis method adopts the reaction steps of nitrating hydrolysis, direct reduction phosphonation and diazo coupling to obtain metafluoroazophosphon crude product, then utilizes the processes of acidification purification and paper chromatography using 25% ammonia water: 5% sodium citrate=2:5 as developing agent to obtain the pure product. By introducing surfactant CPB in the photometric analysis and determination of thorium (IV) said system is purified by adopting n-butanol, it has the obvious sensitivity-enhancing effect, and has high sensitivity and selectivity, and has a certain applicable value in fields of environment and food analysis.

The invention discloses a method for determining the concentration of phosphite by cyclic voltammetry, which comprises the steps of: establishing a working curve by determining the quantitative proportional relation between the oxide peak current intensity of phosphite on a bare Pt electrode and the concentration of phosphite and fitting the working curve as a linear formula, and substituting theoxide peak value of a sample to be detected in the formula to obtain the concentration of phosphite. The method of the invention is accurate in detection results, has the advantages of being simple in experimental conditions, simple and convenient in operation and saving time compared with the traditional methods for determining the concentration of phosphite, such as an oxidation reduction titration method, a paper chromatography, a thin-layer chromatography and an ion exchange chromatography, and has tremendous popularization and application prospect in paint, electroplating and other fields.

The invention discloses a Bacillus sp. to generate non-induced exocytotic chitosanase, which is characterized by the following: detecting enzyme activity of supernatant fermented by strain at 65 deg.c with pH value at 6. 0; displaying the final product as dichitosan and trichitosan through paper chromatography and mass spectrography.