262 results about "Ultraviolet absorption spectrum" patented technology

The invention discloses a method for extracting and purifying polysaccharide from a fermented mycelium of Cordyceps sinensis. The method comprises the following steps of: using the fermented mycelium of Cordyceps sinensis as a raw material to produce crude polysaccharide of the Cordyceps sinensis via degreasing, aqueous extraction, concentration and alcohol precipitation; then, redissolving the crude polysaccharide into distilled water, deproteinizing the crude polysaccharide by Sevag, decoloring the deproteinized crude polysaccharide by H2O2, dialyzing the decolored crude polysaccharide, and precipitating the dialyzed crude polysaccharide by alcohol to produce primarily purified polysaccharide; finally, purifying the primarily purified polysaccharide by ion-exchange chromatography, collecting different produced compositions stepwisely, dialyzing the compositions, precipitating the dialyzed compositions by alcohol, drying the precipitated compositions to produce the polysaccharide of the Cordyceps sinensis after the precipitated compositions are orderly washed by absolute ethyl alcohol, acetone, aether and so on. In the produced polysaccharide of the Cordyceps sinensis, MPS2 is identified to be homogeneous polysaccharide by ultraviolet absorption spectrum and gel chromatography, with high content of total sugar. The method has the advantages of simple and convenient extraction steps and low cost.

The invention relates to an iridium complex containing a boron mesityl unit, a preparation method and the application thereof as a fluorescent probe. An ultraviolet absorption spectrum and a fluorescence emission spectrum are utilized to detect the influence on the photophysical property and an energy transfer process of the complex by adding fluorinions. The complex has high material luminous efficiency and utilizes specific binding of boron mesityl and the fluorinions in a ligand. After the fluorinions are added, the excited-state property of the complex changes, and the energy transfer process also changes to enable the characteristic emission intensity of the iridium complex to be gradually lowered and finally quenched and the blue light emission intensity of an oligomerization ligand to gradually rise, thereby realizing a phosphorescence fluorion probe based on the color comparison and the ratio identification.

A polymer film is used as an optical compensatory sheet or a support thereof. The polymer film contains a rod-like compound. The rod-like compound in the form of a solution gives an ultraviolet absorption spectrum. In the spectrum, the wavelength of λmax at the maximum absorption peak is shorter than 250 nm. The spectrum of the rod-like compound is measured when the rod-like compound is in the form of solution. The polymer film has an Rth retardation value of Rth450 measured at the wavelength of 450 nm in the range of 30 to 160 nm. The polymer film also has an Rth retardation value of Rth590 measured at the wavelength of 590 nm in the range of 50 to 200 nm. The values of the Rth450 and Rth590 satisfy the condition of Rth590-Rth450≧2 nm.

The invention provides a porphyrin optical sensing functional film suitable for detecting heavy metal ions. The material takes a polymer film as a solid substrate and porphyrin as an optical indicator; the polymer film realizes loading of porphyrin through a non-covalent bond or a covalent bond. After the film and the heavy metal ions with the concentration being greater than 0.01mg/L generate reaction, the color and an ultraviolet absorption spectrum are changed and can be recovered after being treated by an acidic and/or EDTA solution; the process can be repeated. Therefore, the preparation method of the functional film is simple and feasible; detection for the heavy metal ions has the characteristics of convenience, intuitiveness and high reproducibility.

The invention discloses a smoke mercury emission monitoring system and method. The smoke mercury emission monitoring system comprises a sampling device, a pre-processing device and a mercury monitoring device, wherein the sampling device is used for collecting smoke when the system works; the pre-processing device comprises a catalytic reactor which is used for converting mercury in an oxidation state to the mercury in an element state; the mercury monitoring device comprises an ultraviolet light source, a measuring cell and a mercury analyzer; the measuring cell is used for absorbing ultraviolet lights through the pro-processed smoke; and the mercury analyzer is used for recording the absorbance of the absorption and calculating a concentration of the mercury according to the absorbance. According to the smoke mercury emission monitoring system disclosed by the invention, the mercury content in the smoke is directly monitored by using an ultraviolet absorption spectrum without a mercury gathering unit. The smoke mercury emission monitoring system has a fast measurement speed and can be used for continuously monitoring in real time in true sense.

The invention discloses a method for detecting tripolycyanamide based on nanogold mimetic peroxidase. Nanogold stimulates the change of the activity of the peroxidase after being interacted with tripolycyanamide, hydrogen peroxide is catalyzed by nanogold to oxidize 3,3',5,5'-tetramethylbenzidine dihydrochloride so as to be conducted for color development, therefore, the change of the color of a solution and the characteristics of an ultraviolet absorption spectrum are shown. The detection limit of the visual observation is 0.02mg/L. The linear range detected by the optical density is 5-80 mug/L, and the detection limit is 1.2 mug/L. The content of tripolycyanamide in a milk powder sample can be detected well by the method after being simply preprocessed.

The invention belongs to the field of analytical chemistry, and discloses a method for measuring multiple types of ATP (adenosine triphosphate) associated products in an aquatic product with a high performance liquid chromatography-diode array method. A high performance liquid chromatograph provided with a diode array detector is used for detection, and a to-be-detected sample is fed into the high performance liquid chromatograph for gradient elution after extracted; which ATP associated product each chromatographic peak belongs to is determined according to the retention time and the ultraviolet absorption spectrum of the ATP associated product, the corresponding ATP associated product chromatographic peak area is detected, and the content of the ATP associated products in a to-be-detected sample extracting solution is calculated according to an ATP associated product standard work curve or regression equation under the same chromatographic condition. According to the method, requirements for equipment and analysis conditions are simple, the content of multiple types of ATP associated products in the aquatic product can be measured simultaneously without adopting an ion-pairing agent, ten types of ATP associated products can be measured simultaneously, and the separating time doesn't exceed 25 minutes.

The invention discloses a fluorescent probe for dopamine determination. The fluorescent probe for the dopamine determination is characterized in that with L-arginine as a carbon source, one-step synthesis of carbon quantum dots with strong fluorescence emission is achieved through a hydrothermal method; the carbon quantum dots are characterized by such things as ultraviolet absorption spectrum (UV), fluorescence spectrum (PL), fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), and fluorescent properties of the synthetic carbon quantum dots and the fact that the surface of the same contains a large number of functional groups such as hydroxyl groups and carbonyl groups are confirmed; according to the fluorescence quenching effect of dopamine on C-dots(carbon dots), the C-dots are used as a fluorescent probe for detecting the dopamine, and experimental conditions such as pH (hydrogen ion concentration), carbon point usage, reaction temperature andtime are optimized; a quantitative detection method for the dopamine is established under the optimal detection conditions, and the detection limit is as low as 93 nanometers, which proves that the method can be used for sensitive detection of dopamine in actual samples.

The invention relates to a solution concentration on-line detection method in the solventing-out crystallization process and a special device thereof. The method comprises the following steps: A. filtering samples through a sampling tube with a microfilter arranged at the front end for filtering and removing crystal grains in solution, and then, using a sampling pump for continuously pumping the samples from a crystallization kettle and conveying the samples to a detection tank; B. adopting a ultraviolet optical fiber spectrometer for continuously recording the ultraviolet absorption spectrum of the solution in the detection tank and transferring the ultraviolet absorption spectrum to a computer to be recorded in real time, and making the tested solution flow back to the crystallization kettle; and C. after correcting the continuously recorded ultraviolet detection spectrum in the computer by an orthogonal signal correction OSC method, taking the light absorbance value R under any wave length within 200nm to 400nm from the ultraviolet region, using a least square method to obtain a calculation factor in a Lambert-beer law calculation method, and further working out the solute concentration x of the solution to be tested in certain time. The method has the advantages of short detection time, capability of realizing on-line detection, small temperature influence, high precision, good reproducibility, simple detection device and low cost.

The invention relates to a method for detecting telomerase activity with a colorimetric method based on strand displacement reaction. According to the method, in the presence of active telomerase, hybridization is performed on a prolonging product of a substrate with assistant DNA so as to release a plurality of triggering DNAs, the triggering DNAs can trigger hairpin DNA probes H1 and H2 to have self-assembled strand displacement reaction, then G-4 chains are respectively formed at two tail ends of H1:H2, hemin reacts with the G-4 chains, thus G-4 chain DNA enzyme with catalytic activity can be formed, a TMB-H2O2 system is catalyzed to have reaction, the color of a solution is changed into blue from colorless, and the solution can be oxidized into yellow if acid is added; due to addition of active telomerase, the color of the solution can be changed, visible detection on telomerase activity can be achieved, meanwhile an ultraviolet absorption spectrum of the solution can be tested, and the telomerase activity can be more accurately and sensitively tested.

The invention provides an optical system based on a portable efficient-measurement ultraviolet absorption spectrum. The optical system consists of an ultraviolet light source collimation optical system, a multi-reflection basin optical system and a focusing and coupling fiber optical system. The ultraviolet light source collimation optical system consists of an ultraviolet light source and three lenses; the multi-reflection basin optical system adopts a manner of placing three concave-spherical reflection lenses with three curvature radiuses in a conjugated manner; and the focusing and coupling fiber optical system uses a non-spherical single lens to focus and couple outgoing beams for an optical fiber, so that the outgoing beams are guided to a spectrometer for probing. According to the optical system provided by the invention, the detection resolution of the entire system is improved, the measurement accuracy is ensured, and the entire optical system is portable and compact.

The invention discloses a method for detecting cyanide ions based on gold nanorods, comprising the following steps: preparing gold nanorod solution, reacting the gold nanorod solution with a series of cyanide ion standard solutions, drawing a working curve through linear variations of ultraviolet absorption spectrum and/or two-photon excited fluorescent spectrum to obtain a linear equation with one unknown, measuring a sample by a corresponding scanning method, and taking a spectral value of the sample to the linear equation with one unknown for the standard working curve to calculate a sample concentration value. The preparation process of the gold nanorods is simple and convenient and is nontoxic and environment-friendly, the synthesized gold nanorods are uniform in size and good in stability and can react sensitively and quickly with cyanide ions in a water environment, cyanide ions in the water environment can be detected quickly and sensitively by using both ultraviolet spectrophotometry and two-photon excited fluorescence method, and lowest detection limit of ultraviolet spectrophotometry is up to 0.5 MuM, with lowest detection limit of the two-photon excited fluorescence method up to 0.01 MuM.

The invention discloses a photoreaction monomer and a liquid crystal composition and a vertical alignment liquid crystal panel with the same. According to the photoreaction monomer provided by the invention, by increasing the length of a hard core, the absorption wavelength range of the ultraviolet absorption spectrum of the monomer is superposed with the wavelength range of an ultraviolet lamp to a great extent, thus the curing speed of the photoreaction monomer disclosed by the invention is higher than that of the existing RM, and the phenomenon of image sticking caused by high amount of residues of the monomer is avoided.

The invention relates to a method for measuring protection of a sunscreen cosmetic, which is characterized by comprising the following steps: a solution to be tested and a blank reference solution containing no cosmetic to be measured are prepared; then an integrating sphere is arranged between an absorption pond and a detector in an ultraviolet-visible spectrophotometer, the blank reference solution is employed for blank correction on the ultraviolet-visible spectrophotometer; the solution to be tested is added in the absorption pond of the ultraviolet-visible spectrophotometer finally, the solution to be tested is tested, the ultraviolet absorption spectrum of the solution to be tested is measured, and the cosmetic to be measured has better protection effect due to higher absorbance. According to the invention, the ultraviolet-visible spectrophotometer of the integrating sphere is increased for measuring the absorbance of the cosmetic to be measured, thereby the sunscreen effect of the cosmetic to be measured can be measured, the measurement method has the advantages of simple operation, low measurement cost, high credibility and accuracy, and easy popularization and application.

The invention belongs to the field of innovative drugs and cosmetics, and particularly relates to a 1,3,6,7-tetrahydroxy xanthone derivative shown in the formula (I) and the formula (II) and a preparing method and application of the derivative to medicine and cosmetics. The derivative is prepared through an olefination reaction. An ultraviolet spectrophotometer is adopted to measure the ultraviolet absorption spectrum of the compound in the 280-400 nm ultraviolet interval, and the result shows that the 1,3,6,7-tetrahydroxy xanthone derivative has ultraviolet absorption capacity and the ultraviolet radiation resisting function and can be applied to cosmetics serving as a sun-screening agent or being compounded with other sun-screening agents. The result of in-vitro acid sphingomyelinase inhibitory activity tests shows that the compound has acid sphingomyelinase inhibitory activity and can be applied to preparation of drugs for preventing and treating diseases related to acid sphingomyelinase serving as an acid sphingomyelinase inhibitor, wherein cardiovascular and cerebrovascular diseases, nervous system diseases, hepatic diseases, lung diseases, autoimmune diseases, infectious diseases, cancers and the like are mainly involved.

The invention discloses a quick measuring method for content of copper ions by heat-treated bare nano-gold as a developing probe. Surface effect of the heat-treated bare nano-gold with the copper ions causes gathering of nano-gold, and accordingly changes in characteristics of the color of solution and the ultraviolet absorption spectrum are shown. The characteristics of the color of the heat-treated bare nano-gold solution are observed visually to judge the concentration of the copper ions, and detection limit of visual observation is 2 micrometers mol/L. The concentration of the copper ions is judged according to the ratio of light absorbance of the heat-treated bare nano-gold A650/A515. A linear range of measuring the ratio of the light absorbance is 0.5-6micrometers mol/L, and the detection limit is 0.04micrometers mol/L.

The invention discloses a method for rapid determination of sulphur ions with nanogold as a logic gate color developing probe. As thiourea can enable aggregation of a nanogold solution, the solution changes from wine red to blue, and sulphur ions can specifically inhibit thiourea from aggregating nanogold, variation of the solution color and ultraviolet absorption spectrum characteristics can be shown, so that the sulphur ion concentration can be determined. Thiourea can make the nanogold solution undergo aggregation and change the solution color from wine red to blue, while sulphur ions can specifically inhibit thiourea from aggregating nanogold, thus showing variation of the solution color and ultraviolet absorption spectrum characteristics. The limit of detection of visual observation is 4 micromol/L. The linear range of absorbance ratio determination is 2-9 micromol/L. After simple pretreatment, mineral water, tap water, river water, white grape wine, human urine and other actual samples can be subjected to sulphur ion content determination by the method.

The invention relates to double-schiff-base based on naphthol, synthesis thereof and application thereof as a fluorinion sensor molecule. The invention provides the fluorinion sensor molecule, namely the double-schiff-base based on naphthol, wherein the double-schiff-base is faint yellow and almost free of fluorescence in a dimethyl sulfoxide solution; when fluorinions are added into the solution, the solution emits stronger blue fluorescence at the position of 467 nm immediately, the ultraviolet absorption spectrum of the solution has a red shift of 20 nm, and meanwhile the solution becomes deep yellow immediately; when other negative ions are added in, the fluorescence and color of the solution with the sensor molecule are not changed almost, so that the sensor molecule can identity fluorinions through single fluorescence, and the identification process cannot be disturbed by the other negative ions. Through titration experimental determination, the minimum detection line of the sensor molecule to the fluorinions can reach 1.4*10<-8> mol/L, which is far lower than the detection standard of fluorinions in drinking water, thus the double-schiff-base can be used for detecting the content of the fluorinions in the drinking water.

The invention discloses a spectroscopic seawater nitrate concentration detection method which comprises the following steps: 1) measuring a seawater spectrum by using an ultraviolet spectrophotometry,and calculating absorbance to obtain an ultraviolet absorption spectrum of seawater; 2) carrying out smoothing pretreatment on the seawater ultraviolet absorption spectrum; 3) sequentially carrying out seawater chloride ion, bromide ion and turbidity interference deduction on the absorption spectrum; and 4) establishing a partial least squares model by utilizing the absorption spectrum subjectedto smooth pretreatment and interference deduction, and optimizing selection of a modeling waveband to obtain a seawater nitrate concentration partial least squares method final meter. The spectroscopic seawater nitrate concentration detection method provided by the invention can effectively reduce errors caused by random noise when the seawater nitrate concentration is measured by the spectrography, can reduce interference caused by other substances with absorption to an ultraviolet band in seawater, and can improve the nitrate concentration prediction precision.

The invention discloses a high-speed counter-current chromatography method for separating main aroma components in tree moss concrete, which comprises the following steps: 1) mixing n-hexane, ethyl acetate, ethanol and water in a volume ratio of (0.6-1.2):(0.6-1.2):(0.7-1.2):(0.7-1.2), vigorously vibrating, and standing until the solution is divided into two layers, wherein the upper layer is a stationary phase, and the lower layer is a mobile phase; 2) dispersing the tree moss concrete with the mobile phase to obtain a sample solution to be separated; and 3) separating the sample solution by high-speed counter-current chromatography, collecting the corresponding fraction according to the ultraviolet absorption spectrum, and carrying out solvent removal technique on the fraction to obtain a cigarette additive in which the relative content of the main aroma components in the tree moss concrete is higher than 85%. The impurities in the original tree moss concrete are removed, and no new impurities and toxic substances are introduced into the cigarette additive, thereby obviously improving the inherent esthetic quality of the cigarette; and thus, the cigarette additive has wide application prospects in cigarette perfuming.

A coating that can be adhered to a polyethylene gasoline container to substantially reduce its gas permeability, and a gasoline container treated with such a coating. A single-component cationic curing composition with increased impermeability to gasoline vapor uses a bis “F” epoxy in combination with a catalyst and oxetane. The invention takes advantage of a narrower ultraviolet absorption spectrum of the bis “F” epoxy, whereby ultraviolet radiation outside the UV absorption spectrum of the bis “F” will activate the catalyst, the highly active superacid from the antimonate anion, without any significant reduction of the cationic curing reaction. In the preferred embodiment the bis “F” and oxetane combination is used along with various additives included for flow and cosmetic purposes.