37results about How to "Mild detection conditions" patented technology

The invention discloses a quick detection method of metal mercury, which comprises the following steps: coating biomimetic mineralization of AuNCs and CDs to form a nano composite material CDs / AuNCs (ZIF) ZIF-8 with a ZIF-8 shell layer on the surfaces of the CDs and the AuNCs. The preparation method is based on a room temperature environment CDs / AuNCs (at) ZIF-8 under the excitation of 360nm; twoexcellent emission peaks appear at the positions of 440 nm and 640 nm, fluorescence at the position of 640 nm is quenched in the presence of metal mercury, fluorescence at the position of 440 nm is not affected, and detection of heavy metal mercury is achieved through the fluorescence intensity ratio (I640 / I440). And the detection system has high sensitivity, and the detection can be completed inonly one minute. Along with the increase of the concentration of the metal mercury, under a portable UV lamp, the color change from red to blue is obvious, and the color can be clearly seen by naked eyes. The detection system is high in stability, simple and convenient to operate, high in targeting property, high in sensitivity, low in cost and capable of realizing visual detection.

The invention discloses a method for detecting related substances in flunarizine hydrochloride preparations. The test solution, control solution and impurity mixed solution are respectively taken for high-performance liquid chromatography detection, and each substance in the test product is detected at 210nm and 253nm respectively. Impurity content; where impurity A and 4,4-difluorobenzyl alcohol peaks were detected at 210nm, and the impurity content was calculated by the external standard method; other impurity peaks were detected at 253nm, and the impurity content was calculated by the self-control method. The method of the invention is easy to operate, has short analysis time, strong specificity and high sensitivity, and can effectively separate 7 impurities, including 2 process impurities and 5 degraded impurities. The separation between impurities and adjacent peaks can reach above 1.5.

The invention relates to a coumarin-based relay responsive fluorescent molecular probe and a preparation method and an application thereof and belongs to the technical field of fluorescent chemical sensing materials. The preparation method comprises the following steps of: by taking 4-methylum-belliferyl as a fluorescent group, substituting hydroxyl hydrogen on a site C-7 on 4-methylum-belliferyl by chloroacetyl chloride to form an intermediate compound R; and then performing a substituting reaction on the compound R and 2-methyl pyridinamine as well to combine to prepare the fluorescent molecular probe material. The fluorescent molecular probe prepared by the method has strong blue fluorescent emission. Charge distribution of the probe molecular structure is changed in the presence of Fe<3+>. The blue fluorescence is quenched. After further adding phosphate anions, the fluorescence of the probe is recovered by means of the supplementary effect of metal ions and negative charges, so that the relay identifying detection on Fe3<+> and phosphate anions in a same system is realized, detection and recognition under 100% water soluble condition are realized, and change of the fluorescent signal is macroscopic.

The invention relates to a method for detecting fosfomycin sodium in pharmaceutical wastewater by ion chromatography, the method comprising the following steps: (1) Chromatographic conditions: the chromatographic column is a low-capacity hydroxide system cathodic protection column and a high-capacity anion exchange separation Column, suppressor adopts electrolytic membrane suppressor, conductivity detector, eluent is potassium salt solution; (2) to the preparation of standard solution: get the standard product of fosfomycin sodium and configure it into standard product solution with ultrapure water; (3) Pretreatment of the sample: the sample used for detection is filtered with a 0.45 μm filter membrane and then passed through a C18 small column to remove organic matter in the water sample; (4) Determination method: inject the standard solution into the ion chromatograph, record the spectrum, Determine the position of the standard peak, calculate the area of ​​the fosfomycin sodium peak, draw a standard curve according to the calculated peak area; take the test sample, inject it into an ion chromatograph, record the spectrum, and calculate the concentration of the sample according to the area of ​​the fosfomycin sodium peak. The invention has the advantages of good reproducibility, low detection limit, high sensitivity, simple operation, mild detection conditions, wide application of detection equipment and instruments, wide sources of eluent potassium salt solution, and good detection of fosfomycin sodium in pharmaceutical wastewater. With the advantages of simple configuration, it will be widely used in the detection of fosfomycin sodium in industrial wastewater.

The invention belongs to the technical field of chemical fluorescence sensing materials, and relates to a preparation method and a use of a metal-responsive fluorescence sensing material. The metal-responsive fluorescence sensing material is prepared through a nucleophilic reaction of rhodamine hydrazide and 2-formyl thiazole which are used as base raw materials with methanol as a solvent and acetic acid as a catalyst. The fluorescence sensing material prepared in the invention has good water-solubility and biocompatibility, has a sensitive selective recognition effect on Fe<3+>, is slightly interfered by other common metal ions, and can be effectively complexed with the Fe<3+> to successfully realize the imaging of target ions in biological cells.

The invention belongs to the technical field of simulated enzymes and analytical chemistry, and relates to a colorimetric detection method for alkaline phosphatase activity based on sulfide-modified CoOx, comprising: adding alkaline phosphatase and 1 mM HMPi, reacted for 30-60 min; then added sulfide-modified CoOx suspension, TMB, H 2 o 2 and acetate buffer, mix the system and react for 1 to 30 min; after passing through the membrane, record the absorbance at a wavelength of 652 nm with a UV-visible absorption spectrophotometer; compare the absorbance measurement value of the above TMBox with the corresponding ALP activity Draw the calibrated ALP activity-absorbance standard working curve; repeat the above steps for the ALP sample to be tested, and compare it with the standard working curve to obtain the ALP activity. The detection process of the invention has mild conditions, does not require other reagents, realizes convenient and rapid detection of ALP activity, low detection cost, simple operation, wide detection range of 0.8-320 U / L, and realizes detection of alkaline phosphoric acid in human serum Detection of enzyme activity.

The invention discloses a glutamic acid oxidase biosensor, a preparation method and an application thereof, and belongs to the technical field of electrochemical biosensors. The working electrode of this biosensor is made of PtNP@MXene‑Ti 3 C 2 T x solution, glutamate oxidase solution and chitosan solution modification, the preparation methods include: MXene‑Ti 3 C 2 T x The solution was mixed with chloroauric acid solution, sonicated and continuously reduced to obtain PtNP@MXene‑Ti 3 C 2 T x After the solution, it was drip-coated on the surface of the glassy carbon electrode, dried in a dust-free environment, and then modified with chitosan to glutamate oxidase on the surface, and refrigerated until completely dry. The enzyme biosensor of the invention can be used to detect the content of sodium glutamate (MSG) in food, and has high sensitivity, low detection limit and good anti-interference performance.

The invention relates to the technical field of food processing, in particular to a method for determining eight sweetening agents in Baijiu by a high-performance liquid chromatography-low-temperature evaporative light scattering detector method. The method includes the steps of (1), standard solution preparation, (2) sample pretreatment, (3) sample detection, (4) calibration curve establishment and (5) resulting. The method for determining eight sweetening agents in the Baijiu by the high-performance liquid chromatography-low-temperature evaporative light scattering detector method has the advantages of mild detection conditions, simplicity, rapidity, good separation effects and capability of playing a positive role in improving laboratory detection efficiency and reducing detection cost.

The invention belongs to the technical field of chemical fluorescent sensing materials, relates to a preparation method and use of a coumarin derivative-based fluorescent sensing material, and provides a coumarin derivative-based fluorescent sensing material. The material is a fluorescent chemical sensing material prepared by taking 7-hydroxycoumarin and levulinic acid as basic raw materials, taking dichloromethane as a solvent, adding N,N-diisopropylcarbodiimide to remove water molecules from the carboxyl of the levulinic acid to turn the levulinic acid into acid anhydride, adding 4-methylaminopyridine to neutralize the excessive levulinic acid and performing nucleophilic reaction. The prepared fluorescent sensing material is high in water solubility and biocompatibility and quick in response, and has sensitive selective recognition performance for SO3<2->, changes in fluorescence signals are visible to eyes under an ultraviolet lamp, the interference of other common anions is little, and target ions in a biological cell are successfully imaged.