220 results about "Molar concentration" patented technology

The invention provides an aluminum electrolyte recycling method which comprises the following steps: (1) mixing an aluminum electrolyte and a leaching agent solution, and carrying out slurrying leaching to obtain slurry and hydrogen fluoride gas; the molar concentration of hydrogen ions in the leaching agent solution is 2.5-25 mol / L; (2) carrying out liquid-solid separation on the slurry obtained in the step (1) to obtain leaching liquid and leaching residues, and carrying out post-treatment on the leaching residues to obtain basic aluminum fluoride; the immersion liquid is reused in the step (1). According to the method, the aluminum electrolyte can be completely dissolved in the strong acid solution under the conditions of high temperature and high pressure, so that the high-purity alkaline aluminum fluoride product is obtained, the recovery rate of aluminum and fluorine resources is high, the immersion liquid can be recycled, the technological process is simple, and the method has a wide application prospect.

The present invention belongs to the technical field of petroleum fracturing production enhancement and modification, and specifically discloses a fracturing fluid pre-fluid for optimizing the size of in-situ autogenous proppant and its application, which is used to solve the problem of small particle size of proppant particles generated by hydrothermal reaction of formation minerals. The fracturing fluid pre-fluid is suitable for calcium-rich reservoirs and is composed of clean water, phosphate, pH regulator and Ca 2+ The chelating agent composition comprises 1 to 10 parts by weight of phosphate relative to 100 parts by weight of clean water, a volume molar concentration of the pH regulator is 1 to 5 mol / L, and Ca 2+ The molar concentration of the chelating agent is 0.001~1mol / L; the pH regulator is urea, ammonia, propionamide, etc. 2+ The chelating agent is EDTA, glutamic acid, etc. The present invention increases the average particle size of proppant particles generated by hydrothermal reaction of formation minerals, thereby improving the supporting effect thereof in micro-fractures of the formation.

The invention belongs to the technical field of methane leakage monitoring, and discloses a method and a system for estimating methane leakage flux of an ocean station movable cold spring. The method comprises the following steps: acquiring physical states of bubbles at different depths of a station cold spring area and physicochemical properties of methane gas in the different depths of the station cold spring area, and obtaining a station cold spring plume three-dimensional static molar concentration model; calculating the molar flux of methane in a bubble state and the rising speed of bubbles to obtain the eruption rate of the seabed cold spring nozzle; and calculating the annual cold spring methane leakage flux of the station by combining the station cold spring plume three-dimensional static molar concentration model, the eruption rate and the bubble rising speed with the periodic leakage characteristics of the cold spring plume. The methane flux of the station cold spring leakage is 6.44 * 10 < 5 > mol / yr, which is greater than the previous estimation result. Previously, understanding of contribution of methane leakage of a cold spring system to climate change and carbon cycle is underestimated.

The invention belongs to the technical field of petroleum fracturing yield increase transformation, and particularly discloses fracturing fluid prepad fluid for optimizing the size of an in-situ authigenic proppant and application of the fracturing fluid prepad fluid, which are used for solving the problem of small particle size of proppant particles generated by a formation mineral hydrothermal reaction in the prior art. The fracturing fluid prepad fluid is suitable for a calcium-rich reservoir and is composed of clear water, phosphate, a pH regulator and a Ca < 2 + > chelating agent, relative to 100 parts by weight of clear water, the content of the phosphate is 1-10 parts by weight, the volume molar concentration of the pH regulator is 1-5 mol / L, and the volume molar concentration of the Ca < 2 + > chelating agent is 0.001-1 mol / L; the pH regulator is urea, ammonia water, propanamide and the like, and the Ca < 2 + > chelating agent is EDTA (Ethylene Diamine Tetraacetic Acid), glutamic acid and the like. The average particle size of the proppant particles generated by the formation mineral hydrothermal reaction is increased, and the supporting effect of the proppant particles in formation microfractures is improved.

A gas separation method includes supplying a mixed gas to a zeolite membrane complex and permeating a high permeability gas through the zeolite membrane complex to separate the high permeability gas from other gases. The mixed gas includes a high permeability gas and a trace gas that is lower in concentration than the high permeability gas. The molar concentration of a first gas included in the trace gas in the mixed gas is higher than the molar concentration of a second gas included in the trace gas in the mixed gas. The adsorption equilibrium constant of the first gas on the zeolite membrane is less than 60 times that of the high permeability gas. The adsorption equilibrium constant of the second gas on the zeolite membrane is 400 times or more that of the high permeability gas.

The invention provides a method for detecting PFAS based on a three-dimensional Ag / NiFe-LDHs surface enhanced Raman scattering substrate and ion pair extraction, and belongs to the technical field of PFAS detection.The method comprises the steps that firstly, the three-dimensional Ag / NiFe-LDHs SERS substrate is prepared, then ion pair extraction-dissociation treatment is conducted on a water sample to be detected, a detection solution is obtained, finally, the substrate is immersed in the detection solution for adsorption, and finally the detection solution is obtained. A spectrum is collected through a Raman spectrometer, and semi-quantitative detection of PFAS in a water sample is achieved according to the linear relation between the characteristic peak intensity and the PFAS molar concentration logarithm. According to the method, collaborative application of the three-dimensional Ag / NiFe-LDHs SERS substrate and an ion pair extraction technology and indirect detection of PFAS are realized, the detection difficulty that PFAS Raman signals are weak and are difficult to enrich is improved, the detection sensitivity and adaptability of PFAS in a water sample are improved, and an application foundation is laid for rapid monitoring of PFAS pollution of an environmental water body.

The invention provides a preparation method of high-specific-surface-area silver particles for low-temperature sintered silver paste, and belongs to the technical field of conductive materials, and the preparation method comprises the following steps: adding ammonia water into a hydrazine hydrate solution with the molar concentration of 1.60-6.0 mol / L until the pH value of the hydrazine hydrate solution is 10-13; the method comprises the following steps: preparing an alpha-amino acid aqueous solution with the molar concentration of 0.012-0.048 mol / L at the temperature of 35-45 DEG C; the preparation method comprises the following steps: dropwise adding a hydrazine hydrate solution and a silver nitrate solution into an alpha-amino acid solution at the same time within 8-12min, stirring, heating, adding a sodium hydroxide solution to adjust the pH value of a reaction solution to 11-13, continuously stirring, aging, separating, washing and drying to obtain the silver particles with high specific surface area. On the premise of ensuring the conductivity of the high-specific-surface-area silver particles, the particle size and the specific surface area of the silver particles are controllable, the requirement for the stability of the silver powder serving as the conductive filler is met, and the yield is high.

The invention discloses three-dimensional porous copper and a preparation method thereof.The preparation method of the three-dimensional porous copper comprises the following steps that a copper alloy matrix is provided, the copper alloy matrix comprises a Cu element and a non-Cu metal element, and the standard electrode potential of the non-Cu metal element is smaller than that of the Cu element; a corrosive liquid is provided, the corrosive liquid comprises neutral salt, a weakly acidic complexing agent and a solvent, the molar concentration of the neutral salt is recorded as C1, the molar concentration of the weakly acidic complexing agent is recorded as C2, the unit is mol / L, C2 / C1 is larger than or equal to 0.04 and smaller than or equal to 0.60, and C2 is smaller than or equal to 0.20 mol / L; and the copper alloy matrix is subjected to electrochemical corrosion with the corrosive liquid as electrolyte, and the three-dimensional porous copper is obtained. The porosity of the three-dimensional porous copper can be improved, and cracks of the three-dimensional porous copper can be reduced.

The invention discloses a rare earth polishing solution for chemical mechanical polishing of monocrystal diamond as well as a preparation method and application of the rare earth polishing solution. The rare earth polishing solution comprises a rare earth abrasive, a solvent, a dispersing agent and an oxidizing agent, in the rare earth polishing solution, the mass concentration of the rare earth abrasive is 0.1%-1%, the percentage concentration of the dispersing agent is 1%-2%, the molar concentration of the oxidizing agent is 0.5-1 mol / L, and the solvent is deionized water. The preparation process method is simple, and the product has excellent polishing performance.

The invention discloses a cerium oxide material and a preparation method thereof.The preparation method comprises the following steps that 1, inorganic ammonium salt is added into a cerium salt aqueous solution under stirring, stirring continues to be conducted for 1-3 h after adding is completed, and a first reactant is obtained; wherein the molar ratio of cerium salt to inorganic ammonium salt in the cerium salt aqueous solution is 1: (4.7-5.3), and the inorganic ammonium salt is ammonium carbonate and / or ammonium bicarbonate; the molar concentration of cerium salt in the cerium salt aqueous solution is 0.08-0.2 mol / L; 2) performing hydrothermal reaction on the first reactant at 180-200 DEG C for 7-24 hours to obtain a second reactant; 3) carrying out solid-liquid separation on the second reactant, washing the separated solid, and drying the washed solid to obtain a precursor; and 4) roasting the precursor at 600-900 DEG C for 2-5 hours to obtain the cerium oxide material. The preparation method can be used for obtaining the cerium oxide material with the particle size of 100-200nm and the general popcorn-shaped morphology.

The invention is suitable for the application field of electrolyte acidity determination, and provides a method for determining the acidity of an all-vanadium electrolyte based on a complexing mass difference method, and the method comprises the following steps: taking the all-vanadium electrolyte, and diluting the all-vanadium electrolyte into a pretreated all-vanadium electrolyte with the concentration of 0.05-0.1 mol / L; adding 1.5-2mL of a complexing masking reagent with the molar concentration of 1.5-2mol / L, weighing, and recording as M1; stirring and titrating, weighing and recording as M2; a quantitative determination method of mass difference is used for calculation, and the formula is {(M2-M1)-0.05} / A * C. In conclusion, a mass difference quantitative determination method is adopted, the vanadium complexing masking reagent is added, the adding amount and the pH value of the vanadium complexing masking reagent are controlled, a stable complex is formed through the complexing masking reagent, vanadium ions and impurity ions, the oxidation-reduction reaction and the precipitation reaction of the complex and sodium hydroxide are inhibited, and the accuracy of the acidity value of the all-vanadium electrolyte is improved.

A gas separation method includes supplying a mixed gas to a zeolite membrane complex and permeating a high permeability gas through the zeolite membrane complex to separate the high permeability gas from other gases. The mixed gas includes a high permeability gas and a trace gas that is lower in concentration than the high permeability gas. The trace gas contains an organic substance whose molar concentration in the mixed gas is higher than or equal to 1.0 mol %. The adsorption equilibrium constant of the organic substance on the zeolite membrane is less than 150 times the adsorption equilibrium constant of the high permeability gas.

The invention discloses a method for preparing iron phosphate and aluminum oxide by utilizing step-by-step leaching of red mud, which comprises the following steps: (a) carrying out ore grinding treatment on the red mud to obtain red mud powder with preset fineness; (b) adding the red mud powder into mixed acid, carrying out acid leaching treatment at 30-50 DEG C, carrying out ultrasonic treatment assisted in the acid leaching process to obtain a leaching mixed solution, and carrying out solid-liquid separation on the leaching mixed solution to obtain leaching residues and a leaching solution containing iron and aluminum ions; the mixed acid is a mixed solution of hydrochloric acid, oxalic acid and phosphoric acid, the molar ratio of hydrochloric acid to oxalic acid is (2-5): (2-5), and the ratio of the amount of phosphoric acid substance to the amount of iron substance in the red mud is (0.9-1.2): 1; the molar concentration of H < + > in the mixed acid solution is 4-10 mol / L; (c) adjusting the pH value of the leachate, carrying out auxiliary stirring reaction under a set temperature condition, and then aging and filtering to obtain crude iron phosphate and filtrate; (d) calcining the crude iron phosphate, and cooling to obtain battery-grade iron phosphate; (e) adjusting the pH value of the filtrate, carrying out auxiliary stirring reaction under a preset temperature condition, and then aging and filtering to obtain aluminum hydroxide precipitate; and (f) calcining the aluminum hydroxide precipitate, and cooling to obtain the aluminum oxide.

The invention discloses a method for measuring the molar concentration of nano-particles. The method comprises the following steps: diluting a nano-particle suspension with a high-molecular polymer solution or dispersing nano-particle powder into the high-molecular polymer solution; transferring the suspension liquid to a spacing net on the side of a sample pool in an electrophoresis tank; nano-particles migrate from the sample pool to the buffer pool under the driving of the electric field and are uniformly distributed on the spacing net in a single-particle manner; performing single-particle imaging on the spacing net by using an optical microscope; and counting the number of the nanoparticles in the image so as to measure the molar concentration of the nanoparticles in the sample. The method can be used under the condition that the properties of the nanoparticles are unknown or no standard substance exists, the detection object has no additional condition, and the accuracy is high.

The invention provides copper-doped iron sulfide as well as a preparation method and application thereof, and the preparation method of the copper-doped iron sulfide comprises the following steps: S1, preparing a metal salt solution from iron nitrate and copper nitrate; wherein in the metal salt solution, the sum of the molar concentration of iron ions and the molar concentration of copper ions is 0.003 mol / 25 ml to 0.06 mol / 25 ml; s2, dissolving a sulfur source in a metal salt solution to obtain a mixed solution, heating the mixed solution to 120-180 DEG C under a high-pressure condition, carrying out heat preservation for 12 hours, and separating solids in the mixed solution to obtain copper-doped iron sulfide; the molar concentration of the sulfur source in the mixed solution is 0.01-0.1 mol / 50ml; or, the metal salt solution is heated to 120-180 DEG C under the high-pressure condition, heat preservation is conducted for 12 h, a precursor is obtained, the precursor and elemental sulfur are mixed and then heated to 400 DEG C, heat preservation is conducted for 2 h, and the copper-doped iron sulfide is obtained. The adsorption capacity of the ferric sulfide mercury is improved, and meanwhile, the method has a remarkable economic advantage in the aspect of HgO removal.

The invention provides a preparation for blood purification and a preparation method and application thereof.The preparation is in a solid state or a liquid state, L-malic acid serves as a pH regulator of the preparation, calcium citrate and calcium chloride are used for providing total calcium, the total calcium addition value of the preparation is 1.0-1.5 mmol / L, and the total calcium addition value of the preparation is 1.0-1.5 mmol / L. A dialysate for clinical application of the preparation contains ionized calcium and molecular calcium at the same time, the molar concentration ratio of the ionized calcium to the molecular calcium is 2-6, the ratio of the total calcium addition value to the molar concentration of the citrate radical is 10-12, the molar concentration ratio of the citrate radical to the L-malic acid is 0.05-0.15, and the molar concentration ratio of the citric acid radical to the L-malic acid is 0.05-0.15. The calcium chloride, the calcium citrate and the L-malic acid are reasonably proportioned, so that the supply of 80-85% of effective free calcium can be realized on the premise of ensuring a low total calcium addition value, thereby obviously reducing adverse reactions caused by low calcium or high calcium in the dialysis process, and effectively preventing and controlling dialysis syndromes and the problem of calcium ion disorder possibly occurring after dialysis.

The invention belongs to the technical field of resource regeneration, and particularly relates to a method for extracting and recovering germanium from a germanium-containing waste hydrochloric acid solution. The method comprises the steps of extraction separation, reverse extraction and germanium deposition enrichment. According to the method, amyl butyrate is adopted to extract and regenerate germanium from the germanium-containing high-concentration waste hydrochloric acid solution, and the method has the advantages that an extracting agent is more stable and environmentally friendly, the method is suitable for the germanium-containing hydrochloric acid solution with the HCl molar concentration larger than or equal to 6.5 mol / L, germanium and hydrochloric acid can be regenerated synchronously, the germanium recovery rate is higher, the recovery cost is lower, the process is simpler and the like.

The present invention belongs to the field of resource regeneration technology, and specifically relates to a method for extracting and recovering germanium from waste hydrochloric acid solutions containing germanium. The method comprises extraction and separation, stripping, and precipitation and enrichment of germanium. The method utilizes amyl butyrate to extract and regenerate germanium from high-concentration waste hydrochloric acid solutions containing germanium. This method has the advantages of a more stable extractant, environmental friendliness, compatibility with germanium-containing hydrochloric acid solutions with a molar concentration of HCl greater than or equal to 6.5 mol / L, simultaneous regeneration of germanium and hydrochloric acid, higher germanium recovery rates, lower recovery costs, and a simpler process.

The present solution provides a hybrid coagulant based on aluminum-iron silicate, where the molar concentration of silicon is in the range of 0.1 to 0.5 mol∙l-1, the molar ratio of the sum of aluminum and iron to silicon is in the range of 1:0.5 to 1:1.5, the molar ratio of aluminum to iron is in the range of 0.5:1 to 5:1, and a method of its preparation by mixing hydrated aluminum sulfate, hydrated iron sulfate and an acidic solution of silicon dioxide.

The invention discloses a method for purifying Z-phenylalanyl tryptophan. The method mainly solves the technical problem that related by-products generated in the production process are difficult to remove. The purification method comprises the following steps: 1, preparing a reagent for preparation; 2, pre-treating a sample; 3, high performance liquid chromatography determination is carried out, a chromatographic instrument is an Agilent 1260 chromatographic instrument, a VWD ultraviolet detector is adopted, a chromatographic column adopts Waters Sun Fire C18, and a mobile phase is a solution A (A) with the molar concentration of 0.05% and an acetonitrile solution (B) with the mass percentage concentration of 100%; the method provides a reliable and convenient means for improving the purification purity of the Z-phenylalanyl tryptophan.

The invention relates to a synthesis method of dimethyl oxalate, and mainly solves the technical problems of high reaction hot spot temperature, poor dimethyl oxalate selectivity and low space time yield in the prior art. According to the technical scheme, carbon monoxide, nitrogen and methyl nitrite (MN) are used as raw materials, and under the conditions that the inlet temperature is 70-100 DEG C, the volume space velocity is 1000-5000h <-1 >, the CO molar concentration is 10-40%, the CO / MN molar ratio is 1.0-3.0 and the reaction pressure is 0.05-2.0 Mpa, the raw materials pass through a Pd catalyst diluted by small balls with low specific surface area, large aperture and low acid content, the hot-spot temperature of a bed is lower than 125 DEG C, and the reaction is carried out for 1-2 hours, so that the methyl nitrite (MN) is obtained. According to the technical scheme, the problems are well solved, the selectivity of the dimethyl oxalate is larger than 98% in the long-time operation process, the space time yield of the dimethyl oxalate is larger than 750 g / (L.h), and the method can be used for industrial production of synthesizing the dimethyl oxalate through oxidative coupling of carbon monoxide.

The invention belongs to the technical field of electroplating, and discloses a dissimilar metal ion catalyzed electroplating solution as well as a preparation method and application thereof, and the electroplating solution comprises the following components by molar concentration: 0.02-0.25 mol / L of oxalic acid, 0.008-0.04 mol / L of citric acid and 0.04-0.1 mol / L of aluminum salt; the preparation method of the electroplating solution comprises the following steps: dissolving oxalic acid and citric acid in water to obtain a basic solution A; and aluminum salt is dissolved in the basic solution A, and the electroplating solution is obtained. The electroplating liquid does not have a replacement reaction with a to-be-plated part in the electroplating process of steel copper plating, so that the adhesion performance of a copper plating layer and the to-be-plated part of a steel product is improved; and the service life of the electroplating liquid is more than 10 times that of a common electroplating liquid, electrolyte such as main salt does not need to be supplemented, repeated use and subsequent treatment are facilitated, and the post-treatment cost of the electroplating liquid is reduced.

A method for cryopreservation and recovery of larch olgensis embryogenic callus relates to the biotechnology field of forest breeding, and comprises the following steps: selecting an embryogenic cell line induced by immature seeds of larch olgensis, and subculturing the embryogenic cell line for 3-5 days to obtain embryogenic callus as a standby material; carrying out gradient pre-culture at the molar concentrations of 0.2 mol / L and 0.4 mol / L in sequence, wherein the culture is carried out at each concentration for 20-48 hours; after pre-culture, putting the embryogenic callus into a freezing tube, and adding a sterile freezing protection solution; and putting the freezing pipe into a programmed cooling box for programmed cooling, and immediately putting the freezing pipe into a liquid nitrogen biological container for storage. The method disclosed by the invention is simple and convenient in operation steps and obvious in effect, the subculture age limit of the larix olgensis embryonic callus is slowed down, and relatively good cell viability and development potential in the initial stage of induction are maintained, so that the occurrence of variation is effectively reduced, manpower and material resources consumed by long-term subculture materials can be saved, and the production cost is reduced. The method is of great significance to theoretical and practical application research of larix olgensis.

The invention discloses celeste glaze fired in a non-reducing atmosphere and a preparation method of the celeste glaze. The celeste glaze provided by the invention is prepared from the following raw materials in percentage by mass: 56 to 60 percent of feldspar, 15 to 18 percent of quartz, 10 to 13 percent of calcite, 1 to 3 percent of talc, 5 to 8 percent of kaolin and 6 to 8 percent of celadon pigment. The main crystalline phase of the celadon pigment is zirconium silicate, vanadium ions and iron ions playing a coloring role are wrapped outside the zirconium silicate, the molar concentration of the vanadium ions is 2%-4%, and the molar concentration of the iron ions is 1%-3%. According to the method, the vanadium iron ion celadon pigment wrapped by the high-temperature pre-stabilized zirconium silicate is used as the coloring agent, and the celeste blue glazed porcelain is fired in the non-reducing atmosphere, so that the core problem existing in the traditional firing in the reducing atmosphere is successfully solved. And ferrovanadium ions in the coloring agent are stably wrapped in zirconium silicate crystals and are not influenced by the fluctuation of the firing atmosphere, so that the consistency of the glaze color of the same batch of celeste glaze is ensured. Regulation and control of the celeste glaze color are achieved through the adding amount of the celadon pigment, operation is easy, convenient and visual, and dependence on technical experience of operators is reduced.

The invention discloses a universal sample type nucleic acid releasing agent and application thereof. The nucleic acid releasing agent is prepared from the following components in molar concentration: 20 to 100 mM of Tris-HCl, 30 to 500 mM of sodium chloride, 30 to 200 mM of ammonium sulfate, 1 to 6 mM of EDTA (Ethylene Diamine Tetraacetic Acid), 1 to 8 mM of a reducing agent, 0.1 to 0.2 percent of sodium dodecyl sarcosinate, 0.1 to 3 mM of Surfactin, 5 to 30 percent of Chelex-100 and 5 to 15 percent of trehalose. According to the method, various samples can be mildly split, impurities such as impure proteins and lipids can be effectively removed, the complexity of nucleic acid samples is reduced, and the method is seamlessly jointed with subsequent PCR (Polymerase Chain Reaction); the kit has double effects of sample preservation and splitting decomposition, can strongly inhibit various nuclease, and can ensure the long-term storage stability of samples.

The invention relates to the field of chemical analysis and detection, in particular to a method for rapidly detecting the concentration of industrial concentrated acid based on neutralization reaction, which comprises the following steps: 1, theoretical calculation; converting molar concentration according to acid density and mass fraction; 2, accurately measuring the volume of target acid by using a pipette; 2, injecting 100-150ml of pure water into the triangular flask, and adding 3-5 drops of phenolphthalein; 3, slowly injecting an acid sample into the triangular flask, and slightly shaking and uniformly mixing; 4, adding 10.00 ml of NaOH solution by using the pipette, and oscillating for 10-20 seconds; 3, result interpretation: transparency and colorless: acid is excessive when the acid concentration reaches the standard, pH is less than or equal to 8.2 after neutralization, pink lasts for 20-30 seconds, and reinspection is needed when the acid concentration is insufficient and the pH is greater than or equal to 8.3. The method has the beneficial effects that 1, a reverse judgment method is adopted, namely the conventional end-point titration is replaced by fixed alkali amount, so that the detection time is shortened to 2 minutes; 2, safety design: pre-dilution reduces the risk of acid mist, and only a trace amount of raw acid is needed to avoid acid corrosion; 3, multi-acid adaptation: compatibility with detection of different types of concentrated acids is realized through pipetting volume adjustment;

Various embodiments may relate to a film. The film may include one or more types of nanostructures. The film may also include one or more types of ligands bonded to the one or more types of nanostructures. The one or more types of nanostructures may include neodymium (Nd) and ytterbium (Yb). A ratio of a molar concentration of neodymium (Nd) to a molar concentration of ytterbium (Yb) may be more than 1 : 1.

The invention discloses a norfloxacin-europium sensor array for identifying physiological phosphate and monitoring ATP (adenosine triphosphate) hydrolysis as well as a preparation method and application of the norfloxacin-europium sensor array. The sensor array comprises at least two sensing units with different norfloxacin-europium ion molar concentration ratios, the sensing unit is obtained by mixing and self-assembling a norfloxacin solution and a europium ion solution. Based on direct self-assembly of cheap norfloxacin (NF) and Eu < 3 + > ions, five physiologically crucial phosphates can be effectively distinguished, and ATP hydrolysis can be monitored. By adjusting the concentration of Eu < 3 + >, a multiple recognition mechanism is established, and target PPs can be completely distinguished with the accuracy of 100%.

The application provides a method for detecting PFAS based on a three-dimensional Ag / NiFe-LDHs surface enhanced Raman scattering substrate and ion pair extraction, and belongs to the technical field of PFAS detection, and comprises the following steps: first, a three-dimensional Ag / NiFe-LDHs SERS substrate is prepared; then, ion pair extraction-dissociation treatment is performed on a water sample to be measured to obtain a detection solution; finally, the substrate is immersed in the detection solution for adsorption, a spectrum is collected by using a Raman spectrometer, and semi-quantitative detection of PFAS in the water sample is realized according to the linear relationship between the characteristic peak intensity and the logarithm of the molar concentration of PFAS. The application realizes the synergistic application of the three-dimensional Ag / NiFe-LDHs SERS substrate and the ion pair extraction technology and the indirect detection of PFAS, improves the detection difficulty of weak PFAS Raman signals and difficult enrichment, improves the detection sensitivity and adaptability of PFAS in the water sample, and lays an application foundation for rapid monitoring of PFAS pollution in environmental water.

A method for separating an amine, said method comprising a separation step for separating an amine by chromatography using a stationary phase containing an oligosaccharide, a polysaccharide, and / or a derivative thereof, and a mobile phase containing one or more specific acids selected from the group consisting of oxalic acid, acetic acid, formic acid, and trifluoroacetic acid, one or more bases, and a solvent; when A is the value calculated by the following formula (1) for each specific acid contained in the mobile phase, SA is the total value of each A calculated by each specific acid, B is the value calculated by the following formula (2) for each base contained in the mobile phase, and SB is the total value of each B calculated by each base, SB / SA is 0.05-0.95. Formula (1): A = the number of elements of the specific acid * the molar concentration (mol / L) of the specific acid Formula (2): B = the number of elements of the base * the molar concentration (mol / L) of the base.