31results about How to "Elimination of Assay Effects" patented technology

The invention discloses a measurement method of a volatile organic compound in tobacco lining paper with high determination accuracy and good repeatability, which is suitable for simultaneously determining dozens of volatile organic compounds. The measurement method is as follows: taking fluorobenzene as an internal standard substance; using headspace gas chromatography for measuring the content of the volatile organic compound in the tobacco lining paper; wherein a detector in the headspace gas chromatography is a mass spectrometry detector. The measurement method takes the fluorobenzene as the internal standard substance, uses the headspace gas chromatography/mass spectrometry for measuring the content of the volatile organic compound in the tobacco lining paper, and has the following advantages that the fluorobenzene has stable chemical property and are very similar to determinand in every performance, and the peak time appears in the middle of 19 target VOCs to be detected; therefore, the fluorobenzene is the very suitable internal standard substance, can eliminate the influence of ground substance in the tobacco lining paper on the measurement, causes materials which can not or are difficult to peak to be measured, and has high measurement accuracy and few interference factors.

The invention relates to a method for using an atomic absorption spectrometry to detect the chromium ion content in the soil. The method has the specific steps that: firstly, the invention establishes a chromium standard concentration-absorbance curve, then, the soil sample is added with the distilled water for moisturization, after that, the concentrated sulfuric acid and the concentrated phosphoric acid are used for digestion, the heating is carried out till the soil sample emits the white smoke, then the concentrated nitric acid is added till a large amount of white smoke comes out and the soil sample turns white, and the digestion liquid turns yellow green; the digestion liquid is transferred to a standard volumetric flask, the pH value is regulated to 7, 1 percent of H2SO4 - 1 percent of Na2SO4 solution is added for dilution to a standard scale, the mixture is shaken evenly and placed still till the solution is clarified, the upper layer of clear solution is taken for the measurement of the absorbance under a wavelength of 213.9nm, and the chromium ion content in the soil sample can be obtained by comparison with the established standard curve in the step a. The measurement error of the chromium ion content in the soil sample which is measured by the method of the invention is within 3 percent.

The invention discloses a gas chromatograph and detection method for determining the total content of sulfides in natural gas. The gas chromatograph comprises a quartz capillary column, a hydrogen flame ionization detector, a temperature control unit and a sulfur chemiluminescence reactor which are successively connected, wherein the quartz capillary column is a fused silica capillary column with uncoated inner walls; and the gas chromatograph further comprises a processor which is connected with the sulfur chemiluminescence reactor and a display unit. The gas chromatograph and detection method provided by the invention eliminate influence of hydrocarbons on determination of sulfide content, are more accurate in testing and have a wider application scope.

The invention discloses a sample preprocessing device provided with an ion chromatograph and used for detecting anions and a use method. The device comprises a sample liquid suck-in pipe, an absorption liquid storage bottle, a flushing liquid storage bottle, a sample liquid peristaltic pump, an absorption liquid peristaltic pump, a flushing liquid injection pump, a dialysis pool, an anion exchanger, a six-way valve, an absorption liquid storage ring and the ion chromatograph. The sample liquid peristaltic pump, the absorption liquid peristaltic pump, the ion chromatograph and the flushing liquid injection pump are all connected with a computer terminal. During dialysis, sample liquid flows, and absorption liquid stops flowing; when absorption liquid is transferred to the absorption liquid storage ring, sample liquid stops flowing, and absorption liquid flows; when the six-way valve is switched, the flushing liquid injection pump flushes absorption liquid in the storage ring to an anion enrichment column in the ion chromatograph. The device has the advantages of online removing heavy metal ions, being low in measurement limit, high in sample adaptability, mild in condition and free of toxic reagents, being matched with the ion chromatograph, and being capable of measuring various anions in sewage or acrylic fiber solvent within 20 min.

The present invention discloses a pre-treatment method for a liquid desulfurizer solution of flue gas. The pre-treatment method comprises the following steps: heating and boiling the liquid desulfurizer solution of the flue gas, carrying out rapid evaporation to remove moisture in the liquid desulfurizer solution of the flue gas; under the boiling state, adopting ammonia water to adjust the pH value of the concentrated liquid desulfurizer solution of the flue gas to 7.5-9.5; continuously heating, boiling and volatilizing to remove the excess ammonia water to obtain the liquid desulfurizer solution of the flue gas, wherein the liquid desulfurizer solution is provided for the detection. At least the one selected from a gas chromatography-mass spectrometry combination method, a gas chromatography, a liquid chromatography, a liquid chromatography-mass spectrometry combination method is adopted to detect the pre-treated liquid desulfurizer solution of the flue gas.

The disclosed preparation method for an electrode chemical modified by O-carboxylmethychitose covalence bond comprises: dipping glass-carbon electrode into O-carboxylmethychitose-formic acid solution for modification, taking out to clean with formic acid and distilled water. This invention can improve detection sensitivity for DA, can eliminate effect of AA and UA, and has long lifetime.

The invention discloses a method for removing organic matters inside a sodium aluminate solution, and relates to a method for removing humic acid macromolecular organic matters inside the sodium aluminate solution with an adsorption method. The method is characterized by comprising the following steps: taking pseudo-boehmite as an adsorbent, mixing the sodium aluminate solution with the pseudo-boehmite, carrying out standing adsorption, and then carrying out liquid-solid separation to obtain a post-absorption liquid without the organic matters. According to the method disclosed by the invention, the humic acid macromolecular organic matters inside the sodium aluminate solution can be removed, and a filter liquor after adsorption filtration is used for accurately analyzing the content of sodium oxalate, so that the problem that the coexisting macromolecular organic matters are seriously disturbed is solved.

The invention discloses a method and a device for measuring rock capillary pressure in a reservoir temperature and pressure environment. The method comprises the following steps: 1) carrying out oil washing and salt washing on a rock core, and drying; 2) placing the rock core in a holder, applying confining pressure to the rock core by using fluorine oil, and heating the rock core; 3) carrying out a self-absorption experiment on the rock core, and monitoring the self-absorption behavior of the matrix part of the rock core by nuclear magnetic resonance; 4) after the self-absorption experiment is finished, enabling the rock core to be fully saturated with water, and acquiring the porosity of the rock core; 5) after the rock core is saturated with water, obtaining the permeability of the rock core by combining a constant flow method with a Darcy law; and 6) calculating to obtain a capillary pressure curve of the rock core in the reservoir temperature and pressure environment. The device is characterized in that the rock core is placed in a rubber sleeve, the rubber sleeve is fixed in a rock core holder, and the rock core holder is placed in a probe coil; and a nitrogen cylinder is sequentially connected with a displacement pump, a pressure sensor, a needle valve, a piston container and the needle valve. The capillary pressure curve of the core matrix part of the rock core under the reservoir temperature and pressure condition is obtained, and the method and the device are more suitable for being used on an oil reservoir development site.

The invention discloses an integrated recombiner comprising a dosing device and a mixing filter tank. The dosing device is arranged above the mixing filter tank. The dosing device comprises dosing pipes and an overflow tank. Three dosing pipes are provided, and the top end of each dosing pipe is connected to an overflow gate. The other end of each overflow gate leads to the interior of the overflow tank. The lower end of each dosing pipe is connected to a connecting pipe, and a liquid inlet pipe and a valve are arranged on each connecting pipe with the valve located below the liquid inlet pipe. The lower end of each connecting pipe is connected to a mixing liquid inlet pipe by means of a tee fitting, and a lower end of the mixing liquid inlet pipe is connected to the top end of the mixing filter tank. A glass sand core is arranged in the middle of the mixing filtering tank, and a filtrate discharge outlet is arranged in the bottom of the same. According to the integrated recombiner, dosing, mixing and filtering are integrated, and the structure is more compact and stable; a reagent and a water sample are fed together and come into sufficient contact with each other, thereby increasing the extent of the chemical reaction and improving the measurement sensitivity.

The invention relates to the field of analytical chemistry and particularly relates to a method for measuring aqueous formaldehyde in isoprene synthesizing industry by adopting olefine aldehyde method. With a formaldehyde-containing aqueous phase as a treatment object, the method is characterized by comprising the following steps: adding an alkaline solution into an aqueous phase to regulate the pH to alkalinity; separating the generated precipitate from aqueous phase to obtain a colorless clear solution; adding thymolphthalein into the colorless clear solution to turn the solution red, dropwise adding acid liquid to turn the solution colorless and neutral; adding a sodium sulfite solution into the neutral solution to turn the solution red, titrating with a sulfuric acid standard solution to turn the solution from red to colorless; and calculating the formaldehyde content in the aqueous phase according to consumption of the sulfuric acid standard solution. The method provided by the invention is simple and easy to implement, realizes an accurate result, eliminates influence of acid catalyst, multiple metal ions and C4 alcohol in the aqueous phase on formaldehyde measurement and is suitable for wide promotion and application.

The invention discloses a method for determining the content of ethylenediamine tetraacetic acid disodium salt in posaconazole injection, which comprises the following steps: (1) sample pretreatment:mixing posaconazole injection to be detected with a copper sulfate solution, adding a sodium hydroxide solution and water, performing mixing, performing filtering, and collecting the filtrate as a test solution; (2) elution: injecting the test solution into a chromatographic column, and pumping an eluent for elution; (3) detection: recording the peak area of the ethylenediamine tetraacetic acid disodium salt of the test solution; and (4) result calculation: comparing the test sample with the ethylenediamine tetraacetic acid disodium reference substance standard curve to obtain a detection result. According to the method disclosed by the invention, the residual sulfobutyl ether betadex sodium on the chromatographic column can be basically and completely eluted by adopting a gradient elutionhigh-proportion water phase, the influence of the sulfobutyl ether betadex sodium on the measurement of the disodium ethylene diamine tetraacetate is effectively eliminated, the error of a detectionresult is less than 1.5%, and the application requirements of related fields can be met.

The invention discloses an on-site automatic analysis method and instrument for inorganic arsenic form and phosphorus content in the underground water and relates to underground water quality analysis. The instrument is formed by sequentially connecting a sample introduction module, a reaction module and a detection module, wherein the sample introduction module is composed of an injection pump or a peristaltic pump, the reaction module is composed of a first reaction device and a second reaction device, and the detection module is composed of a light source, a flow cell and a detector. For an underground water sample containing trivalent arsenic, pentavalent arsenic and phosphate, light absorption values of phosphate and pentavalent arsenic, phosphate and pentavalent arsenic, and oxidized trivalent arsenic and phosphate are respectively obtained through direct determination, determination after oxidation by adding an oxidizing agent, and determination after reduction by adding a reducing agent, and concentrations of trivalent arsenic, pentavalent arsenic and phosphate are calculated by using an interpolation method; and simultaneous measurement of multiple parameters is realized. The method can be used for on-site analysis of inorganic arsenic form and phosphate content in underground water, and has advantages of simple operation, fast analysis speed, good reproducibility and high sensitivity.

The invention discloses a method for detecting the content of calcium sulfate in sintered desulfurization and denitrification ash, and mainly solves the technical problem that the calcium sulfate in the sintered desulfurization and denitrification ash cannot be accurately and efficiently detected in the prior art. According to the technical scheme, the method for detecting the content of calcium sulfate in the sintering desulfurization and denitrification ash comprises the following steps: 1) determining the content of total sulfur in the sintering desulfurization and denitrification ash; 2) measuring the content of sulfur in calcium sulfite in the sintered desulfurization and denitrification ash, adding 0.10-0.30 g of a desulfurization and denitrification ash sample into a beaker, then adding 100 mL of a dissolving solution into the beaker, and uniformly mixing the sample solution by ultrasonic oscillation; measuring the mass content M2 of sulfurous acid ions in the sample solution by using an ion chromatograph; and 3) calculating the mass content of calcium sulfate in the sintered desulfurization and denitrification ash. The method has the advantages of simplicity and convenience in operation, good precision, high accuracy and low detection cost.

The invention relates to the technical field of analytic chemistry, and especially relates to a method of measuring water phase C4 alcohols in the isoprene synthesis industry (olefin aldehyde method).The method is characterized in that a C4 alcohol containing water phase is taken as the processing object; an alkaline solution is added into the water phase to adjust the pH value to 8-14, precipitates are generated in the solution; through distillation, the C4 alcohol containing water phase is separated from a precipitating agent, excess alkalis, and soluble acidic salts generated during the process of acid-base neutralization; and finally gas chromatography is used to measure the accurate content of C4 alcohols in the water phase through an external standard method. The method is simple and easy to perform, the results are accurate, the influence of acid catalysts and multiple metal ions in the water phase on C4 alcohol measurement is eliminated, and the method is suitable for popularization and application.

The invention provides a method for directly measuring the content of nitrate in seawater and application of the method. According to the method, ammonia-free seawater is used as a blank solution and a diluted solution, so that the influence of background factors such as salinity in a seawater sample on determination is eliminated, meanwhile, scanning treatment is performed by adopting a second derivative ultraviolet spectrum method, the interference of other substances near an ultraviolet absorption peak of nitrate is eliminated, and the accuracy and selectivity of the method are effectively ensured. The method has the characteristics of good selectivity, wide linear range, high accuracy and good stability, can quickly and effectively detect the nitrate content in the seawater sample, and can be used for batch inspection. According to the method, no masking agent needs to be additionally added, the nitrate content in the sample can be directly measured after filtration, and the method has the advantages of being small in interference, easy to operate, high in speed, high in recovery rate, good in precision and the like and is suitable for rapidly and directly measuring the nitrate content in seawater, other saline water samples and some salt-containing industrial wastewater.