49results about How to "Optimize separation conditions" patented technology

The invention discloses a method for measuring contents of methanol, sec-butyl alcohol, sesamol and musk xylene in an additive for cigarettes. The method comprises the following steps of: preparing an internal standard solution, preparing a standard solution, preparing a sample solution, and performing quantitative and qualitative analysis on the methanol, sec-butyl alcohol, sesamol and musk xylene by employing gas chromatograph-mass spectrometer (GC/MS). By utilizing the GC/MS, the contents of methanol, sec-butyl alcohol, sesamol and musk xylene in the additive for the cigarettes can be directly measured, and the method has the advantages of easiness and convenience in operation, high rapidness, high accuracy, high sensitivity and high repeatability.

The invention discloses a method for detecting seven prohibited compounds in flavors and fragrances. The seven prohibited compounds are methanol, sec-butyl alcohol, safrole, imidazole, coumarin, musk xylene and sesamol. The detection method can accurately and rapidly detect the contents of the seven prohibited compounds in flavors and fragrances, is suitable for quality safety control of fragrance raw liquid and auxiliary solvents in the industries such as food, daily-use chemical industry, tobacco and pharmacy, and the has the characteristics of simple operation, rapidness, accuracy, good repeatability, high sensitivity and the like.

The invention provides a method for detecting retinol and a precursor thereof. The method comprises the following steps: 1, extracting retinol and/or the precursor thereof from a sample; 2, separating retinol and/or the precursor thereof through HPLC; and 3, carrying out MS/MS quantitative detection, wherein the sample is a dry blood spot card sample, and an extractant adopted in the invention is trichloromethane. A filter paper card is adopted as a carrier to adsorb a tiny amount of blood in order to make the dry blood stop card, so the difficulties of much blood induced by venous blood collection, bad population compliance, death induced by animal model blood drawing, and inconvenient long-distance conveying of samples in previous serum collection and detection process are overcome. The method has the advantages of small matrix effect, good linear relation of analysis in the concentration range of a standard curve, low detection limit, high sensitivity, good accuracy and high precision, is related with the result of detection of retinol in serum through HPLC, allows the contents of the retinol and the precursor thereof in the sample to be simultaneously and synchronously analyzed, and provides a method for comprehensive assessment of the in vivo retinol level.

Floating circulation oil collector and circulation separation method are suitable for on-site treatment of oily sewage in oil exploration, collection, storage and transportation, processing and other petrochemical processes; pre-treatment of oily sewage treatment plants, replacing oil separation, air flotation and other mixing with different specific gravity Separation and removal of liquids. The oil collection tank is connected with the ring pipe, and the lower part is provided with a support rod; the oil collection bucket in the oil collection ring at the upper part of the oil collection tank is connected with the oil outlet pipe; the water outlet of the oil collection tank at the lower part of the oil collection tank is connected with the peripheral pumping equipment; the lower part of the container is provided with a water outlet pipe; An oil collection tank buoy is arranged on the outer surface of the oil collection tank; a buoy, a ring pipe buoy and a water injection pipe are arranged on the ring pipe; the water inlet pipe system is connected with the ring pipe; the ring pipe matches the pulley on the guide rod. The circulation separation method is: the oily sewage enters the water inlet pipe system from the water inlet, so that the floating oil on the liquid surface flows to the oil collection tank and the oil collection bucket, and is discharged through the oil outlet pipe; the separated clean water is discharged from the water outlet pipe; the water outlet and The peripheral pumping equipment is connected to form a circulation loop and reciprocate. It has the advantages of saving energy and reducing land occupation.

The invention relates to a method for rapidly separating lentinan and belongs to the technical field of biomacromolecule separation and purification, in particular to a method for rapidly separating lentinan using an ionic liquid two-aqueous phase system composed of [Bmim]Cl/K3PO4. The method is green, highly-efficient and rapid, is suitable for large-scale industrial production of active polysaccharides, reduces the production cost by recycling the ionic liquid, and can be widely applied to the separation and purification of fungal polysaccharides.

The invention relates to a method for detecting yeast beta-glucan in milk or a milk product. The method comprises 1, pretreatment: carrying out enzymolysis on milk or a milk product through a neutral protease or an alkaline protease, carrying out centrifugation on the enzymolysis product, cleaning the precipitates obtained through centrifugation through pure water or deionized water, adding an monobasic acid into the precipitates and carrying out heating hydrolysis, and 2, analysis: determining glucose content of the pretreatment product through ion chromatography and calculating yeast beta-glucan content of the milk or milk product.

The invention belongs to the field of analytical chemistry and the technical field of determination of pesticide residues, particularly relates to a method for splitting and measuring enantiomer of achiral pesticide benalaxyl through the ultra-performance convergence chromatography-tandem mass-spectrometric technique, and relates to a method for splitting and quantifying raceme of the chiral pesticide. The method uses a QuEChERs method to extract benalaxyl in tobacco, cereals and dried fruits, and the enantiomer of the chiral pesticide benalaxyl is detected through the combination of convergence chromatographic chiral stationary phase and triple quadrupole tandem mass spectrum. The convergence chromatography is used for the first time to rapidly chirally separate the benalaxyl, and the sensitivity is high. The supercritical CO2 is taken as a mobile phase, a large number of organic solvents are saved in use, and the method is green and environmentally friendly.

The invention relates to a method for detecting the effect of PQQ on lactic acid by combining HPLC with UPLC-MS and belongs to the technical field of bioanalysis. The method provided by the invention adopts an UPLC method for studying reaction between PQQ and lactic acid, and separation conditions are optimized, so that separation of the PQQ from multiple reaction products is achieved; and qualitative analysis is carried out on the reaction products by adopting UPLC-MS. The method provided by the invention firstly studies the reaction behavior of the PQQ and the lactic acid, three products are found in reaction liquid, and quasi-molecular ions [M+H]<+> are 403, 475 and 547 respectively. Esterification reaction is respectively carried out on the PQQ as well as monomolecular lactic acid, dimolecular lactic acid and trimolecular lactic acid, and products PQQLa1, PQQLa2 and PQQLa3 are obtained respectively. Peak areas of products obtained by different reaction times show that the PQQLa1 exists mainly, and products after esterification enter extracellular fluid by passing a blood brain barrier, so that the lactic acid content of the extracellular fluid is reduced. The method provided by the invention has extremely important research values on a neuroprotective mechanism of the PQQ, especially in the aspect of disease study related to senility.

The invention discloses on-site treatment equipment for defective cigarettes. The on-site treatment equipment for the defective cigarettes comprises a rack box body, wherein a carding device, a conveying device, a slitting device and a screening device are arranged in the rack box body; the conveying device is positioned below the carding device, and the discharge end of the conveying device extends to the feeding end of the slitting device; and the discharge end of the slitting device corresponds to the feed inlet of the sieving device. The on-site treatment equipment for the defective cigarettes has the advantages that the functions are highly integrated, the on-site treatment equipment is small and exquisite, a single piece of equipment is in butt joint with a cigarette making machine,the original defective cigarette collecting box is replaced, the defective cigarettes can be treated in situ, and the on-site treatment equipment for the defective cigarettes is simple and reliable touse and operate.

The invention belongs to the technical field of biological pharmacy, and particularly relates to a synthesis method of enzyme-catalyzed (1S, 5R)-bicyclolactone. The method comprises the following steps of preparing engineering bacteria containing Bayer-Villiger monooxidase; preparing a resting cell suspension of the engineering bacteria, ultrasonically crushing or pressurizing and crushing to obtain a supernatant containing Bayer-Villiger monooxidase cells, mixing the supernatant with a substrate racemic substituted bicyclo [3.2.0]-hept-2-ene-6-one, a hydrogen donor and a cofactor, and carrying out asymmetric Bayer-Villiger oxidation to prepare (1S, 5R)-bicyclolactone, wherein an amino acid sequence of the Bayer-Villiger oxidase is shown as SEQ ID NO. 1. According to the method, racemic substituted bicyclo [3.2.0]-hept-2-ene-6-one (II) can be catalyzed to generate chiral (1S, 5R)-bicyclolactone, the used engineering bacteria is convenient and easy to obtain, and the product is convenient to separate and high in enantioselectivity.

The invention relates to a UHPLC-ICPMS online bromide and iodide species determination analysis method. The method uses HPLC and ICPMS technologies in a combined way, and comprises the following steps of selecting UHPLC and an ICP-MS instrument; performing ICP-MS instrument parameter optimization; configuring a separation column and a protection column of the UHPLC; optimizing the separation conditions; connecting a pipeline of the UHPLC and the ICP-MS instrument; performing leakage inspection; performing pretreatment on the sample to be tested; determining the separation time through an experiment chromatography separation diagram; measuring the standard curve, the detection limit and the precision; performing sign adding recovery and practical sample determination. The method has the advantages that the separation time is short; the linear relationship is good; the detection limit is low; the sign adding recovery rate is high; the precision is high. The method can be used for the trace analysis of the bromide and iodide species in samples of environment and the like; the fast separation and accurate determination can be realized; the accurate determination of the sample can be completed in 5 minutes.

The invention provides a method for detecting content of methanol in tobacco flavor. The method comprises the following steps: preparation of an internal standard solution, preparation of a standard solution, preparation of a sample solution, and detection of methanol content by gas chromatography. The gas chromatography is used for direct detection of the content of methanol in tobacco flavor, so that methanol and other interference components can be effectively separated; and the method has the advantages of simple operation, rapid, accuracy, high sensitivity, and good repeatability.

The invention provides a construction method of a lindley eupatorium herb formula granule fingerprint spectrum, a standard fingerprint spectrum of the lindley eupatorium herb formula granule and application of the standard fingerprint spectrum, and belongs to the technical field of medicine detection.The construction method comprises the steps that a test solution, a reference medicinal material solution and a reference substance solution are prepared, acetonitrile (A) and a 0.1-0.3 wt% phosphoric acid aqueous solution (B) are jointly used as mobile phases, and the standard fingerprint spectrum of the lindley eupatorium herb formula granule is obtained. Performing high performance liquid chromatography detection to obtain a fingerprint spectrum of the lindley eupatorium herb formula granules; the standard fingerprint spectrum of the lindley eupatorium herb formula granules is obtained by using the construction method, and the standard fingerprint spectrum is used for quality evaluation or control in the whole process of research/development/production/clinical application of the lindley eupatorium herb formula granules. According to the method for constructing the fingerprint spectrum of the lindley eupatorium herb formula granules, main medicinal material components in the lindley eupatorium herb formula granules can be detected only through high performance liquid chromatography, and the quality condition of the lindley eupatorium herb formula granules can be comprehensively reflected.

The invention discloses a method for forecasting a leading chromatographic peak shape under the multi-order programmed temperature condition. The method mainly comprises the followings: evaluating a chromatographic retention factor value under different temperatures according to a virtual dead time; searching out a peak shape parameter PSP under the constant temperature condition through a computer program according to nonlinear plate theory; establishing the functional relations between the retention factor as well as the peak shape parameter and the temperature through the regression analysis based on the retention factor and the peak shape parameter of a to-be-detected compound under different constant temperatures; and setting the temperature program, obtaining the forecasted leading chromatographic peak shape through calculation of the computer and comparing with a testing peak shape obtained under the same programmed temperature condition. The invention provides a vital basis for qualification of the type of chromatographic peak shape such as the leading chromatographic peak, optimizes the chromatographic fractionation condition, and provides a new way for accurate quantification of overlapping chromatographic peak common in a laboratory at the same time; and furthermore, the method is widely applicable, and has high forecasting accuracy.

The invention provides a tetrafluoroethylene (TFE) refining method, which comprises the following steps of 1, conveying TFE production pyrolysis gas into a first separation tower to be separated; recovering TFE from tower top gas of the first separation tower; introducing coarse gas of the first separation tower into a rectification tower after the coarse gas of the first separation tower is exhausted from the middle part of the first separation tower; enabling tower kettle liquid of the first separation tower to enter a heavy ingredient recovery system; 2, after the coarse gas of the first separation tower enters the rectification tower to be subjected to rectification, obtaining TEF monomers from the tower top of the rectification tower; enabling tower kettle liquid of the rectification to enter a second separation tower. The TFE refining method has the beneficial effects that the first separation tower middle part side line production scheme is used; light ingredients are produced from the tower top of the first separation tower and enter a TFE recovery system for recovering TFE and then discharging light ingredients; middle part side line TFE coarse gas enters the rectification tower, and the TFE monomers with the purity being greater than 99.9999 percent can be obtained from the tower top of the rectification tower.