35 results about "Nitrosamine compound" patented technology

The invention discloses a method for removing nitrogenous disinfection byproducts in water on the basis of persulfate / light combination, and relates to a method for removing nitrogenous disinfection byproducts in water. The method for removing nitrogenous disinfection byproducts in water on the basis of persulfate / light combination comprises the following steps of: dosing persulfate in water including nitrogenous disinfection byproducts and then carrying out light irradiation. In the invention, persulfate or related composite chemicals are dosed in water and ultraviolet irradiation is utilized, so that abundant radicals are generated to attack the nitrogenous disinfection byproducts so as to realize denitrification and dehalogenation. The method provided by the invention has the advantages that the operation is simple, the effect is clear, the use is sage and no toxic byproduct is generated. By using the method, various nitrogenous disinfection byproducts such as acetonitrile, halogenated nitromethane, nitrosamine compounds, halogenated cyanogens, halogenated acetamide, halogenated pyrrole and organic chloramines can be thoroughly removed; and moreover, the method can be used for synchronously removing other organic matters and restraining and killing the microorganisms in the water.

The invention discloses a total-detection method of volatile N-nitrosamine compounds in foods. The total-detection method comprises the steps: sample extraction, qualitative analysis, quantitative determination, result analysis, and result conversion, wherein the sample extraction comprises distilling, extracting, concentrating and performing constant volume operation; the qualitative analysis is performed by adopting a gas chromatography-mass spectrometer; the quantitative determination is performed by adopting a gas chromatography. According to the total-detection method, the N-nitrosamine compounds in the foods are totally detected by adopting an NO and N2O dual-probe ion technology, and thus the species of the N-nitrosamine compounds can be accurately screened, non-N-nitrosamine compounds can be effectively eliminated, the false detection and the leak detection are prevented; nitrosamine compounds can be once distinguished from multiple volatile organic compounds, limited and less relevant nitrosamine compounds can be directly qualified and quantified, and thus the analysis time is greatly saved.

The invention relates to an LC-MC method used for determining NNK metabolites in liver microsomes and specifically to an LC-MC method used for analyzing and determining 4-(methyl nitroso)-1-(3-pyridyl)-1-butanone (NNK) metabolites in liver microsomes, which belongs to the field of biochemical analysis. The method provided in the invention mainly comprises the following steps: (1) preparation of an incubation system for liver microsomes; (2) sample treatment; (3) sample analysis and determination of NNK metabolites in the liver microsomes by using the LC-MC method. The invention has the following advantages of simple pre-treatment, a fast analysis speed, good selectivity, high detection sensitivity and capacity of analyzing and comparing the metabolism of NNK in different kinds of liver microsomes, can lay a methodological foundation for further research on in-vivo and in-vitro metabolism of NNK and other nitrosamine compounds and has critical significance.

The invention discloses a series solid-phase extraction (SPE) method for nitrosamine compounds in drinking water. The method comprises the following steps of: 1) manufacture of a series solid-phase extraction column: assembling 200mg / 6ml of Oasis hydrophile-lipophile balance (HLB) small column and 2g / 6ml of Coconutcharcoal activated carbon SPE small column up and down in order by a connecting head to form the series solid-phase extraction column, and installing the series solid-phase extraction column onto a solid-phase extraction device; and 2) solid-phase extraction of the nitrosamine compounds: activating by using methanol and dichloromethane, treating water sample by the column, drying by using nitrogen flow, eluting by dichloromethane and carrying out nitrogen blowing concentration. The SPE method has higher recovery rate for nine nitrosamine compounds in the drinking water, is good in stability as well as simple and convenient in operation, and solves the problem that the existing SPE method only can be used for extracting one or more nitrosamine compound(s) with similar polarity, thus providing technical support for accurately measuring the concentration of multiple nitrosamine disinfection by-products in the drinking water.

The invention discloses a method for purifying pendimethalin, which comprises the following steps of: adding coarse product of pendimethalin, thiocyanate and hydrochloric acid into a reaction container according to a mass ratio of 7-10:1:3-5; performing reflux reaction at the temperature of between 75 and 81 DEG C for 6 to 15 hours under normal pressure, adding the thiocyanate again in the reaction process for continuous reaction until the content of N-nitrosamine compound is less than 10ppm, and taking an oil layer after the reaction is finished; and washing the oil layer with water, alkali and water in turn and controlling the temperature to between 60 and 90 DEG C under the vacuum condition for removing a solvent so as to obtain the pendimethalin. The method for purifying the pendimethalin has the advantages that: due to the existence of the aid thiocyanate, the speed of the reaction for removing the N-nitrosamine compound is high, and the content of the N-nitrosamine compound is less than 20ppm; because the reaction temperature is controlled at the reflux temperature, the method does not need to be operated under the pressure condition, and can reduce the operating difficulty and equipment requirement and improve the operating safety.

The invention discloses a detection method of nitrosamine impurities in candesartan cilexetil. The method comprises the following steps of: S1, preparing a solution: respectively preparing a test solution and a standard curve solution; and S2, detecting: detecting and analyzing the test solution and the standard curve solution in the step S1 by adopting liquid chromatography and mass spectrometry.According to the detection method disclosed by the invention, nitrosamine compounds in the candesartan cilexetil can be more comprehensively detected, and simultaneous detection of seven nitrosaminecompounds can be realized on the premise of adopting one ion source, so that the quality and medication safety of the candesartan cilexetil are ensured. The detection limit of the detection method fordetecting the nitrosamine compounds in the candesartan cilexetil can reach a trace level; the detection method disclosed by the invention has good system adaptability, specificity, quantification limit and detection limit, linearity and range, accuracy, precision, durability and solution stability on detection of seven nitrosamines in the candesartan cilexetil.

The invention relates to an analysis method for detecting more than 9 nitrosamine compounds in water. The nitrosamine compounds comprise N-nitrosodimethylamine, N-Nitroso-ethyl methylamine, N-Nitrosodiethylamine, N-nitrosodipropylamine, N-nitrosodibutylamine, N-nitrosopyrrolidine, N-nitrosopiperidine, N-nitrosomorpholine and N-nitrosodiphenylamine. The analysis method comprises the following steps of: extracting a water sample to be detected by adopting solid phase micro-extraction; and determining the nitrosamine compounds by adopting a gas chromatography tandem mass spectrometry (GC-MS / MS). The method provided by the invention achieves rapid, convenient and sensitive determination of the content of various nitrosamine compounds in the water sample, and has the advantages of the high analysis efficiency and the better popularization prospect.

The invention discloses difluoroethyl-containing nitrosamine compounds and a preparation method thereof. A series of difluoroethyl-containing nitrosamine derivatives are obtained by taking carboxylicacid as a catalyst and carrying out an aza-Michael addition / nitrosation tandem reaction on three components, i.e., difluoroethylamine, tert-butyl nitrite and 1-aryl 2-nitroethylene at room temperaturein absence of other organic solvents. Molecular skeletons of the compounds contain potentially bioactive difluoroethyl and nitrosamine groups, thus establishing a material basis for drug discovery and druggability evaluation, and having an important application value. The preparation method provided by the invention adopts the easy-to-obtain raw materials, does not need an additional organic solvent, and has the advantages of mild reaction conditions, simple operation, high yield and good substrate universality.

A curable organopolysiloxane composition comprises: (A) an alkenyl group-containing organopolysiloxane; (B) a compound having at least two thiol groups in a molecule; (C) an azo compound and / or an organic peroxide; and (D) at least one type of compound selected from the group consisting of quinone compounds, compounds having one or two aromatic hydroxyl groups in a molecule, compounds having one thiol group in a molecule, nitrosamine compounds, hydroxylamine compounds, and phenothiazine compounds. The curable organopolysiloxane composition can be quickly cured even at a relatively low temperature (e.g. of 80° C. or lower) to form a cured film with excellent adhesion to an object to be coated.

The invention relates to a 1, 4-nitrosation-N-nitrosamine intermediate (I) compound in the synthesis of alprazolam, a preparation method and application thereof to the preparation of alprazolam. 7-chloro-5-phenylbenzodiazepinone is taken as an initial raw material, and the alprazolam is obtained by the synthesis through certain processes such as condensation ring-closure after a methylamination reaction and an N-nitrosation reaction. Other benzodiazepine derivatives can be synthesized through a 1, 4-nitrosation-N-nitrosamine intermediate obtained by the synthesis. The method has the advantages of unique process, steady product quality, mild process conditions, easy control, and high yield, and can control lower production cost and reduce environmental pollution.

The invention discloses a method for determining the content of volatile N-nitrosamine compounds in plasma by gas chromatography-mass spectrometry. The method comprises the following steps: (1) centrifuging a blood sample to separate out plasma, adding dichloromethane and an NDPA-D14 internal standard solution into the plasma, carrying out whirling in a vortex mixer, mixing uniformly and carryingout ultrasonic extraction, re-centrifuging after the ultrasonic extraction, and feeding lower layer liquid; and (2) carrying out determination by the gas chromatography-mass spectrometry. Through theadoption of the method for determining the content of the volatile N-nitrosamine compounds in the plasma by the gas chromatography-mass spectrometry disclosed by the invention, nine volatile N-nitrosamine compounds in the human plasma can be determined at the same time; the detection limits and quantification limits of the nine volatile N-nitrosamine compounds are 0.01-2.14ng / mL and 0.02-7.14ng / mLrespectively; the study of the load levels of the N-nitrosamine compounds in the human body is facilitated; and a basis is laid for the study of the influence of N-nitrosamine compound exposure on the human health.

The invention relates to a bitter melon extract and application of the extract in reduction of an N-nitrosamine compound in cigarette smoke. Specifically, a preparation method of the bitter melon extract comprises the following steps that 1, bitter melons are subjected to ultrasonic extraction in an alcohols solvent, and filtration and filtrate collection are performed; 2, the filtrate collected in the step 1 is concentrated and extracted, an organic phase is collected, dried and concentrated to obtain the bitter melon extract. The content of the nitrosamine compound in a main smoke flow can be reduced, the bitter melon extract can coordinate with the cigarette smoke to improve the sweet aftertaste of the smoke.

The invention provides a method for detecting nitrosamine compounds in higenamine hydrochloride, which comprises the following steps: selecting octadecylsilane chemically bonded silica as a filler, and formic acid aqueous solution and methanol as mobile phases, so that when the higenamine hydrochloride containing NDMA, NDEA and other impurities is separated through liquid chromatography, the higenamine hydrochloride and other impurities cannot cause interference on the dissociation selectivity of the chromatographic column on target objects NDMA and NDEA in the dissociation process of NDMA and NDEA molecules under the conditions. The number of theoretical plates of an NDMA peak in the method is not smaller than 6014, the number of theoretical plates of an NDEA peak in the method is not smaller than 120325, symmetry factors are not larger than 2.0, and the recovery rate of the detection method ranges from 85% to 102%. According to the method, the system applicability, specificity, precision, quantitation limit, detection limit, linearity and range all meet the requirements, the separation effect is good, operation detection is achieved, and the method sensitivity is high.

The invention relates to the technical field of food pickling, in particular to a pickling method of nutritional flavoring garlic. The pickling method of the nutritional flavoring garlic is simple, and low in cost, a garlic pickled product prepared by the method is safe, healthy, rich in nutrition and convenient to eat, contains no harmful additives, avoids the generation of ammonium nitrite, is rich in taste, and has pure natural fermentation fragrance; the maca enzyme and the fermenting agent contain various active protein small peptides in the fermentation process, and the maca enzyme can also alleviate the physical fatigue and improve the immunity; moreover, the fermenting agent can promote the digestion while suppressing the generation of nitrosamine compounds.

The invention provides a preparation method and application of N-nitrosamine toxicant composite imprinted sheet. (1) preparation of supporting materials: chromium nitrate nonahydrate and terephthalicacid are weighed by mole ratio and added into 80mL deionized water, then a small amount of hydrofluoric acid is added to prepare supporting materials; (2) preparation of N-nitrosamine imprinting material: weighing the supporting material and reacting with deionized water-DMSO to obtain N-nitrosamine imprinting material; (3) tablet pressing: weighing the above-mentioned N-nitrosamine solid powder and pressing it into a circular sheet with a special mold. The imprinted sheet of the invention can be arranged in a cigarette filter, and when the cigarette is burned and sucked, the imprinted sheet is used for selectively adsorbing N-Nitrosamine toxicant, selective reduction of N-nitrosamine concentration 30-60%, and that imprinted sheet can be reused after being recovered and treated, thereby reduce the production cost.

The invention discloses a synthesis method of a nitrosation product of secondary amine, which uses economic and nontoxic metal nitrate as a nitro source through electrocatalytic free radical couplingreaction to carry out non-oxidation N-nitrosation reaction on an N-H bond of morpholine, and the reaction system is suitable for various common secondary amines. According to the method, an electro-catalysis mode is adopted, various cheap metal nitrates are taken as nitrate sources, a target product is synthesized by adopting a one-step method, the reaction process is simple, the substrate universality is good, the yield of the generated nitrosamine compound is high, and a green N-N single bond construction method is realized.

The invention belongs to the technical field of cigarette production. The invention particularly discloses a cigarette flavor which comprises corn stigma extract and proline, the invention discloses an extraction method, According to the extracted corn stigma extract, various bioactive substances in corn stigma are extracted, flavonoids, phenols and other substances in the corn stigma have oxidation resistance, nitrosation reaction can be inhibited, the synthesis of N-nitrosamine compounds can be blocked, nitrosamine compounds or other precursors in smoke are subjected to physical adsorption and chemical action, and harm to tobacco products can be reduced.

This application belongs to the technical field of drug analysis. The application provides a method for detecting nitrosamine impurities in biapenem, comprising: taking the test product and adding an internal standard methanol solution to dissolve, then adding a mixed solvent and mixing evenly to obtain a sample solution; mixing the sample solution and The reference substance solution was respectively injected into a liquid chromatography tandem mass spectrometer, and the content of nitrosamine impurities was detected by the internal standard method; wherein, the composition of the mixed solvent included methanol, formic acid and water. This application develops the method according to the characteristics of nitrosamine compounds, which can effectively reduce the influence of the matrix effect and prevent the analyte from being inhibited. The detection method of this application was verified from the aspects of specificity, linearity and range, detection limit, quantitation limit, accuracy, and stability, and confirmed that the method is suitable for the simultaneous determination of the contents of NDEA, EIPNA, and DIPNA in biapenem.

The invention relates to the technical field of food preservation, in particular to a composition for inhibiting generation of nitrosamine by combining plant essential oil with strain volatile substances and a preparation method of the composition. The composition for inhibiting the generation of nitrosamine by combining the plant essential oil with the strain volatile substance comprises the plant essential oil and the strain volatile substance, the volatile substance of the strain comprises freeze-dried powder of a liquid culture of bacillus provenensis and stenotrophomonas rhizophila for 48 hours. Volatile aroma components of the grapefruit essential oil and the cinnamon essential oil and volatile substances of freeze-dried powder of 48-hour liquid cultures of the bacillus provenensis and the stenotrophomonas rhizophila are utilized, so that the activity of microorganisms can be inhibited through diffusion of the volatile substances of the raw materials in the storage process of the cooked meat product; the combination process of secondary amine and nitrous acid is blocked, so that the generation of nitrosamine compounds is inhibited in the storage process, and the generation of nitrosamine substances in the cooked meat product is reduced.

The invention discloses a device for extracting a nitrosamine type compound and in particular relates to the field of laboratory apparatuses. The device comprises a sample solution containing bottle,a solvent containing bottle, a condensation device for condensing fractions, a liquid distribution device for standing and liquid distribution of the fractions, a first ventilation pipe communicated with the solvent containing bottle, a second ventilation pipe communicated with the sample solution containing bottle and a flow promoting device for accelerating gas in the first ventilation pipe or the second ventilation pipe to flow. The device disclosed by the invention has the advantage that the flowing of the fractions or a gas-state solvent can be accelerated in a pipeline so that the extraction efficiency is improved.

The invention belongs to the technical field of cigarette production, and specifically discloses a cigarette spice, including corn silk extract and proline, the extraction method used in the present invention, the extracted corn silk extract, and various bioactive substances in corn silk Extracted, the flavonoids, phenols and other substances in it have antioxidant properties, can inhibit the nitrosation reaction and block the synthesis of N-nitrosamine compounds, and affect the occurrence of nitrosamine compounds or other precursors in the smoke. Physical adsorption and chemical action can reduce the harm of tobacco products.

The invention belongs to the technical field of rubber synthesis, and is a method for synthesizing butyl rubber with a narrow molecular weight distribution. The solvent used in the method is a solvent formed by mixing halogenated alkanes and saturated alkanes with carbon four to ten carbons, wherein the volume ratio of the content of halogenated alkanes is 1 %~55%; the composition of the main catalyst used is R-Al-Cl 2 :R 2 -Al-Cl 1 : vanadyl trihalide, add a certain proportion of water in the catalyzer; Add benzopyrene and / or nitrosamine compound again in the prepared main catalyst, form co-initiator; Main initiator is R-Al-Cl 2 and R 2 -Al-Cl 1 . The advantages of the present invention: the catalytic system is a homogeneous system, which is convenient for feeding; by adding a small amount of water, a stable complex initiation system is formed; the method can solve the problem that the molecular weight of butyl rubber decreases with the increase of temperature, and the obtained butyl The number average absolute molecular weight of the rubber is 2,000 to 550,000, and the molecular weight distribution is between 1.1 and 2.0.

The invention belongs to the technical field of rubber synthesis and provides a narrow molecular weight distribution butyl rubber synthesis method. The method utilizes a haloalkane-C4-10 saturated alkane mixed solvent, the content of haloalkane is in a range of 1-55% by volume, a used main catalyst comprises R-Al-Cl2, R2-Al-Cl1 and vanadium trihalide oxide, water is added into the catalyst according to a certain ratio, benzopyrene and / or nitrosamine compound is added into the main catalyst so that an initiator aid is formed and a main initiator comprises R-Al-Cl2 and R2-Al-Cl1. The catalysis system is a homogeneous system and is convenient for charging. Through use of a trace amount of water, a stable complex initiation system is formed. The method solves the problem that butyl rubber molecular weight is reduced along with temperature increasing. The butyl rubber has number-average absolute molecular weight of 2000-550000 and molecular weight distribution of 1.1-2.0.

The invention discloses a method for purifying pendimethalin, which comprises the following steps of: adding coarse product of pendimethalin, thiocyanate and hydrochloric acid into a reaction container according to a mass ratio of 7-10:1:3-5; performing reflux reaction at the temperature of between 75 and 81 DEG C for 6 to 15 hours under normal pressure, adding the thiocyanate again in the reaction process for continuous reaction until the content of N-nitrosamine compound is less than 10ppm, and taking an oil layer after the reaction is finished; and washing the oil layer with water, alkali and water in turn and controlling the temperature to between 60 and 90 DEG C under the vacuum condition for removing a solvent so as to obtain the pendimethalin. The method for purifying the pendimethalin has the advantages that: due to the existence of the aid thiocyanate, the speed of the reaction for removing the N-nitrosamine compound is high, and the content of the N-nitrosamine compound is less than 20ppm; because the reaction temperature is controlled at the reflux temperature, the method does not need to be operated under the pressure condition, and can reduce the operating difficulty and equipment requirement and improve the operating safety.

The invention provides a new N-nitrosamine compound imprinted polymer sheet and its preparation method and application. (1) Preparation of supporting material: Weigh chromium nitrate nonahydrate and terephthalic acid in molar ratio, add Add a small amount of hydrofluoric acid to 80mL deionized water, and then add a small amount of hydrofluoric acid to prepare the support material; (2) Preparation of N-nitrosamine imprinting material: Weigh the support material, deionized water-DMSO and other steps to prepare N-nitrosamine Nitrosamine imprinted material; (3) Tablet forming: Weigh the above-mentioned N-nitrosamine solid powder and press it into a circular sheet with a special mold. The imprinted sheet of the present invention can be arranged in a cigarette filter, and is used for selectively adsorbing N-nitrosamine poisons in mainstream smoke and selectively reducing N-nitrosamines in mainstream smoke when cigarettes are burned and smoked. The compound concentration is 30-60%, and the imprinted flakes can be reused after recycling, reducing production costs.

The invention discloses a method used for detecting content of nitrosamines in food. The method comprises following steps: food is smashed, and 15 to 25g of an obtained sample is added into a dichloromethane solution; distillation is carried out, 10 to 20ml of acetone is added for ultrasonic extraction, and an obtained extract is collected; the extract is subjected to refrigeration centrifugation,8 to 15ml of an obtained supernatant is transformed into a separating funnel, 3 to 8ml of dichloromethane is adopted for extraction of the supernatant, an obtained dichloromethane layer solution is collected, and is subjected to condensation until the volume of an obtained concentrated solution is reduced to 1ml; the concentrated solution is subjected to filtering using a filter membrane so as toobtain a solution to be measured; gas chromatography-thermal energy analyzer is adopted to measure the solution to be measured, wherein a chromatographic column with medium polarity is adopted in gaschromatography, helium is taken as the carrying gas, and temperature programming is adopted. The principles of the method are reliable; experiment operation is simple; utilization of the high sensitivity of chromatography and mass spectrum is realized, measuring precision and accuracy are ensured, separation of nitrosamine compounds from many volatile organic components in one time is realized, and analysis time and testing cost are saved greatly.