116results about How to "Avoid matrix interference" patented technology

The invention discloses a Pyrifluquinazon residue determination method. The method comprises the steps of homogenously extracting residual Pyrifluquinazon in a sample through acetonitrile or 1% acetic acid acetonitrile, dispersing and purifying an extracting solution through ethylenediamine-N-propyl silicane (PSA), octadecyl silicane bonded phase (C18) and graphitized carbon (Carb) substrate, implementing liquid chromatogram-tandem mass spectrum (LC-MS / MS) detection, establishing a correction standard curve through a blank matrix solution dilution standard, and quantifying through an external standard method. According to the determination method disclosed by the invention, average recovery rate is 85.3-92.0%, average relative standard deviation (RSD) is 3.5-6.1% and detection limit is lower than 0.38 mu g / kg, and the method has the advantages of simplicity and rapidness in operation, high sensitivity, good repeatability, and accuracy in qualitative and quantitative determination. The method can satisfy technical requirements of Korea, Japan, European Union and other countries on corresponding product safety detection, and provide powerful technical support for guaranteeing food safety of Chinese people and healthy development of export trade.

The invention discloses a method for measuring aromatic amine in plasticine, which comprises the following steps of: cutting the plasticine into small pieces, and performing ultrasonic extraction on the small plasticine pieces by using methanol, ethanol, isopropanol or acetonitrile to obtain extracting solution; removing organic solvent in the extracting solution, and adding sodium hyposulfite solution to perform a reduction reaction at the temperature of between 60 and 80 DEG C; after the reaction is finished, regulating the pH value of reaction solution to be between 10 and 12, purifying bya solid phase extraction column, and eluting to obtain eluent; and allowing the eluent to enter a gas chromatograph-mass spectrometer to measure the aromatic amine. The method for measuring the aromatic amine in the plasticine fills the blank of the technology, and the problem of matrix interference caused by other ingredients in the plasticine is solved effectively; and due to the adoption of a common detection device, the method is easy to popularize.

The invention discloses a GC-NCI-MS determination method for determining residual amount of chlorantraniliprole, which is mainly used for determining content of residual chlorantraniliprole in complex matrix food agricultural products such as cereal grains and animal derived foods. The GC-NCI-MS determination method comprises the following steps: extracting the residual chlorantraniliprole in a sample by adopting acetonitrile or acetonitrile solution containing 1% of acetic acid in a homogenizing manner; purifying and concentrating by adopting a C18 / PSA solid phase extraction column, performing gas chromatography-negative chemical ionization-mass spectrum (GC-NCI-MS) detection, establishing a correcting standard curve by adopting a blank matrix solution which does not contain pesticides, and quantifying by adopting an external standard method. With the adoption of the GC-NCI-MS determination method, the average recovery rate is 86.8%-96.9%, the average relative standard deviation (RSD) is 4.0-9.7%, the detection limit is 1.41 microg / kg; the GC-NCI-MS determination method has the advantages of simplicity and convenience in operation, rapidness, good impurity removal effect, high sensitivity, strong characteristic feather, good repeatability, and accuracy in qualitative and quantitative effect; the 0.01mg / kg residual limit for corresponding food safety detection by countries including America, Japan, European Union and Canada, namely, the technical requirement of uniform limit, is met, and therefore, powerful technical support is provided for guaranteeing food safety of Chinese people and healthy development of export trade.

The invention discloses a method for measuring indazole flusulfamide residue amount. The method comprises the following steps: homogenizing and extracting residual indazole flusulfamide in a sample by using acetonitrile or 1 percent of acetic acid-acetonitrile, dispersing and purifying the extracting solution through an ethidene diamine-N-propoxysilane (PSA) and octadecyl silane bonded phase (C18) matrix, performing liquid chromatography-tandem mass spectrometry (LC-MS / MS) detection, establishing a corrected standard curve by adopting dilution standards of a blank matrix solution, and quantifying through an external standard method. According to the method, the average recovery rate is 84.2-91.4 percent, the average relative standard deviation (RSD) is 3.7-6.6 percent, the detection limit is 1.53mu g / kg, and the method has the advantages of simplicity and convenience in operation, high rapidness, high accuracy, high sensitivity and high repeatability. The technical requirements on the safety detection of corresponding products in European Union, USA, Korea, Japan, Taiwan and other countries can be met, and powerful technical support is provided for guaranteeing the food safety of people in China and the export abroad trade health development.

The invention discloses a method for detecting acyl chloride in a medicine or synthesized intermediate thereof by a derivatization HPLC-DAD method. The method comprises the following steps: derivatizing acyl chloride with a nitrophenylhydrazine derivatized reagent at room temperature to generate a product has relatively absorbability in an ultraviolet visible region; separating and detecting the derivatized product of acyl chloride in the ultraviolet visible region by using the derivatized reacting liquid as a feeding sample based on the principle of reversed-phase high-performance liquid chromatography so as to qualitatively or quantitatively detecting acyl chloride. Based on the quick reaction characteristic of acyl chloride and hydrazino and the ultraviolet visible absorption characteristic of the product generated after acyl chloride and nitrophenylhydrazine perform a biochemical reaction, interference of a medicine or the synthesized intermediate matrix thereof on acyl chloride detection can be effectively avoided, so that a simple and universal method for detecting acyl chloride in a medicine or synthesized intermediate thereof by a derivatization HPLC-DAD method can be established. Methodological verification results indicate that the method has excellent specificity and sensitivity.

The invention discloses a method for detecting amine harmful substances in food. The detection method comprises the following steps: (1) adding a dispersed adsorbent into a sample, uniformly performing mixing, adding an acrylamide isotope internal standard and a heterocyclic amine compound isotope internal standard, carrying out ultrasonic extraction and centrifugal separation by adopting an acetonitrile aqueous solution, taking supernate, blowing nitrogen to 0.5-1mL, and fixing the volume by using an ammonium acetate solution containing acetic acid to obtain a purified solution; (2), adding ferroferric oxide nanoparticles into the purified liquid, carrying out vortex oscillation decolorization and centrifugation, and taking supernatant as to-be-detected liquid; and (3), detecting the amine harmful substances in the to-be-detected liquid by using an ultra-high performance liquid chromatography-tandem mass spectrometry method. The method has the advantages of excellent purification effect, high sensitivity and strong specificity, and is suitable for simultaneous determination of a plurality of amine harmful substances in food.

The invention provides a method for determining medicine or trinitride in the intermediate of the medicine through a derivatization HPLC (high performance liquid chromatography) method. The method comprises the following steps: performing derivatization reaction for 5-60 minutes on the trinitride firstly by utilizing a biphenyl acyl chloride derivatization reagent at experimental temperature, andenabling reaction liquid to serve as a sample to perform detection; taking derivation reaction liquid, which is generated above, as a sample, measuring a derivatization product with a wavelength between 220nm and 300nm by utilizing an HPLC-DAD (diode array detector) method so as to realize quantitative determination of the medicine or the trinitride in the synthesized intermediate of the medicine.The method can be used for avoiding matrix interference brought about by the medicine or the synthesized intermediate per se to establish a pre-column derivatization method which is high in sensitivity, high in specificity, simple and universal, then the HPLC method is used for measuring the residue of the medicine or the trinitride in the synthesized intermediate of the medicine, and the sensitivity and specificity of the method for determining the trinitride are improved.

The invention discloses a method for measuring fluoroether bacterial amide residues in fruit and vegetable by the GC-EI-MS (Gas Chromatography-Electron Bombardment Ion Source-Mass Spectrum). The method comprises the following steps: using acetonitrile or an acetonitrile solution containing 1% acetic acid to perform homogenization extraction on residual fluoroether bacterial amide in a sample, dispersing and purifying the extracting solution with the ethanediamine-N-propyl silane (PSA) and octadecyl silane bonded phase (C18) substrate, performing GC-EI-MS detection, and adopting a blank substrate solution without the pesticide to be measured to build a corrected standard curve, and using an external standard method to determine the quantity. According to the method, the average recovery rate is 93.5-99.0%, the average relative standard deviation (RSD) is 3.7-5.5%, and the detection limit is lower than 2.53 microgram / kg; the method has the advantages of being simple, convenient and quick to operate, high in sensitivity, good in repeatability, and accurate in qualitative and quantitative performance; the method can meet the technical requirement of uniform limit that the residual limit is 0.01 mg / kg, and provides a powerful technical support for food safety and export trade sound development in China.

The invention discloses a method for detecting chloramphenicol residual in a functional food through HPLC-MS-MS. The method comprises the following steps: weighing a sample, adding deuterated chloramphenicol as an internal standard solution, adding ethyl acetate, ammonium hydroxide and anhydrous sodium sulfate, homogeneously extracting, centrifuging, and transferring the obtained supernatant to a heart-shaped bottle; concentrating the supernatant in the heart-shaped bottle to dryness; dissolving with water, carrying out ultrasonic treatment, adding n-hexane, carrying out vortex mixing, allowing the obtained solution to stand for layering, discarding n-hexane which is the upper layer, adding n-hexane, carrying out vortex mixing, allowing the obtained solution to stand for layering, transferring the obtained water phase to a centrifuge tube, centrifuging, and allowing the centrifuged water phase to go through a filter membrane to obtain a final solution for the determination through HPLC-MS-MS; accurately weighing a chloramphenicol standard substance, carrying out ultrasonic dissolving with chromatographically pure methanol, adding the chromatographically pure methanol to a constant volume, and preparing chloramphenicol standard substance solutions having different concentrations; determining the chloramphenicol standard substance solutions through the HPLC-MS-MS to obtain a standard curve; and calculating according to obtained examination data through the standard curve to obtain the concentration of chloramphenicol in the sample to be measured. The method has the advantages of good accuracy, high precision and good linearity.

The invention discloses a GC-MS / MS (gas chromatography-mass spectrometry / mass spectrometry) determination method of residual amount of fluoride ether bacterium amide. The method is mainly used for determining the residual amount of fluoride ether bacterium amide in cereal grains, animal-derived foods and other complex matrix food agricultural products. The method comprises the following steps: homogenizing and extracting residual fluoride ether bacterium amide in a sample with acetonitrile or an acetonitrile solution containing 1% of acetic acid, performing purification and concentration by a C18 / PSA solid-phase extraction column, performing GC-MS / MS detection, establishing a standard curve for correction by adopting a blank matrix solution without a pesticide to be detected, and quantifying by an external standard method. According to the method, the average recovery rate is 87.1%-93.8%, the average relative standard deviation (RSD) is 4.1%-5.2%, the detection limit is lower than 0.51mu g / kg, and the method has the advantages of simplicity and convenience in operation, high speed, good impurity removal effect, high sensitivity, good repeatability and accurate qualitative and quantitative properties. According to the method, the technical requirement of 'being standard without exceptions' of the residual limit of 0.01mg / kg can be met, and a powerful technical support is provided for ensuring food safety of people in China and health development of export trades.

The invention discloses a method for measuring the residual amount of chlorantraniliprole in vegetables and fruits. The method disclosed by the invention comprises the following steps: homogenizing and extracting chlorantraniliprole residual in a sample by using acetonitrile or an acetonitrile solution containing 1% of acetic acid, dispersing and purifying an extraction solution through ethanediamine-N-propoxysilane (PSA) and an octadecylsilan bonded phase (C18), detecting through gas chromatography-electron impact ion source-mass spectrum (GC-EI-MS), establishing a corrected standard curve by using a vehicle solution free from a pesticide to be measured, and quantifying by using an external standard method. According to the invention, the average recovery rate is 89.6%-103.5%; the average relative standard deviation (RSD) is 4.4%-7.7%; the detection limit is less than 0.62 microgram / kg; and the method disclosed by the invention has the advantages of being simple, convenient and rapid to operate, high in sensitivity, good in repeatability and accurate in qualitative and quantitative performance, and can satisfy the technological requirements on safety detection of corresponding products in the countries, such as America, Japan, European union and Canada, and provide strong technical support for sound development of food safety and foreign export trade in China.

The invention discloses a determination method for the residual amount of metrafenone. The determination method comprises the following steps: homogenizing by using acetonitrile or 1% acetonitrile acetate to extract residual metrafenone in a sample; dispersing and purifying an extracting solution by ethylenediamine-N-propoxysilane (PSA) and an octadecyl silane bonded phase (C18) base material; carrying out liquid chromatogram-mass spectrum / mass spectrum (LC-MS / MS) detection; establishing a corrected standard curve by adopting a blank base material solution diluting standard; and quantifying by an external standard method. According to the method, the average recycling rate is 80.2%-94.9%; the average relative standard deviation (RSD) is 4.0%-6.8%; the detection limit is lower than 0.10 microgram / kilogram; the determination method has the advantages of simplicity and convenience in operation, rapidness, high sensitivity, good repeatability and accuracy in qualifying and quantifying. The technical requirements of corresponding product safety detection by countries including European Union, America, Korea, Japan and the like can be met and the powerful technical supports are provided for guaranteeing the food safety of people in China and the healthy development of export trades.

The invention relates to a measuring method of cloransulam-methyl residues in soybeans and soil, comprising the following concrete steps of: weighing 10-20g of samples and then putting in a conical flask with a plug; adding 20-60mL of pure water and standing for 10-30 min; then adding 50-70mL of acetonitrile; extracting for 30-60 min under vibration; filtering and transferring to a separating funnel; adding 20-30mL of 0.01mol / L hydrochloric acid and a saturated sodium chloride aqueous solution; vibrating for 3-10 min and standing for demixing; extracting again by using 50-100mL of acetonitrile, merging and concentrating to 10-30mL; purifying: sprinkling a solid phase extraction C18 column with the acetonitrile in advance, and purifying the extraction phase by adopting a column chromatography; collecting leaching liquid; concentrating for dryness; making at constant volume by using methanol and water the volume ratio of which is 1:1 and filtering through a filter membrane; and carrying out detection by adopting a liquid chromatogram method. The measuring method has the characteristics of simple and quick operation, high recovery rate, high sensitivity and small impurity interference and provides the reliable guarantee for rapidly and accurately measuring the cloransulam-methyl residues in the soybeans and the soil and establishing a simple and convenient and effective analysis method.

The invention discloses a GC-NCI-MS (gas chromatography-negative chemical ionization-mass spectrometry) testing method of residual quantity of cyantraniliprole. The method is mainly used for testing the content of cyantraniliprole remained in complex matrix food agricultural products such as cereal grains and animal-origin food. The method comprises the following steps: homogenously extracting cyantraniliprole remained in samples by using acetonitrile or acetonitrile solutions containing 1 percent of acetic acid; purifying and condensing by using a C18 / PSA solid-phase extraction column; detecting by GC-NCI-MS; building a corrected standard curve by using vehicle solutions which do not contain pesticides to be detected; and quantifying by using an external standard method. The method has the average recycling rate of 93.4-97.7 percent, the average relative standard deviation (RSD) of 4.0-7.3 percent and the detection limit of lower than 2.89 microgram / kg, has the advantages of convenience and quickness in operation, good impurity removal effect, high sensitivity, high property, high repeatability and accurate quantitativeness and qualitativeness, and can meet the technical requirement of uniform limit, namely 0.01 mg / kg maximum residue limit of corresponding food security detection, in America, Canada, European Union, Japan and the like, so that powerful technical support is provided for guaranteeing food security of people and healthy development of export trade in China.

The invention discloses a detecting method for the residual quantity of flubendiamide in fruits and vegetables. The detecting method comprises the steps of homogenizing by using acetonitrile or an acetonitrile liquid containing 1% acetic acid to extract residual flubendiamide in a sample; dispersing by using a primary secondary amine (PSA) and octadecylsilane bonded-phase (C18) matrix to purify an extracting liquid; then, carrying out gas chromatography-negative chemical ionization-mass spectrum (GC-NCI-MS) detection; establishing a corrected standard curve by using a blank matrix liquid without a pesticide to be detected; and quantifying by using an external standard method. By using the detecting method, the average recovery rate is 93.2-103.1%, the average relative standard deviation (RSD) is 4.6-7.4%, and the detection limit is lower than 1.15mu g / kg; and the detecting method is simple and convenient to operate, rapid, high in sensitivity, good in repeatability and accurate in qualitation and quantitation. According to the detecting method, the technical requirements of America, Japan, European union and other countries on security detection of corresponding products can be met, and the powerful technical support can be provided for ensuring Chinese food safety and the health development of foreign export trade.

The invention discloses a GC-NCI-MS (Gas Chromatography-Negative Chemical Ionization-Mass Spectrum) detecting method for the residual quantity of cyantraniliprole in fruits and vegetables. The GC-NCI-MS detecting method comprises the steps of homogenizing by using acetonitrile or an acetonitrile liquid containing 1% acetic acid to extract residual cyantraniliprole in a sample; dispersing by using a primary secondary amine (PSA) and octadecylsilane bonded-phase (C18) matrix to purify an extracting liquid; then, carrying out GC-NCI-MS detection; establishing a corrected standard curve by using a blank matrix liquid without a pesticide to be detected; and quantifying by using an external standard method. By using the GC-NCI-MS detecting method, the average recovery rate is 89.2-96.7%, the average relative standard deviation (RSD) is 3.5-8.8%, and the detection limit is lower than 0.53mu g / kg; and the GC-NCI-MS detecting method is simple and convenient to operate, rapid, high in sensitivity, good in repeatability and accurate in qualitation and quantitation. According to the GC-NCI-MS detecting method, the technical requirements of America, Canada, European union, Japan and other countries on security detection of corresponding products can be met, and the powerful technical support can be provided for ensuring Chinese food safety and the health development of foreign export trade.

The invention discloses a GC-EI-MS (Gas Chromatography-Electron Ionization-Mass Spectrum) detecting method for the residual quantity of cyenopyrafen in fruits and vegetables. The GC-EI-MS detecting method comprises the steps of homogenizing by using acetonitrile or an acetonitrile liquid containing 1% acetic acid to extract residual cyenopyrafen in a sample; dispersing by using a primary secondary amine (PSA) and octadecylsilane bonded-phase (C18) matrix to purify an extracting liquid; then, carrying out GC-EI-MS detection; establishing a corrected standard curve by using a blank matrix liquid without a pesticide to be detected; and quantifying by using an external standard method. By using the GC-EI-MS detecting method, the average recovery rate is 87.2-92.6%, the average relative standard deviation (RSD) is 4.0-6.5%, and the detection limit is lower than 1.33mu g / kg; and the GC-EI-MS detecting method is simple and convenient to operate, rapid, high in sensitivity, good in repeatability and accurate in qualitation and quantitation. According to the GC-EI-MS detecting method, the technical requirements of Korea, Japan, European union and other countries on security detection of corresponding products can be met, and the powerful technical support can be provided for ensuring Chinese food safety and the health development of foreign export trade.

The invention discloses a liquid chromatography-mass spectrometry / mass spectrometry (LC-MS / MS) measuring method for the Si lv chong xian'an residue quantity. The LC-MS / MS measuring method is mainly used for measuring the quantity of residual Si lv chong xian'an in complex matrix food agricultural products such as cereal grain food and animal derived food. The residual Si lv chong xian'an in a sample is homogeneously extracted through acetonitrile or an acetonitrile solution containing 1% acetic acid, LC-MS / MS testing is conducted after purification is conducted through a C18 / PSA solid-phase extraction column, a corrected standard curve is established through a blank matrix solution without containing pesticide to be tested, and quantification is conducted through an external standard method. According to the LC-MS / MS measuring method, the average recovery rate ranges from 84.9% to 93.6%, the average relative standard deviation (RSD) ranges from 4.1% to 6.5%, the detection limit is smaller than 0.69 microgram per kilogram, and the LC-MS / MS measuring method has the advantages that operation is easy, convenient and rapid, the impurity removal effect is good, sensitivity is high, repeatability is good, and qualitative and quantitative operation is accurate; the technical requirement of 0.01mg / kg residual limit for the uniform limit can be met, and powerful technical support is provided for food safety of people in China and healthy development of foreign export trade.

The invention discloses a quick GC (Gas Chromatograph)-MS (Mass Spectrometry) / MS determining method of the residual quantity of fluxapyroxad. The GC-MS / MS determining method is mainly used for determining the content of residual fluxapyroxad in animal derived food which is high in fat content. The GC-MS / MS determining method comprises the following steps: homogeneously extracting the residual fluxapyroxad in a sample by using acetonitrile; carrying out GC-MS / MS detection after dispersing and purifying matrix of an extracting solution by using an EMR (Enhanced Matrix Removal) and extracting and concentrating by using a reverse extraction tube; building a corrected standard work curve by adopting a blank-matrix solution which does not contain to-be-detected pesticide; quantifying through an external standard method. According to the GC-MS / MS determining method of the residual quantity of the fluxapyroxad, disclosed by the invention, the average recovery rate is 93.6 to 98.7 percent, the average RSD (Relative Standard Deviation) is 5.0 to 7.4 percent, and the detection limit is lower than 0.044 mug / kg; the GC-MS / MS determining method has the advantages that the operation is convenient and fast, the impurity removing effect is good, the sensitivity is high, the characteristic performance is strong, the repeatability is good, and qualitativeness and quantitativeness are precise; the technical requirements on safety detection of corresponding products of countries of America, EU (European Union), Japan and the like can be met, and a powerful technical support is provided for ensuring the safety of food for people in China and the healthy development of export trade.

The invention discloses a GC-NCI-MS (gas chromatography-negative chemical ionization-mass spectrometry) determination method of residual amount of fluoride ether bacterium amide. The method is mainly used for determining the residual amount of fluoride ether bacterium amide in cereal grains, animal-derived foods and other complex matrix food agricultural products. The method comprises the following steps: homogenizing and extracting residual fluoride ether bacterium amide in a sample with acetonitrile or an acetonitrile solution containing 1% of acetic acid, performing purification and concentration by a C18 / PSA solid-phase extraction column, performing GC-NCI-MS detection, establishing a standard curve for correction by adopting a blank matrix solution without a pesticide to be detected, and quantifying by an external standard method. According to the method, the average recovery rate is 85.0%-91.1%, the average relative standard deviation (RSD) is 4.1%-6.6%, the detection limit is lower than 0.35mu g / kg, and the method has the advantages of simplicity and convenience in operation, high speed, good impurity removal effect, high sensitivity, strong characteristic feature, good repeatability and accurate qualitative and quantitative properties. According to the method, the technical requirement of 'being standard without exceptions' of the residual limit of 0.01mg / kg can be met, and a powerful technical support is provided for ensuring food safety of people in China and health development of export trades.

The invention discloses a method for determining residual amount of metrafenone. The method is mainly used for determining the residual amount of metrafenone in cereal grains, animal-derived foods and other complex matrix food agricultural products. The method comprises the following steps: homogenizing and extracting residual metrafenone in a sample with acetonitrile or an acetonitrile solution containing 1% of acetic acid, performing purification and concentration by a C18 / PSA solid-phase extraction column, performing gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS) detection, establishing a standard curve for correction by adopting a blank matrix solution without a pesticide to be detected, and quantifying by an external standard method. According to the method, the average recovery rate is 83.9%-90.1%, the average relative standard deviation (RSD) is 4.0%-5.8%, the detection limit is lower than 0.67mu g / kg, and the method has the advantages of simplicity and convenience in operation, high speed, good impurity removal effect, high sensitivity, strong characteristic feature, good repeatability and accurate qualitative and quantitative properties. According to the method, the technical requirements on safety detection of corresponding products in European Union, United States, South Korea, Japan and other countries can be met, and a powerful technical support is provided for ensuring food safety of people in China and health development of export trades.

The invention discloses a GC-EI-MS measuring method of the residual quantity of spirotetramat in fruit and vegetable. The method comprises performing homogeneous extraction on spirotetramat residue in a sample through acetonitrile or an acetonitrile solution containing 1% of acetic acid; performing dispersed purification on extracted solution through ethylenediamine-N-propyl silicane (PSA) and octadecyl silane bonded phase (C18) matrix; then performing GC-EI-MS detection, establishing a calibration standard curve through blank matrix solution not containing pesticide to be measured, and performing quantitation through the external standard method. The GC-EI-MS measuring method of the residual quantity of spirotetramat in fruit and vegetable achieves an average recovery rate of 86.4-93.2%, an average relative standard deviation (RSD) of 4.1-7.4% and a detection limit lower than 2.87 mu g / kg, has the advantages of being convenient and rapid to operate, high in sensitivity and repeatability and accurate in quantitation and quantification, can meet the technical requirements of the corresponding product safety inspection of nations such as the U.S., Japan, the European Union and Canada, and provides powerful technical support for food safety of people and healthy development of export trade in China.

The invention discloses a GC-EI-MS method for rapidly determining the residual aminobenzene pyrazolone amount.The method is mainly used for determining the residual aminobenzene pyrazolone amount in animal derived foods with high fat content.Acetonitrile is adopted to homogeneously extract the residual aminobenzene pyrazolone in a sample, the extracting solution is subjected to matrix dispersion and purification of an enhanced matrix removal (EMR) product and extraction by a reverse extraction tube and concentration are conducted, then gas chromatography-electron impact ionization-mass spectrometry (GC-EI-MS) detection is performed, a blank matrix solution containing no pesticide to be detected is adopted to establish a standard working curve for correction, and quantification is performed by adopting an external standard method.The average recovery rate of the method is 92.0%-93.4%, the average relative standard deviation (RSD) of the method is 4.6%-7.0%, the detection limit of the method reaches 2.19 micrograms / kilogram or below, and the method has the advantages of being simple and convenient to operate, rapid, good in impurity removal effect, high in sensitivity, good in characteristic performance and repeatability and accurate in qualititation and quantification, can meet the technical requirements for corresponding product safety detection of the United States, European Union, Japan and other countries and provides a powerful technical support for ensuring the people's food safety and healthy development of the abroad export trade of our country.

The invention discloses a method for determining phenylhydrazine and phenylhydrazine derivatives in medicine or synthetic intermediate by a derivatization HPLC-DAD method. The method is characterizedin that a benzaldehyde type derivatization reagent, and the phenylhydrazine and the phenylhydrazine derivative react to generate a product has strong absorption performance in a near visible light-visible light region; derivatization reaction liquid is used as a sample; the reaction product of the phenylhydrazine and the phenylhydrazine derivative is determined in the near visible light-visible light region on the basis of reversed-phase high performance liquid chromatography principle, so that the qualitative or quantitative detection of the phenylhydrazine and the phenylhydrazine derivativeis realized; the absorption wavelength of the derivatization product has obvious redshift, so that the substrate interference of the medicine or synthetic intermediate can be effectively avoided. Inaddition, the methodology validation result shows that the method has high specificity and sensitivity.

The invention discloses a method for measuring aromatic amine in crayons, which comprises the following steps of: cutting crayons into small pieces, performing ultrasonic pretreatment on samples by using normal hexane, cyclohexane or heptane, and removing the normal hexane, the cyclohexane or the heptane to obtain pretreatment samples; performing ultrasonic extraction on the pretreatment samples by using methanol, ethanol, isopropanol or acetonitrile to obtain extracting solution; removing organic solvent in the extracting solution, and adding sodium hyposulfite solution to perform a reduction reaction at the temperature of between 60 and 80 DEG C; after the reaction is finished, regulating the pH value of reaction solution to be between 7 and 9, adsorbing by a siliceous earth column, andeluting by using methyl tertiary butyl ether or diethyl ether to obtain eluent; and adding 0.5 to 1 mol / L hydrochloric acid solution into the eluent, removing an organic layer on an upper layer, regulating the pH value of a residual aqueous phase to be between 7 and 9, adding the methyl tertiary butyl ether or the diethyl ether, and after an organic phase and the aqueous phase are layered completely, extracting the organic phase to measure the aromatic amine in a gas chromatograph-mass spectrometer. The method disclosed by the invention fills the blank of the technology, and the problem of matrix interference caused by other ingredients in the crayons is solved effectively.

The invention discloses a GC-NCI-MS (gas chromatography-negative chemical ionization-mass spectrometry) determination method of residual amount of metrafenone in fruits and vegetables. The method comprises the following steps: homogenizing and extracting residual metrafenone in a sample with acetonitrile or an acetonitrile solution containing 1% of acetic acid, performing dispersion and purification on an extraction solution with a matrix of ethylenediamine-N-propylsilane (PSA) and octadecylsilane bonded phase (C18), then performing GC-NCI-MS detection, establishing a standard curve for correction by adopting a blank matrix solution without a pesticide to be detected, and quantifying by an external standard method. According to the method, the average recovery rate is 89.9%-94.9%, the average relative standard deviation (RSD) is 4.1%-6.2%, the detection limit is lower than 1.02mu g / kg, and the method has the advantages of simplicity and convenience in operation, high speed, high sensitivity, good repeatability and accurate qualitative and quantitative properties. According to the method, the technical requirements on safety detection of corresponding products in European Union, United States, South Korea, Japan and other countries can be met, and a powerful technical support is provided for ensuring food safety of people in China and health development of export trades.

The invention discloses a method for determining a SYP-9080 residue in fruits and vegetables by employing gas chromatography-electron impact ion source-mass spectrum (GC-EI-MS). The method comprises the following steps: extracting residual SYP-9080 from a sample with acetonitrile or an acetonitrile solution containing 1% acetic acid in a manner of homogenization; dispersing and purifying extract liquid with ethidene diamine-N-propyl silane (PSA) and octadecyl silane bonded-phase (C18) matrix, and then carrying out GC-EI-MS detection; and building a corrected standard curve with a blank matrix solution free of a to-be-detected pesticide, and quantifying by an external standard method. According to the method, the average recovery rate is 86.3%-93.2%; the relative average standard deviation (RSD) is 4.2%-7.6%; the detection limit is lower than 7.85 microg / kg; and the method has the advantages of simplicity, convenience and fastness in operation, high sensitivity, good repeatability and accurate qualify and quantify, and can meet the technical requirements of uniform standard of 0.01mg / kg of residue limit; and a powerful technical support is provided for guarantee of the food safety for people in China and health development of foreign export trade.

The invention provides a method for determining the residual amount of thiediazole copper in dendrobium officinale. The method comprises adding a sodium sulfide solution into a dendrobium officinale sample so that the thiediazole copper is derived and transformed into a metabolite thiadiazole, carrying out extraction with acetonitrile, adding an acid into the extract to adjust pH, adding ethyl acetate into the extract, carrying out liquid-liquid distribution, carrying out concentration drying through an organic phase through a rotary evaporator, removing interfering substances in the extract through a solid phase extraction method and carrying out detection through an ultra-high performance liquid chromatography-mass spectrometer / mass spectrometer. The method can effectively prevent samplematrix interference and has good results. The method has high accuracy, precision and sensitivity, has a high recovery rate and small interference of impurities and can effectively determine the content of thiediazole copper in the dendrobium candidum.