9results about How to "Reduce matrix effect" patented technology

The invention relates to the field of detection, in particular to a method for determining the residual quantity of methoprene and methoprene in citrus through pre-column derivatization liquid chromatography-tandem mass spectrometry, and the method comprises the following steps: S1, preparation of a standard sample and a to-be-detected sample: S11, preparation of the standard sample, and S12, preparation of the to-be-detected sample; s2, preparation and derivation of a standard sample solution and a to-be-detected sample solution: S21, extraction, S22, purification and S23, derivation; s3, measuring; s4, establishing a linear equation; and S5, analyzing the sample to be detected. The technical problems that in the prior art, the ionization efficiency of methoprene and methoprene in the electrospray process is low due to the non-polar property of methoprene and methoprene, and electrospray ionization tandem mass spectrometry detection of methoprene and methoprene lacks the sensitivity required by trace analysis can be solved. The detection sensitivity of methoprene and methoprene in citrus fruits can be obviously improved.

The invention belongs to the field of analytical chemistry, and provides a method for simultaneously determining 10 tryptophan metabolites through liquid chromatography-mass spectrometry, differentiated pretreatment schemes are designed aiming at different biological matrixes such as excrement, serum, colon tissue and NCM460 inflammatory cells through a liquid chromatography-tandem mass spectrometry technology, matrix interference is effectively eliminated, and the method for simultaneously determining 10 tryptophan metabolites through liquid chromatography-mass spectrometry is provided. A quantitative analysis method with high sensitivity and high selectivity is established; the method is successfully applied to an ulcerative colitis (UC) rat model and a lipopolysaccharide (LPS)-induced NCM460 inflammation model, and a technical means is provided for revealing a metabolic regulation mechanism of medicine intervention on UC; the method solves the technical problem that various metabolites in a tryptophan metabolic pathway are difficult to detect in the prior art, is suitable for metabolic mechanism research, drug intervention effect evaluation and large-scale detection of clinical samples of inflammatory bowel diseases such as UC, and provides a technical basis for systematic research of a tryptophan metabolic network.

The invention belongs to the technical field of magnetic solid-phase extraction and analysis. The invention provides a method for quantitatively detecting bisphenol pollutants in traditional Chinese medicines for soil and roots based on a magnetic MOF (at) COF porous composite material combined with LC-MSMS. The method comprises the steps of preparation of the magnetic MOF (at) COF porous composite material, sample pretreatment and LC-MSMS detection and quantitative analysis. The magnetic MOF (COF) porous composite material disclosed by the invention has rich hierarchical pore structures and high specific surface area, not only retains regular pore channels and active sites of a metal organic framework (MOF), but also is connected with a covalent organic framework (COF), so that the stability of the material is greatly improved. Meanwhile, the material is mild in preparation condition, low in cost and excellent in adsorption performance. Compared with the existing method, the detection method provided by the invention has the advantages of more thorough extraction, lower detection limit, higher recovery rate, simpler operation and lower cost, and is suitable for two matrixes of soil and root system traditional Chinese medicines.

The invention provides a method for detecting Hainanmycin residues in poultry meat, eggs and egg products and a pretreatment method, and belongs to the technical field of food detection. The pretreatment method comprises the following steps: (1) adding a sample to be detected into an extraction solvent for extraction; (2) adding anhydrous magnesium sulfate and sodium chloride; (3) centrifuging to obtain supernate; (4) loading the supernate onto a solid-phase extraction small column, purifying and collecting to obtain first effluent; (5) loading an extraction solvent onto the small solid-phase extraction column, collecting to obtain a second effluent, and combining all the effluent; and (6) concentrating, redissolving and filtering all the effluent to obtain a sample solution to be detected. The invention further discloses a method for detecting Hainanmycin residues through liquid chromatography-mass spectrometry after a sample is pretreated, the method has the advantages of being rapid, efficient, low in detection limit and good in reproducibility, the blank of a method for detecting Hainanmycin in animal-derived food is filled, and the method is suitable for trace detection of Hainanmycin.

The present application belongs to the field of chromatographic packing, discloses an adsorbing packing for purification column and its preparation method and use. A polyethylene oxide and clay composite material, the composite material comprises the following raw materials by weight: inorganic salt modified clay 4000-8000 parts, quaternary ammonium salt compound 50-100 parts, polyethylene oxide 1 part. The present application also provides an adsorbing packing for purification column, which can effectively and selectively adsorb protein, lipid and other impurities in the pretreatment extraction liquid for mycotoxin detection, has a small matrix effect, and has a high absolute recovery rate for several typical mycotoxin target objects.

This invention relates to a method for detecting metal elements in electronic-grade boron-aluminum doped source samples. The method includes microwave digestion of the sample and inductively coupled plasma atomic emission spectrometry (ICP-AES) to detect the metal element content. By optimizing sample pretreatment and instrument detection conditions, this invention achieves high-precision determination of multiple metal elements in electronic-grade boron-aluminum doped sources. The accuracy, precision, and sensitivity of the detection results meet the requirements for ultra-trace detection of semiconductor-grade and photovoltaic-grade boron-aluminum doped sources.

The invention relates to the technical field of biological products, in particular to a preparation method of a myocardial marker composite quality control substance, which comprises the following steps: firstly, treating serum to prepare a quality control substance matrix liquid, further testing the concentration of myocardial markers in the quality control substance matrix liquid, screening out low-concentration-value human serum and high-concentration-value human serum, and determining the concentration of the myocardial markers in the quality control substance matrix liquid. Selecting a positive myocardial marker pure product to prepare a myocardial marker substance control solution without pure product addition and a myocardial marker substance control solution with pure product addition, synthesizing the corresponding myocardial marker substance control solution, adding disodium hydrogen phosphate dodecahydrate and sodium dihydrogen phosphate dihydrate, adjusting the pH value, sequentially adding corresponding elements, and uniformly mixing to obtain the myocardial marker substance. According to the myocardial marker substance control substance provided by the invention, the matrix effect in different detection methodologies can be effectively reduced; the stability of a detection result can be remarkably improved, and the preparation method has the characteristics of good stability and uniformity, high redissolution speed, low viscosity, small matrix effect and simplicity and convenience in preparation.

This invention discloses a method for detecting bromofenac in ginger, belonging to the field of pesticide residue detection technology. The method includes: homogenizing and extracting ginger samples using an acetonitrile solution containing a hydrophobic deep eutectic solvent; adding a salting-out agent to obtain a supernatant through separation; purifying the supernatant using a boric acid-functionalized magnetic carbon nanotube metal-organic framework composite material as an adsorbent via a temperature-switching adsorption process, first removing phenolic interference through thermal adsorption, then removing lipids through freeze precipitation; and finally detecting the supernatant using liquid chromatography-tandem mass spectrometry. This invention effectively solves the problem of severe matrix interference from phenols and lipids in ginger, and features high recovery rate, low matrix effect, high sensitivity, and simple operation.

The application discloses an artificial urine buffer matrix and a preparation method and application thereof. The artificial urine buffer matrix comprises urea, uric acid, alpha-hydroxy acid, amino acid, ions and sugar. The artificial urine buffer matrix can eliminate background interference, guarantee the immune reaction detection of small molecules, proteins and other biomarkers in urine, and has small matrix effect.