30results about How to "Meet the needs of trace detection" patented technology

The invention discloses a method for rapid detection of dimehypo and simazine in a tea on site. The method comprises (1) preparing a silver-ammonia solution, (2) constructing a PAD-based analysis device, (3) preparing a silver nanoparticle (Ag NPs) paper chip by a silver mirror reaction, (4) wiping the surfaces of dimehypo and simazine samples through the paper chip, and (5) detecting the paper chip through a portable Raman spectrometer to obtain SERS spectrums of the samples and comparing the spectrums of dimehypo and simazine solids to realize qualitative and quantitative detection. Comparedwith the prior art, the method has the characteristics of rapid analysis, high sensitivity, small sample consumption, wide application range, simple operation and convenient carrying, can realize analysis and detection of insecticidal dimehypo and simazine in a tea and has detection limits of 1.2*10<-10>moL / L and 1.0*10<-9>moL / L respective to dimehypo and simazine.

The invention discloses a field rapid detection method for trichlorfon and simazine in seawater. It includes the following steps: (1) synthesizing gold nanorods by seed crystal method; (2) adding L-cysteine ​​to the gold nanorod solution to obtain L-cysteine-modified gold nanorod materials; (3) Synthesis of gold nanospheres by hydrothermal method; (4) adding p-mercaptoaniline to gold nanospheres to obtain gold nanosphere composites modified by p-mercaptoaniline; (5) gold nanorod materials modified by L-cysteine Mix with the gold nanosphere composite material modified by p-mercaptoaniline, and obtain the gold nanorod and gold nanosphere composite material through the action of peptide bond, as the SERS active substrate; (6) use the Raman spectrometer to detect trichlorfon and simazine, thereby Qualitative and quantitative analysis and detection of trichlorfon and simazine in seawater. The invention has the characteristics of rapid analysis, high sensitivity, less sample consumption, wide application range, simple operation, convenient portability and the like.

The invention relates to a preparation method for a stable isotope reagent sodium borodeuteride. The method comprises the following steps: (1) pre-treating a boron-containing substance and quartz sand for complete dehydration, loading the boron-containing substance and the quartz sand in a sealed reaction kettle, adding a pretreated active metal from which a surface oxide layer is removed, connecting a deuterium bag to the sealed reaction kettle, performing heating and stirring, and sucking deuterium for reaction until the volume of the deuterium bag is kept unchanged; (2) after reaction is ended, performing cooling to obtain a sodium borodeuteride product. Compared with the prior art, the preparation method has the advantages that a preparation process route is simple, a preparation condition is mild, less waste gas, wastewater and industrial residues are generated by reaction, and moreover, the prepared sodium borodeuteride has purity capable of reaching 99 percent or above, abundance of 99.9atom% or above and the like.

The present invention relates to a stable isotope-marked basic tender yellow O and a synthesis method thereof. Said stable isotope marked basic tender yellow O is basic tender yellow O marked with D or 15N or 13C. During preparation, the stable isotope D or 15N or 13C-labeled methanol and aniline are used as raw materials to synthesize stable isotope D or 15N or 13C-labeled N,N-dimethylaniline precursors, which are then condensed, sulfurized and ammoniated to make stable isotope D or 15N or 13C-labeled bases Sexually bright yellow O. Compared with the prior art, the method of the invention has the advantages of simple process route, easy synthesis, easy separation and purification of products, chemical purity of products of more than 99.0%, isotopic abundance of more than 98.0% atom, which can fully meet the requirements of trace detection in the field of food safety. The economy and use value are good, and it has a good promotion prospect.

The invention discloses a method for detecting dibutyl phthalate through a fluorescence ratio method based on dual-emission carbon quantum dot marked nucleic acid aptamer. Sensitive detection of dibutyl phthalate is realized by taking dual-emission carbon quantum dots as a marker and combining with an aminated nucleic acid aptamer specifically recognizing dibutyl phthalate; the method is low in detection limit, high in specificity, stable in fluorescent performance and suitable for ultrasensitive quick detection of dibutyl phthalate in food.

The invention discloses a method for detecting kanamycin sulfate by double-signal-enhanced surface-enhanced Raman spectroscopy, which belongs to the technical field of food safety detection. The present invention uses gold nanorods with controllable surface plasmon resonance peaks as the Raman substrate, and combines the cascaded redox reaction catalyzed by metal-doped carbon quantum dots and the switch structure controlled by nucleic acid aptamers to establish a dual enhanced Raman signal The advanced kanamycin sulfate detection system further improves the sensitivity of detecting kanamycin sulfate. The invention has low detection limit, good specificity, is simple and fast, and is suitable for ultrasensitive detection of kanamycin sulfate in food.

The invention relates to stable isotopic labeled 2-isopropylthioxanthone and a synthetic method thereof. The stable isotopic labeled 2-isopropylthioxanthone is 2-isopropylthioxanthone labeled by D or 13C. The synthetic method comprises the following steps of using benzene and acetone which are labeled by stable isotopic D or 13C as raw materials; reacting the benzene and the acetone with magnesium to obtain Grignard reagent after benzene bromination; performing reduction and hydroxide radical bromination on the acetone to obtain 2-bromic propane; performing Grignard reaction to obtain isopropyl benzene; reacting the isopropyl benzene with dithio-salicylic acid; and synthesizing to obtain the 2-isopropylthioxanthone labeled by the stable isotopic D or 13C. Compared with the prior art, the stable isotopic labeled 2-isopropylthioxanthone has the advantages that a process route is simple, the 2-isopropylthioxanthone is easy to synthesize, products are easy to separate and purify, the chemical purity of the products is above 99.0%, isotope abundance is above 98.0% atom, requirements of trace detection in the field of food safety can be met fully, and economical efficiency and using value are excellent.

The invention relates to a synthesis method of stable isotope-labeled prohibited pigments. The method uses stable isotope D or 13C-labeled bromobenzene to synthesize stable isotope D- or 13C-labeled intermediate sodium p-aminobenzenesulfonate through ammoniation and sulfonation , or use bromobenzene as a raw material, and ammonate and sulfonate the stable isotope 15N-labeled intermediate sodium p-aminobenzenesulfonate through ammoniation and sulfonation with a stable isotope 15N-labeled ammoniation reagent, and then undergo diazotization and coupling to obtain stable synthesis Prohibited pigments labeled with isotope D or 15N or 13C. Compared with the prior art, the process route of the present invention is simple, easy to synthesize, easy to separate and purify the product, the chemical purity of the product is above 99.0%, and the isotope abundance is above 98.0% atom, which can fully meet the needs of trace detection in the field of food safety. It has good economy and use value.

The invention provides an electron ionization source, including an electron source, a repulsion electrode and an ion lens, and further including a first cylindrical component, an annular component and a second cylindrical component, wherein the electron source is arranged at the side part of the first cylindrical component, the repulsion electrode is arranged in the first cylindrical component with two open ends, the annular component is arranged on one side of the first cylindrical component, one side, far away from the first cylindrical component, of the annular component is provided with an outlet, and the inner diameter of the hollow inner part of the annular component is gradually reduced along the emitting direction of ions, the second cylindrical component is arranged in the outlet, and the iron lens is arranged on one side of the second cylindrical component along the emitting direction of the ions. The electron ionization source has the advantage of being high in ion emitting efficiency.

The invention relates to a synthesis method of a stable isotope-labeled beta receptor agonist type compound. The synthesis method comprises the following steps: (1) by taking stable isotope-labeled methanol as a raw material, reacting with acetone or stable isotope-labeled acetone, and ammonifying to obtain stable isotope-labeled tert-butylamine; and (2) by taking a bromoketone type compound as a precursor of the beta receptor agonist type compound, reacting with stable isotope-labeled tert-butylamine to prepare the stable isotope-labeled beta receptor agonist type compound. Compared with the prior art, the method for preparing the stable isotope-labeled beta receptor agonist, provided by the invention, is simple, safe and reliable, the chemical purity of the product after separation and purification is above 99.0%, the isotopic abundance is above 98.0% atom, and the product can fully meet the requirements of residual detection in the field of food safety.

The invention discloses a method for rapidly detecting sulfur dioxide in wine on-site. The method comprises the following steps: (1) after placing a reduced graphene solution, 4-mercaptopyridine and agold nano-rod in a PBS (Phosphate Buffer solution) at room temperature, centrifuging and washing to obtain AuNRs / rGO-MPy; (2) filtering the AuNRs / rGO-MPy through an Anodisc filtering membrane to obtain an AuNRs / rGO-MPy filtering membrane; combining a Karl-Fisher reagent to construct a headspace sampling / paper-based analysis device; detecting sulfur dioxide by utilizing an ultraviolet spectrophotometer and a portable Raman spectrometer. The method disclosed by the invention has the advantages of simplicity and portability in operation, relatively rapid response, high selectivity and good sensitivity; a dual-sensing detection mode can realize optimal sensing performance of sulfur dioxide in a complicated matrix sample and the risks of false positive and false negative are reduced. Detectionlimits are as follows: a colorimetric method: 5.0mu M; an ultraviolet-visible spectrophotometry: 1.45mu M; SERS (Surface Enhanced Raman Scattering): 0.086mu M.

The invention discloses a method for on-site rapid detection of amoxicillin antibiotics in water bodies. It comprises the following steps: (1) synthesize copper metal-organic framework Cu-MOFs on the surface of screen-printed electrodes by electrochemical method; (2) synthesize Ag / Cu-BTC composite nanometer by in-situ growth method on the surface of Cu-MOFs material; (3) the amoxicillin antibiotic in the water body to be tested is enriched in Ag / Cu-BTC; (4) utilizes the portable Raman spectrometer to detect the enriched amoxicillin, thereby the amoxicillin in the water body to be tested is qualitatively and Quantitative analysis detection. The present invention not only has the characteristics of rapid analysis, high sensitivity, less sample consumption, wide application range, simple operation, and convenient portability; Analytical detection of amoxicillin antibiotics with a limit of detection of 1.8×10 ‑10 M.

The invention provides a miniature light derivatizer for aflatoxin and sulfa drugs. It includes a UV LED light source, the excitation wavelength of which is between 280 and 370nm, and uses a thin inner diameter tube transparent to ultraviolet light as the derivation reaction pool. The diameter is 0.10-0.35 mm, the length is 17-30 cm, and the volume of the derivation pool is 7-15 μL. The optical derivatizer of the present invention increases the fluorescence intensity of aflatoxin B1 by 5 times; the derivatizer is used for liquid chromatography post-column derivatization and flow injection analysis derivatization needs, including high performance liquid chromatography (HPLC) and ultra-high pressure liquid Trace aflatoxins and sulfonamides in samples were analyzed by UPLC.

The invention relates to a synthetic method of stable isotope labeled aminophenylsulfone. The method comprises the following steps: by taking stable isotope labeled p-nitro halogeno benzene as a raw material, carrying out nucleophilic substitution to generate stable isotope labeled 4, 4'-dinitro phenyl sulfide; oxidizing to obtain stable isotope labeled 4, 4'-dinitro diphenyl sulfone; and finally carrying out reaction with a reducing agent to obtain the stable isotope labeled aminophenylsulfone. Compared with the prior art, according to the stable isotope labeled aminophenylsulfone prepared by the invention simply separated and purified, the chemical purity reaches over 99% and the isotope abundance is 99%, so that the demand of aminophenylsulfone detection of forbidden sulfonamides in the field of food safety can be fully satisfied.