39 results about "Paper chromatography" patented technology

The invention belongs to the technical field of food analysis, and more specifically provides a simultaneous detection method of plurality of dopants in milk powder. According to the simultaneous detection method of plurality of dopants in milk powder, a raman spectrometer is used, and the dopants comprise melamine, dicyandiamide, and sodium sulfocyanate. The simultaneous detection method comprises steps of preparation of chitosan-SERS paper chromatography, pretreatment of milk powder samples, separation of paper chromatography, and SERS detection. A preparation method of self-made SERS paper chromatography is simple; cost is low; separation effect is excellent; the raman spectrometer is convenient to carry; the simultaneous detection method is suitable for on-site rapid detection; the pretreatment process of the milk powder samples is simple, and only filtering is needed; an obtained non-blank spectrogram is compared with the standard raman spectrograms of the above three dopants point by point so as to determine whether a detected sample contains the dopants; no reference experiment is needed; the toxicity of a selected developing solvent is relatively low; the developing solvent is friendly to the environment; separation of the dopants is impossible to realize with other developing solvents; separation detection time of the samples is shorter than 25min; and on-site rapid detection can be realized.

A high-throughput screening method for an L-aspartate beta-decarboxylase producing strain is disclosed. The method includes 1) subjecting microorganisms in a sample to enrichment culture and primary separation by adopting an enrichment culture medium, 2) inoculating single colonies obtained through separation from a plane plate to a 96-micropore plate primary screening semisolid medium and performing primary screening to obtain L-aspartate beta-decarboxylase producing strains, 3) inoculating the strains obtained through primary screening to a 24-prore plate, performing liquid culturing, and performing secondary screening to obtain the L-aspartate beta-decarboxylase producing strain with high yield by combining paper chromatography, and 4) subjecting the high-yield strain obtained through secondary screening to fermentation in a shake flask, and determining enzyme activity by combining an oxidation coloration process. The method is suitable for high-throughput screening of the L-aspartate beta-decarboxylase producing strain. The strain obtained through screening is alkali-resistant, thus avoiding tedious pH value controlling steps in a cell production processes. References are provided for high-throughput screening of producing strains bio-enzymes of the same kind.

The invention relates to a new thorium chromogenic agent m-fluoroazophosphine and its synthesis and application, belonging to the technical field of organic reagent synthesis and application. The synthesis method adopts nitration hydrolysis, direct reduction phosphonation, diazotization coupling and other reactions to obtain the crude m-fluoroazofluorophosphine, which is purified by acidification and developed with 25% ammonia water: 5% sodium citrate=2:5. The pure product is obtained by paper chromatography, and has the advantages of short reaction time, complete reaction and simple synthesis process. In the photometric analysis and determination of thorium (IV) by the chromogenic agent, the surfactant hexadecylpyridine bromide is introduced, and the system has a significant sensitization effect after being purified by n-butanol, and has high sensitivity and selectivity , and has certain application value in the analysis fields such as environment and food.

A method and application for signal immobilization detection of a nanomaterial colorimetric sensing system based on a chromatography paper-integrating sphere, relating to the field of nanomaterial-based colorimetric detection methods, a traditional nanomaterial colorimetric sensing system and a target After the interaction and color development, take an appropriate amount of the mixed dispersion droplets on the chromatography paper at the pre-termination time to form regular circular spots. After natural drying, use the chromatography paper as a blank, and place the sample in a UV-visible spectrophotometer. On the attachment of the integrating sphere, the area to be measured is aligned with the light spot to collect the absorption spectrum, and finally the quantitative analysis of the target is carried out through data processing. The invention adopts the method of combining chromatographic paper and integrating sphere, which not only fixes the signal of the nanomaterial in dynamic aggregation, but also overcomes the disadvantage that the conventional paper analysis technology is difficult to accurately measure. At the same time, the determination is not limited by time, and the obtained results are more reliable and accurate.