14 results about "Ninhydrin" patented technology

The invention relates to the technical field of forensic science criminal affairs, in particular to the field of special laboratory trace inspection, and more particularly relates to a reagent appearance fingerprint temperature control method applied to paper. A reagent appearing fingerprint temperature control method applied to paper is characterized by comprising the following steps that S1, an experiment is conducted in the same experiment environment; s2, taking indandione as a fingerprint appearing reagent, and dividing the fingerprint appearing reagent into a group A; ninhydrin is used as a fingerprint development reagent and is divided into a group B; s3, respectively carrying out the group A experiment and the group B experiment, gradually raising the temperature to carry out a fingerprint showing experiment in a short time when the experiment setting requirement is met, and judging the fingerprint showing effect, and recording the optimal baking temperature interval and the corresponding time; and S4, aiming at an experiment result, when a fingerprint display effect picture is obtained, performing standard photographing on the fingerprint, so that under a normal observation distance, pixel points cannot be distinguished by naked eyes, and potential fingerprints can be completely displayed and are regarded as clear and complete.

The application discloses a method for rapidly detecting amino acid content, which comprises the following steps: firstly, subjecting a substrate such as earthworm protein powder to microbial fermentation; and then rapidly detecting the free amino acid content in the fermentation liquor by means of an optimized indantrione color developing method (boiling water bath for 2-3 minutes, determination at 570 nm). The rapid detection technology is deeply combined with a strain screening process, and the amino acid production capacity of bacillus, lactic acid bacteria and mixed strains in a ratio of F14:MLB36:LAB2 (2:3:3) is utilized, so that high-quality strains capable of significantly improving the amino acid yield are directly screened. The application overcomes the problems of low efficiency and high cost of a traditional detection method, and provides a solution for efficient biological manufacturing and rapid detection of amino acids.

The invention discloses a method for synchronously detecting L-asparagine monohydrate and L-alanyl-L-glutamine in an assisted reproduction culture solution. The L-asparagine monohydrate and the L-alanyl-L-glutamine in the assisted reproduction culture solution are used as a detection reagent. According to the method, a pretreatment mode of combining protein precipitation with diluted hydrochloric acid extraction is adopted, a target object is separated through ion exchange chromatography, and a ninhydrin post-column derivatization technology is adopted to establish an external standard method quantitative analysis system. The method has the following advantages: (1) synchronous and efficient separation and accurate quantification of two amino acid substances are realized; (2) methodology verification shows that good repeatability (RSD (Relative Standard Deviation) is 1.05) and high sensitivity (the detection results of L-asparagine monohydrate and L-alanyl-L-glutamine are 0.00038 mg / mL and 0.00036 mg / mL respectively); (3) the operation is simple and convenient, and the single analysis time is about 60 minutes; and (4) the recovery rate is stabilized in a range of 93%-105%. The method provides a reliable analysis means for quality control of the assisted reproduction culture solution, and is particularly suitable for quantitative determination of key amino acid components in the assisted reproduction culture solution.

The invention relates to the technical field of biochemical sensing, in particular to an aminoglycoside antibiotic dual-mode visual detection card and a preparation method and application thereof, and the detection card is composed of two parts: an aminoglycoside antibiotic dual-mode labeling reagent and qualitative filter paper. The dual-mode labeling reagent is formed by self-assembling ninhydrin and lanthanide metal ions, and is used for providing a color development / ratio fluorescence dual-mode detection signal; the qualitative filter paper is used for efficient adsorption and enrichment of aminoglycoside antibiotics, and can significantly enhance color development and fluorescence signals. The detection card provided by the invention can realize double-mode (color development and fluorescence) visual detection and identification of aminoglycoside antibiotics only by using one labeling reagent, and is good in response selectivity, high in sensitivity, strong in anti-interference capability, mild in condition and easy to popularize. The detection accuracy and reliability can be remarkably improved through cross validation of double-signal-channel visual detection results.

The application relates to the field of polyamide material analysis, and discloses application of an indantrione color developing reagent in determination of polyamide hydrolysis products and a method for determining the content of the polyamide hydrolysis products, wherein the indantrione color developing reagent contains an indantrione-ethylene glycol solution and an acetic acid-sodium acetate buffer solution. The application provided in the application adopts ethylene glycol as a single solvent of the indantrione, effectively inhibits oxidative degradation of the indantrione under high-temperature color developing conditions, and enables uniform color development of oligomers. The application does not add antioxidants, avoids interference with color developing reactions, is accurate and reliable in determination, is simple in preparation due to the single solvent, has a long storage time under light shielding at 4 DEG C, and can not only accurately determine monomers of polyamides and dimers to heptamers of the monomers, but also accurately determine various polyamide hydrolysis products, and has a good linear relationship.

The invention discloses an analysis method for verifying cleaning residues of histidine on the surface of pharmaceutical production equipment, which comprises the following steps: mixing a sample containing histidine with a ninhydrin aqueous solution, and reacting under a heating condition to generate a derivative with specific absorption in an ultraviolet region; measuring the absorbance value of the obtained reaction liquid at the wavelength of 570nm by adopting an ultraviolet-visible spectrophotometric method; and comparing the measured absorbance value with a histidine concentration-absorbance standard curve, and calculating to obtain the content of histidine in the sample. According to the present invention, through the ninhydrin derivatization reaction, the non-ultraviolet absorption histidine is converted into the strong ultraviolet absorption substance, and the characteristic absorption peak exists at the 570 nm position, such that the detection sensitivity is substantially improved, the interference of other possible residual substances is effectively avoided, and the microgram / mL level low concentration residue can be effectively detected; the detection method is simple and convenient to operate, low in cost and high in reliability.

The application discloses a preparation method of a medical intermediate (R)-7-ethyl camptothecin, and relates to the field of chemical medicine synthesis. The application comprises the following contents: (R)-4-ethyl-4-hydroxy-7,8-dihydro-1H-pyrano[3,4-f]indolizine-3,6,10(4H)-trione (formula A) and 1-(2-aminophenyl)propan-1-one (formula B) are used as main raw materials, a target compound (R)-7-ethyl camptothecin is obtained through reaction in an organic solvent under the action of a catalyst. The application provides a novel preparation method of the medical intermediate (R)-7-ethyl camptothecin, and the preparation method is simple, stable, high in yield, and suitable for industrial production.

This invention belongs to the field of analytical chemistry, specifically relating to an analytical detection method for related substances in dihydropyridine compounds. Specifically, it includes adding ninhydrin to a test solution containing dihydropyridine compounds to prepare a test solution, and then using liquid chromatography-mass spectrometry (LC-MS) to detect the content of compound I in the dihydropyridine compounds. The analytical detection method provided by this invention has good precision, high accuracy, high sensitivity, good linearity, good stability of the test solution, low detection limit, and accurate detection results.

The invention discloses a determination kit and a determination method for the total amount of free amino acids in tea leaves, and belongs to the technical field of food detection. In order to solve the problems of low detection efficiency, high cost and large sample demand of the existing method for determining the total amount of free amino acids in tea leaves, the determination kit provided by the invention comprises a solution A (1 mg / ml glutamic acid standard solution), a solution B (phosphate buffer with pH of 8.0) and a solution C (2% ninhydrin solution containing 0.8 mg / mL stannous chloride). The corresponding determination method comprises the steps of sample treatment, dry matter content determination, standard curve making, sample detection and content calculation. The microplate reader is adopted for detection, a plurality of samples can be measured at the same time at one time, the detection time is only about 5 min, the required sample amount is only 50 mg, the reagent dosage is greatly reduced, the detection efficiency is remarkably improved, the detection cost is reduced, and the method is suitable for rapid detection of a large batch of tea samples and has important significance on tea quality judgment.

The invention relates to a rapid colorimetric detection method and kit for the crosslinking state of biological tissues. The method comprises the following steps: preparing a color developing system solution containing ninhydrin, dipping a porous base material, and drying to obtain color developing test paper; the method comprises the following steps: providing standard biological tissue samples treated in different cross-linking states, calibrating the cross-linking states of the standard biological tissue samples by adopting thermal shrinkage temperature and / or mechanical property indexes, enabling a color result formed by the standard samples in the same color development mode as a to-be-detected sample to correspond to the cross-linking states, and establishing a standard colorimetric card with color gradation; the method comprises the following steps: soaking a to-be-detected biological tissue subjected to cross-linking treatment in a buffer solution to extract residual free amino groups, dropwise adding supernate onto color developing test paper, heating and developing, visually comparing with a standard colorimetric card under the same illumination condition, and outputting a cross-linking degree judgment result. The kit comprises color developing test paper, a standard colorimetric card and a detection interpretation instruction. The scheme is simple and convenient to operate, does not need complex instruments, and is suitable for on-site rapid grading and inter-batch consistency control.

The invention discloses a sarcosine-substituted neuropeptide FF analogue as well as a preparation method and application thereof, and relates to the technical field of medicines, the amino acid sequence of the analogue is Ac-Phe-Leu-Phe-(Sar)-Pro-Gln-Arg-Ph-NH2, Sar is sarcosine, and the amino acid sequence of the analogue is Ac-Phe-Leu-Phe-(Sar)-Pro-Gln-Arg-Ph-NH2. The molecular formula of the analogue is as follows: the theoretical average molecular weight is 1066.25. Sarcosine is accurately introduced to the fourth site of a peptide chain through a solid-phase synthesis method, N-methylation modification is formed, and incision enzyme degradation is specifically resisted on the premise that a receptor binding structure is not changed; and then N-terminal acetylation end capping is combined to construct a dual protection barrier aiming at aminopeptidase and incision enzyme, so that the in-vivo stability of the analogue is remarkably enhanced. The optimized synthesis process comprises ninhydrin monitoring, a specific lysate formula and efficient purification steps, high purity, structural accuracy and remarkable anti-inflammatory activity of the product are ensured, and a candidate drug with clinical transformation potential is provided for treating autoimmune skin diseases such as psoriasis.

The invention discloses a method for rapidly detecting the content of amino acid, which comprises the following steps: firstly, carrying out microbial fermentation on substrates such as earthworm protein powder, and rapidly determining the content of free amino acid in fermentation liquor through an optimized ninhydrin color development method (boiling water bath for 2-3 minutes, 570nm determination). A rapid detection technology and a strain screening technology are deeply fused, and high-quality strains capable of remarkably improving the yield of amino acid are directly screened out through the amino acid production capacity of bacillus, lactic acid bacteria and mixed strains according to the ratio (F14: MLB36: LAB2 is 2: 3: 3). The problems that a traditional detection method is low in efficiency and high in cost are solved, and a solution is provided for efficient biological manufacturing and rapid detection of amino acid.

The invention relates to the technical field of amino acid analysis and detection, and particularly discloses a method for synchronously detecting main components of amino acid and impurity amino acid. Comprising the following steps: preparing a mobile phase solution which comprises a mobile phase B1 to a mobile phase B5; preparing a ninhydrin reaction solution and a ninhydrin buffer solution; carrying out gradient elution on a to-be-detected sample on a cation exchange chromatographic column by using the mobile phase solution, and separating the amino acid main component from the impurity amino acid on the chromatographic column; mixing an effluent component subjected to chromatographic separation, a ninhydrin reaction solution and a ninhydrin buffer solution, and carrying out post-column derivatization reaction; and performing optical detection on a product of the derivatization reaction, and performing qualitative and quantitative analysis on main components of the amino acid and impurity amino acid according to a detection signal. According to the method disclosed by the invention, qualitative and quantitative analysis of main target amino acids and one or more impurity amino acids in a sample is synchronously completed in one-time sample injection analysis.

The application relates to the technical field of medical materials, in particular to a dyeing agent for endoscopic surgery and a preparation method and application thereof. The dyeing agent is an acetyl-GPLGIRG-ninhydrin enzyme-activated precursor, the acetyl-GPLGIRG-ninhydrin enzyme-activated precursor is obtained by the reaction of acetylated GPLGIRG polypeptide and ninhydrin, and the ninhydrin is connected to the carbon end of the acetylated GPLGIRG polypeptide. The specific cross-linking reaction of the ninhydrin component with the amino group of the protein, the biochemical difference of the diseased tissue and the normal tissue in the microstructure, the rapid, clear and persistent targeted blue marking of the diseased area are realized. Not only the problem that the traditional dyeing agent cannot specifically mark the disease is solved, but also the cross-linking characteristic is used, the "cushion" formed by the lifting liquid under the mucosa is more stable and persistent, and double advantages are provided for the endoscopic surgery.