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CN-122016692-A - Color reagent for rapidly determining lignan content and preparation method thereof

CN122016692ACN 122016692 ACN122016692 ACN 122016692ACN-122016692-A

Abstract

The invention relates to the technical field of analytical chemistry detection, in particular to a color reagent for rapidly determining the content of lignans and a preparation method thereof, wherein the color reagent comprises a liquid component and a solid component dispersed in the liquid component, the liquid component comprises the following components by volume, the color reagent comprises an acidic ethanol solution of 2, 4-dinitrophenylhydrazine with the concentration of 5-10 mmol/L, a nano signal enhancer comprises a surface modified gold nano rod sol with the concentration of 3-8 nM, a catalytic oxidant comprises iron (III) porphyrin with the concentration of 0.05-0.15 mmol/L, a dispersion stabilizer comprises polyethylene glycol 400 with the volume fraction of 1-3%, a solvent system comprises a mixed solvent of buffer solution with the pH value of 2.0-3.0 and ethanol, and the solid component comprises lignan molecularly imprinted polymer microspheres with the concentration of 0.5-2.0 g/L in the color reagent. The invention is convenient for detecting lignans, has high sensitivity, provides specific recognition capability for the molecularly imprinted polymer, and realizes rapid, high-sensitivity and high-selectivity colorimetric detection of lignans.

Inventors

  • LI XIANG
  • ZENG ZHIWEN
  • LIANG ZHONGHOU
  • HE LINGZHI
  • CHEN JUANJUAN
  • DENG YE
  • MIN YANG
  • LI MI

Assignees

  • 湖南环境生物职业技术学院

Dates

Publication Date
20260512
Application Date
20260319

Claims (10)

  1. 1. A color reagent for rapid determination of lignan content, comprising a liquid component and a solid component dispersed therein, wherein the liquid component comprises the following components by volume: A color reagent, namely an acidic ethanol solution of 2, 4-dinitrophenylhydrazine with the concentration of 5-10 mmol/L; a nano signal enhancer, namely surface modified gold nanorod sol with the concentration of 3-8 nM; catalytic oxidizer, iron (III) porphyrin with concentration of 0.05-0.15 mmol/L; A dispersion stabilizer, namely polyethylene glycol 400 with the volume fraction of 1-3%; A solvent system, which is a mixed solvent of buffer solution with pH value of 2.0-3.0 and ethanol; The solid component is lignan molecularly imprinted polymer microsphere, and the concentration of the solid component in the color developing agent is 0.5-2.0 g/L.
  2. 2. The color reagent for rapidly determining lignan content according to claim 1, wherein the surface-modified gold nanorods are gold nanorods with surfaces modified by polyvinylpyrrolidone and have an aspect ratio of 3.5-4.5.
  3. 3. The color reagent for rapidly determining the lignan content according to claim 2, wherein the lignan molecularly imprinted polymer microsphere is prepared by a precipitation polymerization method by taking schisandra chinensis methyl as a template molecule, methacrylic acid as a functional monomer and ethylene glycol dimethacrylate as a cross-linking agent.
  4. 4. The color reagent for rapid determination of lignan content according to claim 1, wherein the buffer is a citric acid-disodium hydrogen phosphate buffer or a citric acid-sodium citrate buffer.
  5. 5. The color reagent for rapid determination of lignan content according to claim 1, wherein the volume ratio of ethanol to buffer in the acidic ethanol solution is 1:3 to 1:5.
  6. 6. A method for preparing a color developing agent for rapidly determining lignan content, which is used for preparing the color developing agent according to any one of claims 1 to 5, characterized in that the method comprises the following steps: a) Preparing a liquid phase base solution, namely dissolving 2, 4-dinitrophenylhydrazine in an acidic ethanol solution consisting of a buffer solution with the pH value of 2.0-3.0 and absolute ethanol according to the volume ratio (3-5): 1 under the light-shielding condition, and stirring until the solution is completely dissolved to obtain a color development main agent solution; b) Constructing a nano reinforced liquid phase, namely adding the surface modified gold nanorod sol into the liquid phase base liquid obtained in the step S1 under the stirring condition, and then performing ultrasonic treatment to obtain a mixed liquid A; c) Adding a catalytic oxidant, namely adding iron (III) porphyrin into the mixed solution A obtained in the step S2 under the stirring condition, and uniformly mixing to obtain a mixed solution B; d) And (3) solid-phase dispersion and curing, namely adding the lignan molecularly imprinted polymer microspheres into the mixed solution B obtained in the step (S3) under the stirring condition of 50-200 rpm, continuously stirring to uniformly disperse the microspheres, and then standing and curing for 20-28 hours under the environment of 2-8 ℃ to obtain the color reagent.
  7. 7. The method for preparing a color developing agent for rapidly determining lignan content according to claim 6, wherein in the step a), the condition of stirring and dissolving is stirring at a rotation speed of 300-500 rpm for 20-40 minutes at 20-30 ℃.
  8. 8. The method for preparing a color reagent for rapidly determining lignan content according to claim 6, wherein in the step b), the power of the ultrasonic treatment is 200-400W and the treatment time is 10-20 minutes, and the surface-modified gold nanorod sol is previously mixed with a part of the polyethylene glycol 400 in a calculated amount and is subjected to ultrasonic treatment for 5-10 minutes at 100-200W power before being added.
  9. 9. The method of preparing a color reagent for rapidly determining lignan content according to claim 6, wherein in the step c), the mixing is performed under ice bath or cold water bath conditions, the stirring speed is 200-400 rpm, and the mixing time is 10-20 minutes.
  10. 10. The method of preparing a color reagent for rapidly determining lignan content according to claim 6, wherein in the step d), the lignan molecularly imprinted polymer microsphere is dried in vacuum at 40-60 ℃ for 2-4 hours in advance before being added, and is stirred for 45-75 minutes at a rotation speed of 100-200 rpm after the lignan molecularly imprinted polymer microsphere is added to ensure uniform dispersion.

Description

Color reagent for rapidly determining lignan content and preparation method thereof Technical Field The invention relates to the technical field of analytical chemistry detection, in particular to a color reagent for rapidly determining the content of lignans and a preparation method thereof. Background Lignans are an important class of bioactive components that are widely found in plants. In the fields of medicines, health-care products, foods and the like, the method for rapidly and accurately measuring the lignan content in raw materials or products is a key link of quality control and efficacy evaluation. Currently, the primary assay methods include chromatography and spectroscopy. Chromatography, such as high performance liquid chromatography, spectrometry, such as ultraviolet-visible spectrophotometry, while accurate and split, relies on expensive instrumentation, is complex and time consuming to operate, and is difficult to meet the rapid screening requirements of on-site or large-scale samples. Traditional spectrophotometry represented by the vanillin-concentrated sulfuric acid method is relatively simple to operate, but has significant drawbacks: Firstly, the color reaction usually requires long-time heating, such as boiling water bath for more than 30 minutes, and the efficiency is low; Secondly, the reaction selectivity is poor, and the common components such as polyphenol, flavone, pigment and the like in the sample are easy to interfere, so that the result is high in false; thirdly, the used concentrated sulfuric acid has strong corrosiveness and oxidability, potential safety hazard exists, and the stability of the color development liquid is poor, so that the measurement time is required to be strictly controlled. Therefore, the development of the special color reagent with rapid reaction, high selectivity, safe operation and good stability has important significance for realizing high-flux and rapid quantitative analysis of lignans. Disclosure of Invention In order to solve the problems, the invention provides a color reagent for rapidly determining the content of lignans and a preparation method thereof, wherein the color reagent combines specific chemical reaction, nano plasma resonance enhancement effect and molecular recognition technology, the color reaction is rapid under the action of a bionic catalyst, the lignans can be conveniently detected, the sensitivity is high, and the introduction of a molecular imprinting polymer provides specific recognition capability, so that the rapid, high-sensitivity and high-selectivity colorimetric detection of lignans is realized. In order to achieve the above object, the embodiment of the present invention provides the following technical solutions: in a first aspect, the present invention provides a color reagent for rapidly determining lignan content, comprising a liquid component and a solid component dispersed therein, wherein the liquid component comprises the following components by volume: A color reagent, namely an acidic ethanol solution of 2, 4-dinitrophenylhydrazine with the concentration of 5-10 mmol/L; a nano signal enhancer, namely surface modified gold nanorod sol with the concentration of 3-8 nM; catalytic oxidizer, iron (III) porphyrin with concentration of 0.05-0.15 mmol/L; A dispersion stabilizer, namely polyethylene glycol 400 with the volume fraction of 1-3%; A solvent system, which is a mixed solvent of buffer solution with pH value of 2.0-3.0 and ethanol; The solid component is lignan molecularly imprinted polymer microsphere, and the concentration of the solid component in the color developing agent is 0.5-2.0 g/L. As a further scheme of the invention, the surface modified gold nanorods are gold nanorods with surfaces modified by polyvinylpyrrolidone, and the length-diameter ratio is 3.5-4.5. As a further scheme of the invention, the lignan molecularly imprinted polymer microsphere is prepared by a precipitation polymerization method by taking schisandra chinensis methyl as a template molecule, methacrylic acid as a functional monomer and ethylene glycol dimethacrylate as a cross-linking agent. As a further aspect of the invention, the buffer is a citric acid-disodium hydrogen phosphate buffer or a citric acid-sodium citrate buffer. As a further aspect of the present invention, in the acidic ethanol solution, the volume ratio of ethanol to buffer is 1:3 to 1:5. In a second aspect, the present invention provides a method for preparing a color developing agent for rapidly determining lignan content, comprising the steps of: a) Preparing a liquid phase base solution, namely dissolving 2, 4-dinitrophenylhydrazine in an acidic ethanol solution consisting of a buffer solution with the pH value of 2.0-3.0 and absolute ethanol according to the volume ratio (3-5): 1 under the light-shielding condition, and stirring until the solution is completely dissolved to obtain a color development main agent solution; b) Constructing a nano rein