Reagent for analyzing types of dimethyl pyridine isomers as well as preparation method and analysis method thereof

Abstract

The invention relates to the field of chemical analysis, in particular to a reagent for analyzing types of dimethyl pyridine isomers as well as a preparation method and an analysis method of the reagent. The reagent comprises cyclodextrin, a soluble metal compound and a solvent; the analysis method comprises the following steps: S1, mixing a dimethyl pyridine molecule sample with a reagent to prepare a solution to be detected; s2, treating the solution to be detected by adopting an ionization device to generate compound ions, measuring the ion mobility or the ion collision cross section of the compound ions, and distinguishing the dimethyl pyridine isomers; the reagent for analyzing the types of the dimethyl pyridine isomers is simple in component, easy to obtain and low in cost; according to the analysis method, the problem that the types of the dimethyl pyridine isomers cannot be analyzed and identified by high performance liquid chromatography, gas chromatography, nuclear magnetic resonance and other methods is solved, the 2, 5-dimethyl pyridine and the 3, 5-dimethyl pyridine positional isomers can be rapidly analyzed and identified, and information of the dimethyl pyridine positional isomers is obtained.

Description

Technical Field

[0001] The invention relates to the field of chemical analysis, and in particular to a reagent for analyzing the types of dimethylpyridine isomers and a preparation method and an analysis method thereof. Background Art

[0002] Molecules are the basis of matter. Each molecule has its own unique composition and structure, which determine the physical and chemical properties of the molecule, and even its biological properties. Isomers are a special type of molecular structure, which refers to a class of substances with the same chemical formula but different chemical structures. They have the same molecular formula, but because of the different arrangements of atoms, their properties and activities are also different. The existence of isomers is due to the ability of carbon atoms in organic compounds to form different bonds and mutually exclusive configurations. Positional isomers refer to compounds with the same composition but different positions of substituents or functional groups on the carbon frame. These compounds are called positional isomers.

[0003] There are many different types of isomers in nature, and different isomers usually have significant effects on chemical and biological properties and performances, such as aminobiphenyl isomers, among which 4-aminobiphenyl is a human bladder carcinogen and 2-aminobiphenyl is a harmless compound without any cancer activity. There are many such examples, such as the S-configuration ethambutol has the effect of treating tuberculosis, while the R-configuration has a blinding effect, and the S-configuration ibuprofen has the effect of relieving fever and pain, while the R-configuration has no pharmacological activity.

[0004] Due to the extremely important role of molecular isomers, the identification and separation technology of positional isomers of small molecules has developed rapidly in recent years. Understanding the positional isomers in isomers, especially the positional structure in an important small molecule, is of great significance and value to various industries. In the past work, scientific and technological workers have developed many methods for measuring isomers, such as high performance liquid chromatography, gas chromatography, nuclear magnetic resonance and other methods; but the positional isomers in isomers are complex and diverse, and there is almost no method that can be used to analyze or separate all positional isomers. Therefore, research and development of new and more effective positional isomer analysis and separation is one of the hot areas that everyone is concerned about.

[0005] Pyridine and its derivatives are widely distributed in nature. Many plant components such as alkaloids contain pyridine ring compounds in their structures. Simple pyridine molecules and their derivatives also exist in coal tar and bone oil. They are extremely widely used, such as in the production of high value-added fine chemical products, and they occupy an important position in the pharmaceutical industry, pesticide industry and chemical industry. Lutidine is widely used as an intermediate in the pharmaceutical industry, dye industry, pesticide industry and polymer industry. In the pharmaceutical industry, lutidine is an important raw material for the synthesis of sulphuric acid, nicotinic acid, hydrocortisone, etc. It can also be an intermediate in pesticides, dyes, printing and dyeing auxiliaries, resins, etc. Summary of the invention

[0006] The purpose of the present invention is to provide a reagent with simple ingredients, low cost and the ability to quickly analyze lutidine isomers, as well as a preparation method and an analysis method thereof, in view of the deficiencies in the prior art.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] The first aspect of the present invention is to provide a reagent for analyzing the isomer types of lutidine, comprising: cyclodextrin, a soluble metal compound and a solvent.

[0009] Preferably, the cyclodextrin is α-cyclodextrin or an α-cyclodextrin derivative.

[0010] Preferably, the metal in the soluble metal compound includes at least one of divalent iron, cobalt and zinc.

[0011] Preferably, the solvent includes at least one of deionized water and an organic reagent.

[0012] More preferably, the organic reagent comprises at least one of methanol, ethanol, acetonitrile, ether, acetone, formic acid and acetic acid.

[0013] The second aspect of the present invention is to provide a method for preparing the above-mentioned reagent, comprising the steps of: weighing cyclodextrin and a soluble metal compound, dissolving them in a solvent respectively, and preparing them to a concentration of 1×10 -3 mol / L cyclodextrin mother solution and soluble metal compound mother solution; measure the cyclodextrin mother solution and the soluble metal compound mother solution, mix and dilute them to obtain the reagent.

[0014] The third aspect of the present invention is to provide a method for analyzing the types of lutidine isomers, the steps comprising:

[0015] S1, mixing the lutidine molecular sample with the above reagent to prepare a test solution;

[0016] S2. Treating the test solution with an ionization device to generate complex ions, measuring the ion mobility or ion collision cross section of the complex ions, and distinguishing the isomers of lutidine.

[0017] Preferably, in the test solution, the concentration of cyclodextrin molecules is 10 -10 mol / L-1mol / L; the concentration of soluble metal compounds is 10 -10 mol / L-1mol / L; the concentration of xylene pyridine molecules is 10 -10 mol / L-1mol / L.

[0018] Preferably, the complex ions include: [α-CD+LUT+Fe-H] + 、[α-CD+LUT+Co-H] + 、[α-CD+LUT+Zn-H] + At least one of .

[0019] Preferably, the lutidine molecular sample comprises at least one of 2,5-lutidine and 3,5-lutidine.

[0020] The present invention adopts the above technical solution, and has the following technical effects compared with the prior art:

[0021] The reagent components for analyzing the types of lutidine isomers of the present invention are simple, easy to obtain and low in cost; the analysis method of the present invention overcomes the difficulty that methods such as high performance liquid chromatography, gas chromatography, nuclear magnetic resonance and the like cannot analyze and identify the types of lutidine isomers, and can quickly analyze and identify the positional isomers of 2,5-lutidine and 3,5-lutidine, and obtain the positional isomer information of lutidine. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the molecular structure of positional isomers of dimethylpyridine.

[0023] Figure 2 Schematic diagram of the molecular structure of α-cyclodextrin.

[0024] Figure 3 This is the mass spectrum of a mixed solution of lutidine, α-cyclodextrin and a compound containing ferrous ions.

[0025] Figure 4 This is the ion migration spectrum of “ternary complex ions of two dimethylpyridine molecules-cyclodextrin-divalent iron ion”; among them, the black mark is the ternary complex ion of 2,5-dimethylpyridine-cyclodextrin-divalent iron ion, and the red mark is the ternary complex ion of 3,5-dimethylpyridine-cyclodextrin-divalent iron ion.

[0026] Figure 5 This is the mass spectrum of a mixed solution of lutidine, α-cyclodextrin and a compound containing cobalt ions.

[0027] Figure 6 This is the ion migration spectrum of “ternary complex ions of two dimethylpyridine molecules-cyclodextrin-divalent cobalt ions”; among them, the black mark is the ternary complex ion of 2,5-dimethylpyridine-cyclodextrin-divalent cobalt ions, and the red mark is the ternary complex ion of 3,5-dimethylpyridine-cyclodextrin-divalent cobalt ions.

[0028] Figure 7 This is the mass spectrum of a mixed solution of lutidine, α-cyclodextrin and a zinc ion-containing compound.

[0029] Figure 8 This is the ion migration spectrum of “ternary complex ions of two dimethylpyridine molecules-cyclodextrin-divalent zinc ions”; the red mark is the ternary complex ion of 2,5-dimethylpyridine-cyclodextrin-divalent cobalt ion, and the black mark is the ternary complex ion of 3,5-dimethylpyridine-cyclodextrin-divalent zinc ion. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0033] Example

[0034] This embodiment provides a method for analyzing the types of lutidine isomers, the steps comprising:

[0035] S1. Weigh ferrous chloride, cobalt chloride, zinc chloride and α-cyclodextrin, dissolve them in solvent (CH3OH:H2O=1:1) and prepare them into a concentration of 1×10 -3 mol / L ferrous chloride mother solution, cobalt chloride mother solution, zinc chloride mother solution and α-cyclodextrin mother solution;

[0036] 30 μL of ferrous chloride mother solution and 30 μL of α-cyclodextrin mother solution were respectively measured and mixed to obtain the reagent, the lutidine molecular sample was weighed and mixed with the reagent, and a diluent (methanol: water = 9:1) was added to dilute to obtain the test solution; the test solution containing divalent cobalt and the test solution containing divalent zinc were prepared according to the above method.

[0037] The concentrations of the soluble metal compound, α-cyclodextrin and the positional isomer of lutidine in the solution can be determined according to experimental requirements. In addition, the concentration of each compound in the mixed solution can be the same or different.

[0038] S2. The electrospray ion source (ESI) of a TIMS-TOF MS instrument (Bruker) was used to generate complex ions. The complex ions generated by ESI were analyzed by mass spectrometry and the ion mobility spectra of the complex ions were determined. Since the ions formed by different positional isomers and cyclodextrin and metal ions have different collision cross sections, they have different ion mobilities. The positional isomer information of the analyzed dimethylpyridine was obtained by comparative analysis.

[0039] The types of complex ions are shown in Table 1 ;

[0040] Table 1

[0041]

[0042] like Figure 3-8 As shown in Table 1, different lutidine isomers are clearly distinguished.

[0043] In summary, the reagent components for analyzing the types of lutidine isomers of the present invention are simple, easy to obtain and low in cost; the analysis method of the present invention overcomes the difficulty that high performance liquid chromatography, gas chromatography, nuclear magnetic resonance and other methods cannot analyze and identify the types of lutidine isomers, and can quickly analyze and identify the positional isomers of 2,5-lutidine and 3,5-lutidine, and obtain the positional isomer information of lutidine.

[0044] The above description is only a preferred embodiment of the present invention, and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A reagent for analyzing the isomer types of lutidine, characterized in that: include: Cyclodextrin, a soluble metal compound, and a solvent.

2. The reagent according to claim 1, characterized in that The cyclodextrin is α-cyclodextrin or an α-cyclodextrin derivative.

3. The reagent according to claim 1, characterized in that The metal in the soluble metal compound includes at least one of divalent iron, cobalt and zinc.

4. The reagent according to claim 1, characterized in that The solvent includes: at least one of deionized water and an organic reagent.

5. The reagent according to claim 4, characterized in that The organic reagent includes at least one of methanol, ethanol, acetonitrile, ether, acetone, formic acid and acetic acid.

6. A method for preparing a reagent as claimed in any one of claims 1 to 5, characterized in that: The steps include: weighing cyclodextrin and a soluble metal compound, dissolving them in a solvent respectively, and preparing a concentration of 1×10 -3 mol / L cyclodextrin mother solution and soluble metal compound mother solution; measure the cyclodextrin mother solution and the soluble metal compound mother solution, mix and dilute them to obtain the reagent.

7. A method for analyzing the isomers of lutidine, characterized in that the steps include: S1. Mixing the lutidine molecular sample with the reagent according to any one of claims 1 to 5 to prepare a test solution; S2. Treating the test solution with an ionization device to generate complex ions, measuring the ion mobility or ion collision cross section of the complex ions, and distinguishing the isomers of lutidine.

8. The analysis method according to claim 7, characterized in that In the test solution, the concentration of cyclodextrin molecules is 10 -10 mol / L-1mol / L; the concentration of soluble metal compounds is 10 -10 mol / L-1mol / L; the concentration of xylene pyridine molecules is 10 -10 mol / L-1mol / L.

9. The analysis method according to claim 7, characterized in that The complex ions include: [α-CD+LUT+Fe-H] + 、[α-CD+LUT+Co-H] + 、[α-CD+LUT+Zn-H] + At least one of .

10. The analysis method according to claim 7, characterized in that The lutidine molecular sample includes at least one of 2,5-lutidine and 3,5-lutidine.

Images