阅读说明：本技术 一种区分α-萘酚及其同分异构体β-萘酚的方法 (Method for distinguishing alpha-naphthol and beta-naphthol isomers thereof ) 是由 胡刚 陈卓 张兰兰 于 2020-11-22 设计创作，主要内容包括：一种区分α-萘酚及其同分异构体β-萘酚的方法,其特征在于：应用“H-2SO-4-KIO-3-[NiL](ClO-4)-2-丙二酸-H-2O-2”化学振荡体系作为区分溶液,根据α-萘酚及β-萘酚对该体系振荡的影响不同,从而实现α-萘酚及β-萘酚的区分。本发明所涉及的区分方法所提供的电位振荡图谱具有直观性,可以方便快捷的区分出α-萘酚及β-萘酚,而且设备简单、准确度高、易于操作和观察。(A method for distinguishing alpha-naphthol and beta-naphthol, an isomer thereof, is characterized in that: application of "H 2 SO 4 ‑KIO 3 ‑[NiL](ClO 4 ) 2 -malonic acid-H 2 O 2 The chemical oscillation system is used as a distinguishing solution, and the distinguishing of alpha-naphthol and beta-naphthol is realized according to different influences of alpha-naphthol and beta-naphthol on the oscillation of the system. The potential oscillation spectrum provided by the distinguishing method has intuition, can conveniently and quickly distinguish alpha-naphthol and beta-naphthol, and has the advantages of simple equipment, high accuracy and easy operation and observation.)

1. A method for distinguishing alpha-naphthol and beta-naphthol, an isomer thereof, is characterized in that:

preparing a solution of a sample to be distinguished by using ethanol as a solvent;

application of "H₂SO₄ - KIO₃ - [NiL](ClO₄)₂ -malonic acid-H₂O₂The chemical oscillation system is used as a distinguishing solution, a potential oscillation spectrum of the potential of the chemical oscillation system along with the change of time is recorded, solutions of alpha-naphthol or beta-naphthol to be distinguished samples are respectively added into two groups of distinguishing solutions at any stable potential lowest point generated by oscillation, and the distinguishing of the samples to be distinguished is realized according to different influences of the samples to be distinguished on the chemical oscillation system: if the chemical oscillation is inhibited after the solution to be distinguished is added, the solution is passed through a long sectionAfter the inhibition time, the oscillation is recovered, and the added sample to be distinguished is alpha-naphthol; if the chemical oscillation is inhibited after the solution to be distinguished is added, and the oscillation is recovered after a short inhibition time, the added sample to be distinguished is beta-naphthol;

[NiL](ClO₄)₂wherein L is 5, 7, 7, 12, 14, 14-hexamethyl-1, 4, 8, 11-tetraazacyclotetradec-4, 11-diene; the molar concentration of each component in the distinguishing solution is as follows: 0.0246468-0.025mol/L sulfuric acid, 0.0175-0.021mol/L potassium iodate, [ NiL](ClO₄)₂6.4875×10^-4-8.65×10^-4mol/L, 0.125-0.165mol/L of malonic acid and 1.35-1.52mol/L of hydrogen peroxide.

2. The discrimination method according to claim 1, characterized in that: the molar concentration of each component in the solution is 0.025mol/L sulfuric acid, 0.01855mol/L potassium iodate and [ NiL ]](ClO₄)₂ 8.65×10^-4mol/L, 0.15mol/L of malonic acid and 1.5mol/L of hydrogen peroxide.

3. The discrimination method according to claim 1, characterized in that: the stable potential lowest point generated by oscillation is any one of the 3 rd to 25 th potential lowest points generated by oscillation.

4. The discrimination method according to claim 1, characterized in that: the distinguishable concentration range of the sample to be distinguished in the distinguishing solution is 2.5X 10^-6-1×10^-5mol/L。

Technical Field

The invention relates to a distinguishing method, in particular to a tetraazacyclotetradecadiene nickel complex [ NiL ]](ClO₄)₂ A catalytic chemical oscillation system is used for distinguishing isomers of alpha-naphthol and beta-naphthol, and a ligand L is 5, 7, 7, 12, 14, 14-hexamethyl-1, 4, 8, 11-tetraazacyclotetradecyl-4, 11-diene, belonging to the field of qualitative analytical chemistry.

Background

Alpha-naphthol and beta-naphthol are isomers of naphthol, and each other plays a very important role in their respective fields. α -naphthol, molecular formula: c₁₀H₈The O, alpha-naphthol can be used as a raw material of the pesticide carbaryl, and can be used for preparing a preservative and a medicament for resisting mild rheumatism in the pharmaceutical industry. It is also an effective antioxidant for many aldehydes, mineral oil and vegetable oil, is widely used for synthesizing perfumes, rubber antioxidants and color couplers of color cinematographic films, and is a basic raw material for organic synthesis industry, pharmaceutical industry and dye industry. It is also used for producing plastics, rubber anti-ageing agent, colour film and colour coupler, etc. Beta-naphthol, molecular formula: c₁₀H₈O, beta-naphthol is an important organic raw material and dye intermediateThe product can be used for preparing tobias acid, butyric acid and beta-naphthol-3-formic acid, and can be used for preparing antioxidant D, antioxidant DNP and other antioxidants, organic pigment and bactericide. Also used for producing dyes such AS acid orange Z, acid mordant black T, naphthol AS-SW, reactive brilliant orange X-GN, neutral black BGL, direct copper salt blue 2R and the like. Used as a reagent for measuring sulfanilamide and arylamine substances by thin layer chromatography. The method is used for improving cathode polarization, refining crystallization and reducing pores in acid tin plating.

Because alpha-naphthol and beta-naphthol, an isomer of alpha-naphthol, belong to positional isomers, have the same molecular formula and similar structure, so that some physical and chemical properties of alpha-naphthol and beta-naphthol are similar, the alpha-naphthol and the isomer of beta-naphthol are difficult to distinguish, and the analysis of the given character brings difficulty. The methods for detecting alpha-naphthol and beta-naphthol as isomers thereof reported at present mainly comprise thin-layer chromatography, gas chromatography, spectrophotometry and high performance liquid chromatography. However, the identification method for distinguishing the two has not been reported, so that it is necessary to find a qualitative analysis method with good distinguishing effect, simple and fast operation and easily judged result. Both of them are shown in structural formula (I)

Alpha-naphthol beta-naphthol

Alpha-naphthol and beta-naphthol structures of formula (I)

Disclosure of Invention

The invention aims to provide a novel, convenient and quick distinguishing method for alpha-naphthol and beta-naphthol, namely application of [ NiL](ClO₄)₂The method for distinguishing alpha-naphthol from beta-naphthol by using a catalytic chemical oscillation system is an electrochemical oscillation system method developed on the basis of the acute response of the complex-catalyzed chemical oscillation system to alpha-naphthol and beta-naphthol. Specifically, the samples (alpha-naphthol and beta-naphthol) to be distinguished with the same concentration are added respectivelyAnd (3) entering two groups of chemical oscillation systems, and realizing the distinction of the samples to be distinguished according to the different influences of the samples to be distinguished on the chemical oscillation systems: if the chemical oscillation is inhibited after the solution to be distinguished is added, and the oscillation is recovered after a long inhibition time, the added sample to be distinguished is alpha-naphthol; if the chemical oscillation is inhibited after the solution to be distinguished is added, and the oscillation is recovered after a short inhibition time, the added sample to be distinguished is beta-naphthol; the invention has short sample processing time, simple and easily controlled measuring conditions and convenient popularization and application.

The invention solves the technical problem and adopts the following technical scheme:

the invention provides a distinguishing method for alpha-naphthol and beta-naphthol, which is characterized by comprising the following steps:

preparing a solution of a sample to be distinguished by using ethanol as a solvent;

application of "H₂SO₄ - KIO₃ - [NiL](ClO₄)₂ -malonic acid-H₂O₂The chemical oscillation system is used as a distinguishing solution, a potential oscillation spectrum of the chemical oscillation system is recorded, solutions of alpha-naphthol and beta-naphthol to be distinguished samples are respectively added into two groups of distinguishing solutions (the chemical oscillation systems) at any stable potential lowest point, and qualitative analysis of the samples to be distinguished is realized according to different influences of the samples to be distinguished on the chemical oscillation system: if the chemical oscillation is inhibited after the solution to be distinguished is added, and the oscillation is recovered after a long inhibition time, the added sample to be distinguished is alpha-naphthol; if the chemical oscillation is inhibited after the solution to be distinguished is added, and the oscillation is recovered after a short inhibition time, the added sample to be distinguished is beta-naphthol.

The stable potential lowest point generated by oscillation is any one of the 3 rd to 25 th potential lowest points generated by oscillation.

The tetraazacyclotetradecadiene nickel complex is [ NiL](ClO₄)₂Wherein ligand L is 5, 7, 7, 12, 14, 14-hexamethyl-1, 4, 8, 11-tetraazacyclotetradec-4, 11-diene. [ NiL ]](ClO₄)₂The structure is as shown in formula (II)Shown in

Structural formula (II) [ NiL](ClO₄)₂Structure of (1)

The structure of the complex is very similar to that of key structure porphyrin ring of myoglobin, hemoglobin, chlorophyll and some metalloenzymes in a living body, and the structure is expressed by [ NiL](ClO₄)₂The catalyzed chemical oscillatory reaction is similar to biochemical oscillations within plant and animal cells. Therefore, the system has stable amplitude, long oscillation life and sharp response to alpha-naphthol and beta-naphthol.

[NiL](ClO₄)₂The preparation method comprises the following two steps: 1) preparation of L.2 HClO₄(ii) a 2) From L.2 HClO₄Preparation of [ NiL](ClO₄)₂。

1) Preparation of L.2 HClO₄：

98.5mL of ethylenediamine were placed in a 500mL three-necked flask and 126mL of 70% perchloric acid were slowly added dropwise with stirring over 120 minutes under ice-bath conditions. The initial reaction was vigorous with white smoke generation, so the dropping rate was controlled to be one drop per 5 seconds. The dropping speed can be increased appropriately as the reaction proceeds until the dropping is completed, and a transparent solution is obtained. Still under ice-water bath conditions, to the clear solution was added 224mL of anhydrous acetone and stirred vigorously, the solution quickly becoming cloudy and a very viscous mixture formed. Still under ice-water bath conditions for 2-3 hours for adequate reaction. And transferring the obtained product to a Buchner funnel for suction filtration and separation, and fully washing the product with acetone to obtain a pure white solid. Recrystallizing the self-color solid in hot methanol-water solution, and vacuum drying with silica gel desiccant to obtain 80g white crystal of L.2 HClO₄。

Reference documents:

1.Curtis, N. F. and Hay, R. W. , J. Chem. Soc. , Chem. Commun. , 1966, p. 534.

2.Gang Hu, Panpan Chen, Wei Wang, Lin Hu, Jimei Song, LingguangQiu, Juan Song, E1ectrochimica Acta, 2007, Vol. 52, pp. 7996-8002.

3. Lin Hu, Gang Hu, Han-Hong Xu, J. Ana1. Chem. , 2006, Vol. 61, NO. 10, pp. 1021-1025.

4. hugang, doctor's paper of Chinese university of science and technology, p25-27, fertilizer combination, 2005.

2) From L.2 HClO₄Preparation of [ NiL](ClO₄)₂：

Mix 11g Ni (AC)₂4H₂O and 21g of L.2 HClO₄Placing in a 500mL three-necked bottle, dissolving in 250mL methanol, heating and refluxing in a hot water bath for 3 hours, finally generating yellow precipitate, filtering, concentrating the filtrate in the hot water bath to the original volume l/2, standing overnight, and fully crystallizing to obtain yellow crystals. The yellow crystals were transferred to a Buchner funnel and washed with methanol, recrystallized from hot ethanol-water solution, and dried under vacuum to give 8g of [ NiL ]](ClO₄)₂Bright yellow crystals.

Reference documents:

1. N. F. Curtis, J. Chem. Soc. Dolton Tran. , 1972, Vol. 13, 1357.

2. hugang, doctor's paper of Chinese university of science and technology, p42-43, fertilizer combination, 2005.

2) From L.2 HClO₄Preparation of [ NiL](ClO₄)₂：

Mix 11g Ni (AC)₂4H₂O and 21g of L.2 HClO₄Placing in a 500mL three-necked bottle, dissolving in 250mL methanol, heating and refluxing in a hot water bath for 3 hours, finally generating yellow precipitate, filtering, concentrating the filtrate in the hot water bath to the original volume l/2, standing overnight, and fully crystallizing to obtain yellow crystals. The yellow crystals were transferred to a Buchner funnel and washed with methanol, recrystallized from hot ethanol-water solution, and dried under vacuum to give 8g of [ NiL ]](ClO₄)₂Bright yellow crystals.

Reference documents:

1. N. F. Curtis, J. Chem. Soc. Dolton Tran. , 1972, Vol. 13, 1357.

2. hugang, doctor's paper of Chinese university of science and technology, p42-43, fertilizer combination, 2005.

The present discrimination method is different from the prior art in that,application of the invention "H₂SO₄ -KIO₃-[NiL](ClO₄)₂-malonic acid-H₂O₂The chemical oscillation system is used as a distinguishing solution, and the alpha-naphthol and the beta-naphthol have different influences on the potential oscillation spectrum of the distinguishing solution, so that the distinguishing of the alpha-naphthol and the beta-naphthol is realized.

Alpha-naphthol and beta-naphthol, in a distinguishable concentration range of 2.5X 10 in a discriminating solution (chemically shaken system)^-6-1×10^-5mol/L。

The concentration ranges that can be distinguished by the solutions to be distinguished are the optimum concentration ranges determined experimentally. Within the concentration range, the influence difference of alpha-naphthol and beta-naphthol on the distinguishing solution is very obvious, and the distinguishing solution is easy to observe and analyze and realize distinguishing. In addition, the concentration ranges of the components in the discrimination solution (chemical oscillation system) are shown in table 1, and the optimum solution of the discrimination solution (chemical oscillation system) obtained through a plurality of experiments is shown in table 2:

table 1: concentration range of each component in chemical oscillation system

Sulfuric acid (mol/L)	Potassium iodate (mol/L)	[NiL](ClO4)2 (mol/L)	Malonic acid (mol/L)	Hydrogen peroxide (mol/L)
					0.0246468-0.025	0.0175-0.021	6.4875×10-4-8.65×10-4	0.125-0.165	1.35-1.52

Table 2: optimum concentration of each component in chemical oscillation system

Sulfuric acid (mol/L)	Potassium iodate (mol/L)	[NiL](ClO4)2(mol/L)	Malonic acid (mol/L)	Hydrogen peroxide (mol/L)
					0.025	0.01855	8.65×10-4	0.15	1.5

The specific experimental steps are as follows:

1. preparing a distinguishing solution according to the concentration range specified in table 1, inserting a prepared working electrode (platinum electrode) and a reference electrode (calomel electrode) into the solution, connecting the other end of the working electrode to a data collector (Go | LINK) through an Amplifier (Instrument Amplifier), connecting the other end of the working electrode to a computer, starting a loader lite program in the computer to set the collection time and the sampling speed, quickly clicking a start key to monitor the potential of the solution, and obtaining an acquired E-t curve (the curve of the potential value changing along with the time), namely a chemical potential oscillation map (at the moment, a sample to be detected is not added) to be used as a blank contrast. And (3) respectively and rapidly adding the solution of the sample to be distinguished to any one stable potential lowest point generated by oscillation in two groups of distinguishing solutions with the same component concentration as that in the blank control experiment, and realizing qualitative analysis of the sample to be distinguished according to different oscillation responses of the sample to be distinguished to a chemical oscillation system. The method comprises the following specific steps: if the chemical oscillation is inhibited after the solution to be distinguished is added, and the oscillation is recovered after a long inhibition time, the added sample to be distinguished is alpha-naphthol; if the chemical oscillation is inhibited after the solution to be distinguished is added, and the oscillation is recovered after a short inhibition time, the added sample to be distinguished is beta-naphthol.

The basic parameters of the chemical potential oscillation spectrum include:

oscillation amplitude: the potential difference from one lowest potential to the next highest potential during oscillation.

Oscillation period: the time required from one lowest (high) potential to the next lowest (high) potential during oscillation.

The highest potential: the highest potential point of the system appears when the system oscillates stably.

Lowest potential: the lowest point of potential of the system appears when the system oscillates stably.

Inhibition time (t)_in): the time from the inhibition of oscillation after the liquid to be tested is added to the resumption of oscillation.

Oscillation life: the oscillation is from the beginning to the end of the oscillation.

Drawings

FIG. 1 is a vibration pattern of a discrimination solution (chemical oscillation system) in example 1 without adding a sample to be discriminated.

FIG. 2 is a graph of example 1, with the addition of 2.5X 10^-6And (3) after mol/L alpha-naphthol is added, obtaining an oscillation response spectrum by a chemical oscillation system.

FIG. 3 is a graph of example 1, with 2.5X 10^-6After mol/L beta-naphthol, obtained by chemical oscillation systemAnd obtaining an oscillation response map.

FIG. 4 is a vibration pattern of the discrimination solution (chemical oscillation system) in example 2 without adding the sample to be discriminated.

FIG. 5 is a schematic representation of example 2, with the addition of 5X 10^-6And (3) after mol/L alpha-naphthol is added, obtaining an oscillation response spectrum by a chemical oscillation system.

FIG. 6 is a graph of example 2, with 5X 10 added^-6And (3) after mol/L of beta-naphthol, obtaining an oscillation response spectrum by a chemical oscillation system.

FIG. 7 is a vibration pattern of the discrimination solution (chemical oscillation system) in example 3 when the sample to be discriminated is not added.

FIG. 8 is a graph showing that in example 3, 1X 10 is added^-5And (3) after mol/L alpha-naphthol is added, obtaining an oscillation response spectrum by a chemical oscillation system.

FIG. 9 is a schematic representation of example 3, with the addition of 1X 10^-5And (3) after mol/L of beta-naphthol, obtaining an oscillation response spectrum by a chemical oscillation system.

Detailed Description

Example 1:

this example verifies the feasibility of the method for distinguishing alpha-naphthol from beta-naphthol according to the invention by the following steps:

(1) preparing solution

Firstly, 98% concentrated sulfuric acid and distilled water are used to prepare 0.025mol/L sulfuric acid as stock solution, then 0.025mol/L sulfuric acid solution is used to prepare 0.14mol/L potassium iodate solution and 0.0173mol/L [ NiL ] solution](ClO₄)₂The solution, 2mol/L malonic acid solution and 4mol/L hydrogen peroxide solution. Into a 50mL beaker were added 14.7mL of a 0.025mol/L sulfuric acid solution, 5.3mL of a 0.14mol/L potassium iodate solution, and 2.0mL of 0.0173mol/L [ NiL ] in that order](ClO₄)₂Solution, 3mL of 2mol/L malonic acid solution and 15.0mL of 4mol/L hydrogen peroxide solution to ensure "H₂SO₄ - KIO₃ - [NiL](ClO₄)₂ -malonic acid-H₂O₂The concentrations of the components in the chemical oscillation system are 0.025mol/L sulfuric acid, 0.01855mol/L potassium iodate and [ NiL](ClO₄)₂ 8.65×10^-4mol/L, 0.15mol/L of malonic acid and 1.5mol/L of hydrogen peroxide；

Simultaneously, ethanol is used as a solvent to prepare 0.002mol/L alpha-naphthol solution and beta-naphthol solution respectively.

(2) Oscillation atlas

The potentiometric oscillation pattern of the chemical oscillation system was recorded by a computer equipped with the program logger lite, FIG. 1 showing the results of the measurement at typical concentrations (0.025 mol/L sulfuric acid, 0.01855mol/L potassium iodate, [ NiL ]](ClO₄)₂8.65×10^-4mol/L, 0.15mol/L of malonic acid and 1.5mol/L of hydrogen peroxide), and the above distinguishing solution is not added with the oscillation spectrum of the sample to be tested to be used as a blank control. To two groups of discrimination solutions with the same component concentration as the above concentration, 50. mu.L of 0.002mol/L alpha-naphthol and beta-naphthol are respectively added, so that the concentration of the alpha-naphthol and the beta-naphthol in the discrimination solutions is 2.5 multiplied by 10^-6mol/L, the time of each addition is at the 6 th potential lowest point of the oscillation map, and the obtained oscillation response maps are respectively shown in FIG. 2 and FIG. 3.

(3) Distinguishing

The alpha-naphthol and the beta-naphthol serving as the isomer thereof have different space structures, so the influence on a chemical oscillation system is different. As can be seen from a comparison of FIG. 2 and FIG. 3, the addition of alpha-naphthol suppresses the chemical oscillation and resumes the oscillation after a longer suppression time; the addition of beta-naphthol suppresses the chemical oscillation and resumes oscillation after a short period of suppression. As can be seen from the above experiments, the discrimination between alpha-naphthol and beta-naphthol can be achieved by comparing the change in the oscillation spectrum.

Taking two 0.002mol/L solutions of samples to be distinguished (one is an alpha-naphthol solution, the other is a beta-naphthol solution, but the two are not distinguished) prepared in advance, marking one of the solutions as a sample 1, and marking the other as a sample 2;

preparing two groups of chemical oscillation solutions with the same component concentration as the above concentration, respectively collecting corresponding oscillation maps, and respectively adding 50 μ L of 0.002mol/L sample 1 and sample 2 at the 7 th potential lowest point to make their concentration in the discrimination solution 2.5 × 10^-6mol/L。

The analysis and comparison can show that: the addition of sample 1 suppressed the chemical oscillations and restored them after a longer period of inhibition (the oscillation pattern corresponds to figure 2 and does not correspond to figure 3), while the addition of sample 2 suppressed the chemical oscillations and restored them after a shorter period of inhibition (the oscillation pattern corresponds to figure 3 and does not correspond to figure 2). Therefore, the sample 1 is an alpha-naphthol solution, and the sample 2 is a beta-naphthol solution, so that the alpha-naphthol solution and the beta-naphthol solution are distinguished.

Example 2:

this example verifies the feasibility of the method for distinguishing alpha-naphthol from beta-naphthol according to the invention by the following steps:

(1) preparing solution

Firstly, 98% concentrated sulfuric acid is used to prepare 0.025mol/L sulfuric acid as stock solution, then 0.025mol/L sulfuric acid solution is used to prepare 0.14mol/L potassium iodate solution and 0.0173mol/L [ NiL ] respectively](ClO₄)₂The solution, 2mol/L malonic acid solution and 4mol/L hydrogen peroxide solution; to a 50mL beaker were added 15.0mL of a 0.025mol/L sulfuric acid solution, 5.3mL of a 0.14mol/L potassium iodate solution, and 2mL of 0.0173mol/L [ NiL ] in that order](ClO₄)₂Solution, 2.7mL of 2mol/L malonic acid solution, 15mL of 4mol/L hydrogen peroxide solution to ensure "H₂SO₄ - KIO₃ - [NiL](ClO₄)₂ -malonic acid-H₂O₂The concentrations of the components in the chemical oscillation system are 0.025mol/L sulfuric acid, 0.01855mol/L potassium iodate and [ NiL](ClO₄)₂ 8.65×10^-4mol/L, 0.135mol/L of malonic acid and 1.5mol/L of hydrogen peroxide;

simultaneously, ethanol is used as a solvent to prepare 0.002mol/L alpha-naphthol solution and beta-naphthol solution respectively.

(2) Oscillation atlas

The potential oscillation spectrum of the chemical oscillation system is recorded by a computer provided with a logger lite program, and the difference between the oscillation responses generated by alpha-naphthol and beta-naphthol is inspected. FIG. 4 is a graph of the oscillation spectrum of a discrimination solution without adding a test sample as a blank. Respectively adding 100 mul of 0.002mol/L alpha-naphthol solution and beta-naphthol solution into two groups of distinguishing solutions with the same component concentration as the concentration so as to enable the solutions to be in the state ofThe concentration in the solution was 5X 10^-6mol/L, the time of each addition is at the 6 th potential lowest point of the oscillation map, and the obtained oscillation response maps are respectively shown in FIG. 5 and FIG. 6.

(3) Distinguishing

The alpha-naphthol and the beta-naphthol serving as the isomer thereof have different space structures, so the influence on a chemical oscillation system is different. Comparing fig. 5 to fig. 6, it can be seen that the addition of α -naphthol suppresses the chemical oscillation and resumes the oscillation after a longer suppression time; the addition of beta-naphthol suppresses the chemical oscillation and resumes oscillation after a short period of suppression. As can be seen from the above experiments, the discrimination between alpha-naphthol and beta-naphthol can be achieved by comparing the change in the oscillation spectrum.

Taking two 0.002mol/L solutions of samples to be distinguished (one is an alpha-naphthol solution, the other is a beta-naphthol solution, but the two are not distinguished) prepared in advance, marking one of the solutions as a sample 1, and marking the other as a sample 2;

preparing two groups of chemical oscillation solutions with the same component concentration as the component concentration, respectively collecting corresponding oscillation maps, and respectively adding 100 mu L of 0.002mol/L sample 1 and sample 2 at the 6 th potential lowest point to ensure that the concentrations of the two groups of chemical oscillation solutions in the solution are 5 multiplied by 10^-6mol/L。

The analysis and comparison can show that: the addition of sample 1 suppressed the chemical oscillations and restored them after a longer period of inhibition (the oscillation pattern corresponds to figure 5 and does not correspond to figure 6), while the addition of sample 2 suppressed the chemical oscillations and restored them after a shorter period of inhibition (the oscillation pattern corresponds to figure 6 and does not correspond to figure 5). Therefore, the sample 1 is an alpha-naphthol solution, and the sample 2 is a beta-naphthol solution, so that the alpha-naphthol solution and the beta-naphthol solution are distinguished.

Example 3:

this example verifies the feasibility of the method for distinguishing alpha-naphthol from beta-naphthol according to the following steps:

(1) preparing solution

Firstly, 98% concentrated sulfuric acid and distilled water are used0.025mol/L sulfuric acid is prepared as stock solution, and then 0.14mol/L potassium iodate solution and 0.0173mol/L [ NiL ] are prepared respectively by using 0.025mol/L sulfuric acid solution](ClO₄)₂The solution, 2mol/L malonic acid solution and 4mol/L hydrogen peroxide solution. To a 50mL beaker were added 15mL of a 0.025mol/L sulfuric acid solution, 5mL of a 0.14mol/L potassium iodate solution, and 1.8mL of 0.0173mol/L [ NiL ] in this order](ClO₄)₂Solution, 3.0mL of 2mol/L malonic acid solution and 15.2mL of 4mol/L hydrogen peroxide solution to ensure "H₂SO₄ - KIO₃ - [NiL](ClO₄)₂ -malonic acid-H₂O₂The concentrations of each component in the chemical oscillation system are 0.025mol/L sulfuric acid, 0.0175mol/L potassium iodate and [ NiL](ClO₄)₂ 7.785×10^-4mol/L, 0.15mol/L of malonic acid and 1.52mol/L of hydrogen peroxide;

simultaneously, ethanol is used as a solvent to prepare 0.002mol/L alpha-naphthol solution and beta-naphthol solution respectively.

(2) Oscillation atlas

The potential oscillation spectrum of the chemical oscillation system is recorded by a computer equipped with a logger lite program, and fig. 7 is an oscillation spectrum in which the above-mentioned discrimination solution is not added to the sample to be measured, for blank control. To two groups of discrimination solutions with the same component concentration as the concentration, 200 mu L of 0.002mol/L alpha-naphthol solution and 200 mu L of beta-naphthol solution are respectively added, so that the concentration of the alpha-naphthol solution and the concentration of the beta-naphthol solution in the discrimination solutions are both 1 multiplied by 10^-5mol/L, the time of each addition is at the 6 th potential lowest point of the oscillation map, and the obtained oscillation response maps are respectively shown in figures 8 and 9.

(3) Distinguishing

The alpha-naphthol and the beta-naphthol serving as the isomer thereof have different space structures, so the influence on a chemical oscillation system is different. Comparing fig. 8 and fig. 9, it can be seen that the addition of α -naphthol suppresses the chemical oscillation and resumes the oscillation after a longer suppression time; the addition of beta-naphthol suppresses the chemical oscillation and resumes oscillation after a short period of suppression. As can be seen from the above experiments, the discrimination between alpha-naphthol and beta-naphthol can be achieved by comparing the change in the oscillation spectrum.

Taking two 0.002mol/L solutions of samples to be distinguished (one is an alpha-naphthol solution, the other is a beta-naphthol solution, but the two are not distinguished) prepared in advance, marking one of the solutions as a sample 1, and marking the other as a sample 2;

preparing two groups of chemical oscillation solutions with the same component concentration as the concentration, respectively collecting corresponding oscillation maps, and respectively adding 200 mul of 0.002mol/L sample 1 and sample 2 at the 6 th potential lowest point to ensure that the concentrations of the two groups of chemical oscillation solutions in the distinguishing solutions are 1 x 10^-5mol/L。

The analysis and comparison can show that: the addition of sample 1 suppressed the chemical oscillations and restored them after a longer period of inhibition (the oscillation pattern corresponds to figure 8, not to figure 9), while the addition of sample 2 suppressed the chemical oscillations and restored them after a shorter period of inhibition (the oscillation pattern corresponds to figure 9, not to figure 8). Therefore, the sample 1 is an alpha-naphthol solution, and the sample 2 is a beta-naphthol solution, so that the alpha-naphthol solution and the beta-naphthol solution are distinguished.

As can be seen from the above examples, solutions of smaller or larger concentrations of alpha-naphthol and solutions of beta-naphthol can also be distinguished by the method of the invention.