CN111638303A

CN111638303A - Distinguish metal ion Al3+And Zn2+Method (2)

Info

Publication number: CN111638303A
Application number: CN202010514151.4A
Authority: CN
Inventors: 胡刚; 周颖; 张兰兰
Original assignee: Anhui University
Current assignee: Anhui University
Priority date: 2020-06-08
Filing date: 2020-06-08
Publication date: 2020-09-08
Anticipated expiration: 2040-06-08
Also published as: CN111638303B

Abstract

Distinguish metal ion Al³⁺And Zn²⁺The method of (2), characterized by: by using "HCHO-NaHSO₃‑Na₂SO₃"pH clock reaction System as a differentiating solution according to Al³⁺And Zn²⁺Has different spectrum influence on the change of the pH value of the system along with the time, thereby realizing Al³⁺And Zn²⁺The differentiation of (1). The atlas provided by the distinguishing method has intuition, and can conveniently and quickly distinguish the metal ion Al³⁺And Zn²⁺And the equipment is simple, the accuracy is high, and the operation and the observation are easy.

Description

Distinguish metal ion Al3+And Zn2+Method (2)

Technical Field

The invention relates to a distinguishing method, in particular to a pH clock reaction system for metal ions Al³⁺And Zn² ⁺Belonging to the field of qualitative analytical chemistry.

Background

Al³⁺And Zn²⁺Belonging to the same metal cation. The aluminum ion is an ion formed by losing 3 electrons from an aluminum atom and is marked by Al³⁺. Aluminum is widely used as a common metal. Have been identified as food contaminants and controlled for reasons that can lead to loss of memory in humans. The zinc ion is obtained by losing two electrons of the outermost layer of the zinc atom, shows positive valence of 2, and is written as Zn²⁺Zinc ions are involved in the activities of many enzymes associated with human health and skin health, and are critical to the normal development of a variety of cells and natural and acquired immune functions. The zinc ions can competitively replace harmful metal ions and reduce the formation of free radicals in vivo. Due to zinc ion inThe life process plays many important roles, and the analysis and detection of zinc ions in cells become a research hotspot in recent years.

Detection of Al has been reported so far³⁺And Zn²⁺The method mainly comprises an ultraviolet-visible photometry, a fluorescent probe technology, an atomic absorption spectrum, an atomic emission spectrum, a plasma mass spectrum and the like. However, a more intuitive identification method for distinguishing the two is not reported, so that it is necessary to find a qualitative analysis method with good distinguishing effect, simple, convenient and quick operation and easy judgment of results.

Disclosure of Invention

The invention aims to be Al³⁺And Zn²⁺Provides a novel, convenient and fast distinguishing method, which is different from any known distinguishing method for Al³⁺And Zn²⁺The method of (1). The inventor applies a pH clock reaction system to Al³⁺And Zn²⁺The distinguishing method is based on the pH clock system to Al³⁺And Zn²⁺A pH clock system developed in response to the acute response. Specifically, the same concentration of sample solution (Al) to be distinguished³⁺And Zn²⁺) Respectively adding the samples into the two groups of pH clock systems, and realizing qualitative analysis of the samples to be distinguished according to different influences of the samples to be distinguished on the pH value of a clock reaction system: if the pH clock system has a large pH value drop and a final stable pH value is low after the sample to be distinguished is added, the added sample to be distinguished is Al³⁺(ii) a If the pH clock system has a small pH value reduction and a final stable pH value is high after the sample solution to be distinguished is added, the added sample to be distinguished is Zn²⁺. 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 is metal ion Al³⁺And Zn²⁺A discrimination method is provided, characterized in that:

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

by using "HCHO-NaHSO₃- Na₂SO₃The pH clock system is used as a distinguishing solution, a graph of the change of the pH value of the clock system along with time is recorded, when the pH value enters a stable pH value stage after suddenly rising, the solutions of samples to be distinguished are respectively added into the two groups of pH clock systems, and the samples to be distinguished are distinguished according to different influences of the samples to be distinguished on the pH value of a clock reaction system;

the samples to be distinguished respectively contain Al³⁺And Zn²⁺The sample of (1).

Adding the same concentration of sample solution to be distinguished (one of them is Al-containing) into two groups of distinguishing solutions (pH clock system)³⁺Sample, another one containing Zn²⁺Sample, but the two are not distinguished), if the pH clock system has a large pH value drop after the sample solution to be distinguished is added, and the final stable pH value is lower, the added sample to be distinguished is Al-containing³⁺A sample; if the pH clock system has a small pH value reduction and a final stable pH value is high after the sample solution to be distinguished is added, the added sample to be distinguished is Zn-containing²⁺And (3) sampling.

The pH value of the system is suddenly increased to enter a stable pH value stage, which means any stage between 120s and 400 s.

The difference between the present differentiation method and the prior art is that the present invention uses "HCHO-NaHSO₃- Na₂SO₃"pH clock System as a discriminating solution, utilizing Al³⁺And Zn²⁺The change patterns of the pH value of the solution with time are influenced differently, so that the effect on Al is realized³⁺And Zn²⁺The differentiation of (1).

Al³⁺And Zn²⁺The range of the concentration to be discriminated in the discrimination solution (pH clock system) was 1.0 × 10^-3-2.5×10^-3mol/L。

The concentration ranges that can be distinguished by the solutions to be distinguished are the optimum concentration ranges determined experimentally. In this concentration range, Al³⁺And Zn²⁺The difference of the influence on the distinguishing solution is very obvious, and the distinguishing solution is easy to observe and analyze and realize distinguishing. In addition, solutions are distinguished (pH clock system)) The optimum concentration of each component in (A) is shown in Table 1:

table 1: concentration of Components in a pH clock System

[0016] HCHO(mol/ L)	[0017] NaHSO₃(mol/L)	[0018] Na₂SO₃ (mol/L)
			[0019] 0.05	[0020] 0.05	[0021] 0.005

The specific experimental steps are as follows:

1. preparing and distinguishing solution according to the concentration specified in table 1, inserting a prepared working electrode (pH electrode) into the solution, connecting the other end of the working electrode to a computer through a potential/temperature/pH comprehensive tester, starting a chemical signal acquisition and analysis program in the computer to set acquisition time and sampling speed, and then quickly clicking a start key to monitor the pH of the solution to obtain an acquired pH-t curve (a curve of the change of a pH value along with time), namely a map of a pH clock system (at the moment, a sample to be detected is not added) to be used as blank contrast. And (3) respectively and rapidly adding the solutions of the samples to be distinguished into two groups of distinguishing solutions with the same component concentration as those in the blank control experiment when the pH value suddenly rises and enters a stable pH value stage, and qualitatively distinguishing the samples to be distinguished according to different influences of the solutions of the samples to be distinguished on the pH of a pH clock reaction system. Namely: after the solution of the sample to be distinguished is added into the pH clock system, the qualitative analysis of the sample to be distinguished is realized according to the difference between the pH value of the system and the final stable pH value of the sample to be distinguished.

Basic parameters of the pH clock system map include:

sudden increase in pH (jump): the sharp rise in pH jumps from a low pH to a stable high pH.

Drawings

FIG. 1 is a graph of the change in pH over time of a discrimination solution (pH clock system) in example 1 without the addition of a sample to be discriminated.

FIG. 2 shows that in example 1, 1.0 × 10 was added separately^-3mol/LAl³⁺And Zn²⁺And then, obtaining a response contrast map by using a pH clock system.

FIG. 3 shows that in example 2, 1.5 × 10 was added separately^-3mol/L Al³⁺And Zn²⁺And then, obtaining a response contrast map by using a pH clock system.

FIG. 4 shows that in example 3, 2.5 × 10 was added separately^-3mol/L Al³⁺And Zn²⁺And then, obtaining a response contrast map by using a pH clock system.

Detailed Description

Example 1:

this example demonstrates the Al of the invention as follows³⁺And Zn²⁺Feasibility of the differentiation method of (1):

(1) preparing solution

Firstly, distilled water is used for preparing 0.2mol/L HCHO solution and 0.1mol/L NaHSO₃And 0.01mol/L of Na₂SO₃The mixed solution of (1). To a 50mL beaker were added 10mL of the distilled aqueous solution, 20mL of NaHSO in that order₃- Na₂SO₃Mixed solution, 10mL of 0.2mol/L HCHO solution, to ensure "HCHO-NaHSO₃- Na₂SO₃"concentration of each component in the non-linear chemical clock system is HCHO 0.05mol/L, NaHSO₃0.05mol/L、Na₂SO₃0.005mol/L；

At the same time, distilled water is used as solvent to respectively prepare 1.0mol/L Al-containing solution³⁺And containing Zn²⁺Solution (Al (NO)₃)₃And Zn (NO)₃)₂A solution).

(2) System map

The pH-time-dependent profile of the pH clock system was recorded by a computer equipped with a chemical signal acquisition analysis program, FIG. 1 being the graph at typical concentrations (HCHO 0.05mol/L, NaHSO)₃0.05mol/L、Na₂SO₃0.005 mol/L), and a blank control is performed by adding no atlas of the pH value of the sample to be detected changing along with time into the distinguishing solution. To two groups of discrimination solutions with the same concentration of each component as above, 40. mu.L of 1.0mol/L Al was added³⁺And Zn²⁺So that the concentrations thereof in the discrimination solutions were all 1.0 × 10^-3mol/L, the time of each addition was when a steady pH phase was entered after a sudden pH rise (t =150 s), and a response contrast graph was obtained as shown in fig. 2.

(3) Differentiation of Al³⁺And Zn²⁺

Al³⁺And Zn²⁺Are different metal ions, and have different effects on a pH clock system. As can be seen from FIG. 2, Al³⁺The addition of (3) enables the pH clock system to have a large pH value reduction and a final stable pH value to be lower; zn²⁺The addition of (2) causes the pH clock system to have a small degree of pH value reduction and a final stable pH value higher. As can be seen from the above experiments, by comparing the change of the map, Al can be achieved³⁺And Zn²⁺The differentiation of (1).

Two 1.0mol/L solutions of samples to be distinguished (one of which is Al (NO) prepared in advance are taken₃)₃I.e. containing Al³ ⁺Sample solution, another being Zn (NO)₃)₂I.e. containing Zn²⁺Sample solution, but not both), one is labeled sample 1 and the other is labeled sample 2;

preparing two groups of pH clock solutions with the same component concentration as the above concentration, respectively collecting corresponding maps, and respectively adding 40 mu L of sample 1 and sample 2 of 1.0mol/L when the system enters a stable pH value stage (t =150 s) after the pH value of the system is suddenly increased, so that the concentrations of the samples in the solution are 1.0 × 10^-3mol/L。

The analysis and comparison can show that: the addition of sample 1 resulted in a large pH drop in the pH clock system and a low final stable pH (the profile corresponds to curve a and does not correspond to curve b in fig. 2), while sample 2 resulted in a small pH drop in the pH clock system and a high final stable pH (the profile corresponds to curve a and does not correspond to curve b in fig. 2)The spectrum corresponds to curve b and not curve a in fig. 2). Thus, sample 1 is Al-containing³⁺Sample solution, sample 2 is Zn-containing²⁺Sample solution, thereby realizing the effect on Al³⁺Solution and Zn²⁺And (4) distinguishing solutions.

Example 2:

(1) preparing solution

(2) System map

The pH-time-dependent profile of the pH clock system was recorded by a computer equipped with a chemical signal acquisition analysis program, FIG. 1 being the graph at typical concentrations (HCHO 0.05mol/L, NaHSO)₃0.05mol/L、Na₂SO₃0.0005 mol/L) and a spectrum of the pH value of the sample to be detected changing along with time is not added into the distinguishing solution to be used as a blank control. To two groups of discrimination solutions with the same concentration of each component as above, 60. mu.L of 1.0mol/L Al was added³⁺And Zn²⁺So that the concentrations thereof in the discrimination solutions were all 1.5 × 10^-3mol/L, the time of each addition was when a steady pH phase was entered after a sudden pH rise (t =150 s), and a response contrast graph was obtained as shown in fig. 3.

(3) Differentiation of Al³⁺And Zn²⁺

Al³⁺And Zn²⁺Are different metal ions, and have different effects on a pH clock system. As can be seen from FIG. 3, Al³⁺The addition of (3) enables the pH clock system to have a large pH value reduction and a final stable pH value to be lower; zn²⁺The addition of (2) causes the pH clock system to have a small degree of pH value reduction and a final stable pH value higher. As can be seen from the above experiments, by comparing the change of the map, Al can be achieved³⁺And Zn²⁺The differentiation of (1).

Two 1.0mol/L solutions of samples to be distinguished (one of which is Al (NO) prepared in advance are taken₃)₃I.e. containing Al³⁺Sample solution, another being Zn (NO)₃)₂I.e. containing Zn²⁺Sample solution, but not both), one is labeled sample 1 and the other is labeled sample 2;

preparing two groups of pH clock solutions with the same component concentration as the above concentration, respectively collecting corresponding maps, and respectively adding 60 mu L of sample 1.0mol/L and sample 2 when the system enters a stable pH value stage (t =150 s) after the pH value of the system is suddenly increased, so that the concentrations of the two groups of samples in the solution are 1.5 × 10^-3mol/L。

The analysis and comparison can show that: the addition of sample 1 resulted in a large pH drop in the pH clock system and a low final stable pH (the profile corresponds to curve a and does not correspond to curve b in fig. 3), while sample 2 resulted in a small pH drop in the pH clock system and a high final stable pH (the profile corresponds to curve b and does not correspond to curve a in fig. 3). Thus, sample 1 is Al-containing³⁺Sample solution, sample 2 is Zn-containing²⁺Sample solution, thereby realizing the effect on Al³⁺Solution and Zn²⁺And (4) distinguishing solutions.

Example 3:

(1) preparing solution

Firstly, preparing 0.2mol/L HCHO solution by using distilled waterLiquid, 0.1mol/L NaHSO₃And 0.01mol/L of Na₂SO₃The mixed solution of (1). To a 50mL beaker were added 10mL of the distilled aqueous solution, 20mL of NaHSO in that order₃- Na₂SO₃Mixed solution, 10mL of 0.2mol/L HCHO solution, to ensure "HCHO-NaHSO₃- Na₂SO₃"concentration of each component in the non-linear chemical clock system is HCHO 0.05mol/L, NaHSO₃0.05mol/L、Na₂SO₃0.005mol/L；

(2) System map

The pH-time-dependent profile of the pH clock system was recorded by a computer equipped with a chemical signal acquisition analysis program, FIG. 1 being the graph at typical concentrations (HCHO 0.05mol/L, NaHSO)₃0.05mol/L、Na₂SO₃0.005 mol/L), and a blank control is performed by adding no atlas of the pH value of the sample to be detected changing along with time into the distinguishing solution. To two groups of discrimination solutions with the same concentration of each component as above, 100. mu.L of 1.0mol/L Al was added³⁺And Zn²⁺So that the concentrations thereof in the discrimination solutions were all 2.5 × 10^-3mol/L, the time of each addition was when a steady pH phase was entered after a sudden pH rise (t =150 s), and a response profile was obtained as shown in fig. 4.

(3) Differentiation of Al³⁺And Zn²⁺

Al³⁺And Zn²⁺Are different metal ions, and have different effects on a pH clock system. As can be seen from FIG. 4, Al³⁺The addition of (3) enables the pH clock system to have a large pH value reduction and a final stable pH value to be lower; zn²⁺The addition of (2) causes the pH clock system to have a small degree of pH value reduction and a final stable pH value higher. As can be seen from the above experiments, by comparing the change of the map, Al can be achieved³⁺And Zn²⁺The differentiation of (1).

Taking two prepared in advance1.0mol/L of a solution of samples to be distinguished (one of them being Al (NO)₃)₃I.e. containing Al³ ⁺Sample solution, another being Zn (NO)₃)₂I.e. containing Zn²⁺Sample solution, but not both), one is labeled sample 1 and the other is labeled sample 2;

preparing two groups of pH clock solutions with the same component concentration as the above concentration, respectively collecting corresponding maps, and respectively adding 100 mu L of sample 1 and sample 2 of 1.0mol/L when the system enters a stable pH value stage (t =150 s) after the pH value of the system is suddenly increased, so that the concentrations of the two groups of samples in the solution are 2.5 × 10^-3mol/L。

The analysis and comparison can show that: the addition of sample 1 resulted in a large pH drop in the pH clock system and a low final stable pH (the profile corresponds to curve a and does not correspond to curve b in fig. 4), while sample 2 resulted in a small pH drop in the pH clock system and a high final stable pH (the profile corresponds to curve b and does not correspond to curve a in fig. 4). Thus, sample 1 is Al-containing³⁺Sample solution, sample 2 is Zn-containing²⁺Sample solution, thereby realizing the effect on Al³⁺Solution and Zn²⁺And (4) distinguishing solutions.

As can be seen from the above examples, smaller or larger concentrations of Al³⁺And Zn²⁺Can also be distinguished by the method of the invention.

Claims

1. Distinguish metal ion Al³⁺And Zn²⁺The method of (2), characterized by:

identifying the molar concentrations of the components in the solution as follows: HCHO 0.05mol/L, NaHSO₃0.05mol/L、Na₂SO₃0.005mol/L；

2. The discrimination method according to claim 1, characterized in that:

respectively adding the sample solutions to be distinguished with the same concentration into the two groups of pH clock systems, and if the pH clock systems have a large pH value reduction and a final stable pH value is low after the sample solutions to be distinguished are added, determining that the added samples to be distinguished contain Al³⁺A sample; if the pH clock system has a small pH value reduction and a final stable pH value is high after the sample solution to be distinguished is added, the added sample to be distinguished is Zn-containing²⁺And (3) sampling.

3. The distinguishing method according to claim 1 or 2, characterized in that: the pH value of the system is suddenly increased to enter a stable pH value stage, which means any stage between 120s and 400 s.

4. The discrimination method according to claim 1 or 2, wherein the discriminated concentration range of the sample to be discriminated in the discrimination solution is 1.0 × 10^-3-2.5×10^-3mol/L。