CN106187941A - One can identify inorganic mercury and organomercurial sensitive high selectivity colorimetric probe simultaneously - Google Patents

Abstract

The invention relates to a sensitive and highly selective colorimetric probe capable of simultaneously identifying inorganic mercury and organic mercury. Specifically, the probe of the present invention is a class of benzothiazole compounds with vinyl ether as the recognition receptor, which can be used for the detection of mercury ions. This type of probe can achieve at least one of the following technical effects: highly selective identification of inorganic mercury ions/organic mercury ions; instant detection of mercury ions; naked-eye detection; stable properties and long-term storage and use; It is beneficial to detect mercury ions in actual samples; and has strong anti-interference ability.

Description

A sensitive and highly selective colorimetric probe capable of simultaneously recognizing inorganic and organic mercury

technical field

The invention relates to a benzothiazole compound with vinyl ether as a recognition receptor as a colorimetric probe for simultaneous analysis of inorganic mercury and organic mercury, which can be used in sensitive and high-selective recognition under specific conditions, or it can be used to determine samples Concentrations of inorganic and/or organic mercury in water.

Background technique

Mercury is an element with strong toxicity, easy to accumulate, and difficult to degrade. Even at very low concentrations, mercury can cause permanent damage to the human nervous system and endocrine system. In particular, it should be pointed out that inorganic mercury may be transformed into more toxic organic mercury under the action of aquatic biological systems, passed through the food chain and finally enriched in the human body, threatening human life and health at all times. Therefore, the change and development of mercury detection methods is urgent.

At present, the common detection methods of mercury are mainly X-ray fluorescence spectrometry, atomic absorption/emission spectrometry, inductively coupled plasma-mass spectrometry, nuclear magnetic resonance, electrochemical methods (such as anodic stripping voltammetry, redox potential method, etc.) . However, these analysis methods require expensive and special experimental instruments in practical application, and also require experimental operators to have a high level of professional research. Therefore, efficient, simple, and low-cost mercury detection methods have become an important research topic at this stage.

Among various detection methods of ions/molecules, the colorimetric probe detection method is very attractive due to its simple operation and no need for any expensive equipment. However, the currently reported colorimetric probes still have some problems, including poor water solubility, poor selectivity, recognition of only inorganic mercury, and complex synthesis. In conclusion, it is an urgent problem for those skilled in the art to develop a colorimetric probe with high selectivity, simple synthesis, convenient detection method and the ability to recognize both inorganic mercury and organic mercury.

Contents of the invention

There is an urgent need in the field for a simple, sensitive and highly selective colorimetric probe capable of simultaneously recognizing inorganic mercury and organic mercury, so as to effectively detect mercury species. For this reason, the present invention has synthesized a class of novel colorimetric probes, which are simple in synthesis, high in stability, and high in selectivity. It is particularly pointed out that this probe can not only detect inorganic mercury, but also detect more toxic Organic Mercury, a strong step forward in the detection of mercury species.

Specifically, the present invention provides a colorimetric probe for simultaneous analysis of inorganic mercury and organic mercury, which is a benzothiazole compound with the following structure:

Preferably, the colorimetric probe of the present invention is:

In the preparation method of the mercury ion colorimetric probe of the present invention, the reaction temperature is 20°C-80°C; the reaction time is 1-24h; the molar ratio of benzothiazole compounds to p-benzaldehyde vinyl ether is about 1: 1 to 1:2, preferably 1:1.2 or 1:1.3.

The present invention also provides a detection preparation or kit for detecting the concentration of mercury ions in a sample (such as a river water sample), which comprises the probe of the present invention. Preferably, the detection preparation or kit of the present invention further includes instructions for use of the product. Still preferably, the kit of the present invention further comprises a buffer for determining the concentration of mercury ions in the sample.

The present invention also provides a method for detecting mercury ion concentration in a sample (such as a river water sample), which includes the step of contacting the probe of the present invention with the sample to be tested.

The present invention also provides the use of the probe of the present invention in the preparation of preparations for detecting the concentration of mercury ions in samples (such as river water samples).

The present invention also provides the use of the probe of the present invention in preparing a kit for detecting the concentration of mercury ions in a sample (such as a river water sample).

The colorimetric probe for simultaneous analysis of inorganic mercury and organic mercury of the present invention can respectively react with inorganic mercury and organic mercury to produce changes in absorption spectra, thereby realizing quantitative detection of mercury ions.

Specifically, the colorimetric probe for simultaneous analysis of inorganic mercury and organic mercury of the present invention interacts with cadmium ions, lead ions, cobalt ions and other metal ions respectively, which cannot cause obvious changes in the absorption spectrum, thereby realizing the detection of mercury ions. Selective identification, in turn, can optionally be used to exclude the presence of these and other ions from interfering with the quantitative determination of mercury ions.

Optionally, the colorimetric probe for simultaneous analysis of inorganic mercury and organic mercury of the present invention has good stability and can be preserved and used for a long time.

Further, the colorimetric probe for simultaneous analysis of inorganic mercury and organic mercury of the present invention has high sensitivity and high selectivity, and is simple to synthesize, simple and convenient to detect and operate, and is conducive to commercial promotion and application.

Description of drawings

Figure 1 shows the influence of different analytes (25 μM) on the absorption spectrum of the probe (10 μM) and the influence of different analytes (25 μM) on the quantitative analysis of Hg ²⁺ (25 μM) by the absorption spectrum of the probe (10 μM). (Wherein, the black column represents the change in the absorbance of various metal ions added with 25 μM in the pure water system with a probe concentration of 10 μM, and the red column represents the addition of 25 μM mercury ions in the probe system, respectively adding 25 μM Cd ²⁺ , Fe ³⁺ , Pb ²⁺ , Cu ²⁺ , Co ²⁺ , Ni ²⁺ , Fe ²⁺ , Zn ²⁺ , Sn ²⁺ , Al ³⁺ , Ca ²⁺ , Na ⁺ , K ⁺ , The change of the absorbance of Mg ²⁺ . The test temperature is carried out at 25°C.)

Figure 2 shows the influence of different concentrations of Hg ²⁺ (0-15 μM) on the absorption spectrum of the probe (10 μM) and the quantitative linear relationship.

Figure 3(a) is the naked-eye detection of mercury ions by probes, where the probe concentration is 10 μM, the mercury ion concentrations are 0, 0.5, 1, 2, and 3 μM, the test system is pure water, and the test temperature is 25°C.

Figure 3(b) is the naked-eye detection of methylmercury by the probe, where the concentrations of methylmercury are 0, 20, 40, 80, and 200 μM, the test system is pure water, and the test temperature is 25°C.

detailed description:

The invention provides the synthesis route, method and spectral performance of the colorimetric probe for simultaneous analysis of inorganic mercury and organic mercury with high sensitivity and high selectivity.

The colorimetric probe capable of simultaneously analyzing inorganic mercury and organic mercury of the present invention is a class of benzothiazole compounds, which have the following general structural formula

In the above formula: R ₁ , R ₂ , R ₃ and R ₄ are hydrogen atoms, straight chain or branched chain alkyl, straight chain or branched chain alkoxy, sulfonic acid group, ester group, carboxyl group; R ₁ , R ₂ , _R3 and _R4 can be the same or different.

The synthetic route and method of this class fluorescent probe are as follows:

Specifically, the colorimetric probe of the present invention can be prepared by the following method, a certain molar ratio (such as 1:1-1:2) of benzothiazole compounds (such as benzothiazole-2-acetonitrile) and p-benzaldehyde Vinyl ether was dissolved in ethanol, and 3-4 drops of triethylamine were added to adjust the pH value, then stirred at a suitable temperature (25°C) for a period of time (eg, 10h), and then rotary evaporated to obtain a crude product. Using petroleum ether: dichloromethane = 5:1 (V/V) system for column chromatography to obtain 316 mg of pure product with a yield of 92%.

The present invention also provides the use of benzothiazole compounds (such as benzothiazole-2-acetonitrile) in the preparation of colorimetric probes for detecting mercury ions.

The remarkable feature of the sensitive and highly selective colorimetric probe of the present invention is that it can identify inorganic mercury and organic mercury sensitively and selectively, and can accurately identify mercury in the presence of other high-concentration cadmium ions, lead ions, cobalt ions and other ions. Ions are quantified and can be analyzed with naked eyes.

The invention will be illustrated in more detail below by means of the following examples. The following examples are illustrative only, and it should be understood that the present invention is not limited by the following examples.

Example 1

(Scheme 1) Dissolve 200mg (1.35mmol) p-benzaldehyde vinyl ether, 196mg (1.13mmol) benzothiazole-2-acetonitrile and 3 drops of triethylamine in 20mL ethanol, then stir at 25°C for 10h, then The crude product was obtained by rotary evaporation, and finally separated by column chromatography using petroleum ether:dichloromethane=5:1 (V/V) system to obtain 316 mg of pure product with a yield of 92%.

(Scheme 2) Dissolve 217mg (1.47mmol) p-benzaldehyde vinyl ether, 196mg (1.13mmol) benzothiazole-2-acetonitrile and 3 drops of triethylamine in 20mL ethanol, then stir at 25°C for 10h, then The crude product was obtained by rotary evaporation, and finally separated by column chromatography using petroleum ether:dichloromethane=5:1 (V/V) system to obtain 314 mg of pure product with a yield of 92%.

(Scheme 3) Dissolve 167mg (1.13mmol) p-benzaldehyde vinyl ether, 196mg (1.13mmol) benzothiazole-2-acetonitrile and 3 drops of triethylamine in 20mL ethanol, then stir at 25°C for 10h, then The crude product was obtained by rotary evaporation, and finally separated by column chromatography using petroleum ether:dichloromethane=5:1 (V/V) system to obtain 309 mg of pure product with a yield of 90%.

(Scheme 4) Dissolve 251mg (1.70mmol) p-benzaldehyde vinyl ether, 196mg (1.13mmol) benzothiazole-2-acetonitrile and 3 drops of triethylamine in 20mL ethanol, then stir at 25°C for 15h, then The crude product was obtained by rotary evaporation, and finally separated by column chromatography using petroleum ether:dichloromethane=5:1 (V/V) system to obtain 307 mg of pure product with a yield of 90%.

(Scheme 5) Dissolve 334mg (2.26mmol) p-benzaldehyde vinyl ether, 196mg (1.13mmol) benzothiazole-2-acetonitrile and 3 drops of triethylamine in 20mL ethanol, then stir at room temperature for 15h, and then rotary evaporate to obtain The crude product was finally separated by column chromatography using a petroleum ether:dichloromethane=5:1 (V/V) system to obtain 314 mg of a pure product with a yield of 91%.

Example 2

The influence of different analytes (25μM) on the absorption spectrum of the probe (10μM) and the influence of different analytes (25μM) on the quantitative analysis of Hg ²⁺ (25μM) by the absorption spectrum of the probe (10μM).

Among them, the black column represents the change in the absorbance of various metal ions added at 25 μM to the pure water system with a probe concentration of 10 μM, and the red column represents the addition of 25 μM of Cd to the probe system with 25 μM of mercury ions. ²⁺ , Fe ³⁺ , Pb ²⁺ , Cu ²⁺ , Co ²⁺ , Ni ²⁺ , Fe ²⁺ , Zn ²⁺ , Sn ²⁺ , Al ³⁺ , Ca ²⁺ , Na ⁺ , K ⁺ , Mg ²⁺ changes in absorbance. The test temperature was carried out at room temperature of 25°C, and sodium hydroxide was added to the test system to adjust the pH of the solution system to 8. The results obtained are shown in Figure 1.

It can be seen from Figure 1 that the probe has high selectivity to mercury ions and can specifically react with mercury ions. Before and after the reaction, the absorbance changes significantly, while the absorption spectra of other ions and the probe do not change. Significant changes occurred. Moreover, other ions will not significantly interfere with the qualitative and quantitative detection of mercury ions by the probe.

Example 3

Effects of different concentrations of Hg ²⁺ (0-15μM) on the absorption spectrum of the probe (10μM). The above determination was carried out in the aqueous solution system after adding sodium hydroxide to adjust the pH to 8, and the probe used was the probe prepared in Example 1, and the results are shown in FIG. 2 .

It can be seen from Figure 2 that with the increase of Hg ²⁺ concentration in the probe solution, the absorbance value gradually increases, and within the range of 0-15 μM Hg ²⁺ concentration, the Hg ²⁺ concentration and absorbance show a linear relationship. Therefore, the probe of the present invention can more accurately determine the content of mercury ions in the sample to be tested.

Example 4

Quantitative naked-eye detection of mercury ions and methylmercury by probes. Prepare the probe at a concentration of 10 μM, add it to five small jars, add 0, 0.5, 1, 2, and 3 μM mercury ions into the jars with a pipette gun, and observe the color change with the naked eye. Following the same method, CH ₃ Hg ⁺ at concentrations of 0, 20, 40, 80, and 200 μM was added to five jars with a probe concentration of 10 μM, and the color changes were observed with the naked eye. The results obtained are shown in Figure 3.

From Figure 3(a) and (b), it can be seen that the solution gradually changes from colorless to yellow at the beginning, and the greater the concentration of mercury ions, the more obvious the color change of the solution. Therefore, we can detect low-concentration mercury ions and methylmercury in water with naked eyes, which is the outstanding advantage of our probe, and this advantage provides a convenient and feasible method for the detection of mercury ions and methylmercury in the water environment .

Although the present invention has been described with the above embodiments, it should be understood that, without departing from the spirit of the present invention, the present invention can be further modified and changed, and these modifications and changes are within the protection scope of the present invention .

Claims (10)

1. compound, it has following structure

Wherein: R₁, R₂, R₃And R₄For hydrogen atom, straight or branched alkyl, straight or branched alkoxyl, sulfonic group, ester group, carboxyl； R₁, R₂, R₃And R₄Can be identical or different.

Compound the most according to claim 1, it is the compound of following structure:

3., for detecting inorganic mercury and the preparation of organic mercury content in sample, it comprises the compound with following structure:

Wherein: R₁, R₂, R₃And R₄For hydrogen atom, straight or branched alkyl, straight or branched alkoxyl, sulfonic group, ester group, carboxyl； R₁, R₂, R₃And R₄Can be identical or different.

Preparation the most according to claim 3, wherein said compound is:

Preparation the most according to claim 3, wherein said sample is river sample.

6., for detecting inorganic mercury and the test kit of organic mercury content in sample, it comprises the compound with following structure:

Wherein: R₁, R₂, R₃And R₄For independently selected from by hydrogen atom, straight or branched alkyl, straight or branched alkoxyl, sulfonic acid Base, ester group and the group of hydroxyl composition；And R therein₁, R₂, R₃And R₄Can be identical or different.

Test kit the most according to claim 6, wherein said compound is:

Test kit the most according to claim 6, wherein said sample is river sample.

9., according to the test kit according to any one of claim 6-8, it also includes operation instructions.

10., according to the test kit according to any one of claim 6-8, it also includes for detecting mercury ion content in sample Buffer agent.