TWI745728B - Method for detecting alkali gold and alkaline earth metal ions, and composition for detecting alkali gold and alkaline earth metal ions and preparation method thereof - Google Patents

Abstract

A method for detecting alkali gold and alkaline earth metal ions, including: providing a detection composition, including a plurality of gold nanoparticles with a surface modified by ascorbic acid molecules; After the composition is mixed, the first color is presented; a color card combination is provided, the first color is compared with the color card combination, and one of the excellent cards is the same or the closest to the first color, and is obtained from the color card The type name and concentration value of the alkali metal ion or alkaline earth metal ion in the solution to be tested. A preparation method for a composition for detecting alkali gold and alkaline earth metal ions and a preparation method for a composition for detecting alkali gold and alkaline earth metal ions are also disclosed herein.

Description

Method for detecting alkali gold and alkaline earth metal ions, and composition for detecting alkali gold and alkaline earth metal ions and preparation method thereof

The present invention is related to the detection method of metal ions, in particular to the detection method of alkali gold and alkaline earth metal ions, and the composition for detecting alkali gold and alkaline earth metal ions and the preparation method thereof.

Generally, the types and concentrations of metal ions are mostly analyzed and identified by specific instruments; take atomic spectrometer as an example, which uses the absorption or emission spectra generated by the electrons of metal atoms when they absorb energy and release energy to achieve analysis and identification. The purpose of the type of test object. In the field of chemical instrument analysis, atomic absorption spectroscopy is mainly used to determine the concentration of specific elements in the solution, while for solid samples, the solution can be analyzed by atomic absorption spectroscopy. According to research, there are currently more than 70 elements that can be detected by atomic absorption spectroscopy. Atomic absorption spectroscopy has been widely used in different fields. In addition to detecting the types of elements in the environment, it can also be applied to the analysis of trace elements in biological tissues and the detection of metal elements in market products.

For example, sodium (Na) emits a golden yellow flame when it burns, while magnesium (Mg) emits a strong white light when it burns. In addition, when the analyte contains magnesium or calcium ions, it can be analyzed and identified by titration. For example, magnesium and calcium ions can be detected and analyzed by ethylenediaminetetraacetic acid (EDTA) or aqueous carbonate solution.

However, the aforementioned atomic spectrometers and titration methods can only be used to detect and analyze metal ions in specific chemical analysis laboratories. Therefore, they are limited by the detection and analysis environment, so that the detection and analysis of metal ions cannot be performed instantly and easily.

In summary, the existing detection methods for metal ions still have room for improvement.

In view of this, the object of the present invention is to provide a method for detecting alkali gold and alkaline earth metal ions, which can directly mix the solution to be tested with the detection composition and present a color, and then combine the color with the color card to perform By comparison, the color card with the closest color is used to determine the type, name and concentration value of the alkali metal ion or alkaline earth metal ion in the solution to be tested.

In order to achieve the above-mentioned object, the present invention provides a method for detecting alkali gold and alkaline earth metal ions, including: providing a detection composition, the detection composition includes a plurality of gold nanoparticles modified by the ascorbic acid molecule surface ; Mix a test solution with the test composition, the test solution includes alkali metal ions, alkaline earth metal ions, or a combination thereof, when the test solution is mixed with the test composition, it presents a first color ; Provide a color card combination, the color card combination includes a plurality of color cards, the color of each color card is different from the other color cards, and each of the color cards has an alkali gold metal ion or an alkaline earth metal ion type Name and a concentration value; compare the first color with the color card combination, and compare one of the color cards to be the same or the closest to the first color, and the color card obtains the waiting The type name and concentration value of the alkali gold metal ion or the alkaline earth metal ion contained in the test solution.

Another aspect of the present invention is to provide a composition for detecting alkali gold and alkaline earth metal ions, which includes a plurality of gold nano particles, the weight percentage of which is 0.001 wt% to 2 wt%; and a plurality of ascorbic acid molecules , The weight percentage is less than or equal to 30 wt%; wherein, the ascorbic acid molecules are respectively bound to the surface of the gold nano particles to form a plurality of gold nano particles whose surface is modified by the ascorbic acid molecules.

Another aspect of the present invention is to provide a method for preparing a composition for detecting alkali gold and alkaline earth metal ions, comprising: providing a chloroauric acid (HAuCl4) aqueous solution; adding sodium citrate and the chloroauric acid aqueous solution to perform Reacting to form an aqueous solution of gold nanoparticles; mixing the aqueous solution of gold nanoparticles with an aqueous solution of ascorbic acid to react, so that the plurality of ascorbic acid molecules in the aqueous solution of ascorbic acid are combined with the plurality of gold nanoparticles in the aqueous solution of gold nanoparticles. On the surface of the nanoparticle to obtain the composition, wherein the composition includes a plurality of gold nanoparticles whose surface is modified by the ascorbic acid molecules.

The effect of the present invention is that the prepared detection composition can be used to directly mix the solution to be tested with the detection composition; when the solution to be tested is mixed with the detection composition, a color appears. Compare the color with the color card combination, and compare one of the excellent cards with the same or the closest color, and the information on the color card can determine the alkali metal ions or alkalis in the solution to be tested The type name and concentration value of the earth metal ions. Therefore, the detection method provided by the present invention is not limited to the detection and analysis environment, and the detection and analysis of metal ions can be performed immediately and simply.

In order to explain the present invention more clearly, a preferred embodiment is given in conjunction with the drawings in detail as follows. Figure 1 is a flow chart of a method for preparing a composition for detecting alkali gold and alkaline earth metal ions according to a preferred embodiment of the present invention. The preparation method of the composition for detecting alkali gold and alkaline earth metal ions includes at least the following steps: Step 101: Provide a chloroauric acid (HAuCl4) aqueous solution. In the embodiment of the present invention, the concentration range of the chloroauric acid aqueous solution is 0.3~0.7 mM, preferably 0.5 mM; in the embodiment of the present invention, the chloroauric acid aqueous solution is ^{heated at 100 o} C~105 ^o C for 12 to 18 minutes; Step 102: adding sodium citrate and chloroauric acid aqueous solution the reaction to form an aqueous solution of gold nanoparticles, for example, the aqueous-based gold nanoparticles through 100 ^o C ~ 105 ^o C heating 12 to 18 minutes and then cooled to room temperature in the embodiment of the present invention; and step 103: the Chennai The rice particle aqueous solution is mixed with the ascorbic acid aqueous solution to react, so that the plural ascorbic acid molecules in the ascorbic acid aqueous solution are combined on the surface of the plural gold nanoparticles in the gold nanoparticle aqueous solution to obtain the composition, as shown in the following formula (1)~ As shown in (3); wherein the composition includes a plurality of gold nano particles whose surface has been modified by ascorbic acid molecules. In the embodiment of the present invention, the concentration of the ascorbic acid aqueous solution ranges from 8 to 12 wt%, preferably 10 wt%. _{^{HAuCl 4 → Au 3+ + 4Cl -}} + H +. . Formula (1) Na ₃ C ₆ H ₅ O ₇ → 3Na ⁺ + C ₆ H ₅ O ₇ ^3- . . Formula (2) 3HAuCl ₄ +2Na ₃ C ₆ H ₅ O ₇ → 3Au ⁺ +2C ₆ H ₅ O ₇ ^3- +6NaCl+3Cl ₂ +3H ⁺ . . Formula (3)

In step 103, the volume ratio of the gold nanoparticle aqueous solution to the ascorbic acid aqueous solution ranges from 1:0.8 to 1:1.2, preferably 1:1. Taking the volume ratio of gold nanoparticle aqueous solution to ascorbic acid aqueous solution of 1:1 as an example, the weight percentage of ascorbic acid molecules is less than or equal to 30 wt%, preferably less than or equal to 15 wt%, more preferably 7.5 wt% to 12.5 wt%; In the embodiment of the present invention, the weight percentage of the ascorbic acid aqueous solution is 10 wt%. In step 103, the total content of ascorbic acid molecules in the composition is less than or equal to 10 wt%, preferably 3 wt% to 7 wt%.

Fig. 2 is an ultraviolet light/visible light spectroscopic diagram of gold nanoparticles reduced by sodium citrate according to a preferred embodiment of the present invention. It can be seen from Fig. 2 that the gold nanoparticle aqueous solution formed in step 102 contains gold nanoparticle reduced by sodium citrate, and the absorption peak of the ultraviolet light/visible light spectrum falls at about 525 nm.

Fig. 3 is a bar graph of the particle size distribution of gold nanoparticles reduced by sodium citrate according to a preferred embodiment of the present invention. It can be seen from Figure 3 that the average particle size of the gold nanoparticle formed in step 102 is about 15.75 nm.

Fig. 4 is a bar graph of the particle size distribution of gold nanoparticles modified with ascorbic acid according to a preferred embodiment of the present invention. It can be seen from Figure 4 that the average particle size of the gold nanoparticle with ascorbic acid molecule modified surface formed in step 103 increases to about 20.8 nm, which indicates that the ascorbic acid molecule does bind to the modified surface of the gold nanoparticle, so that the surface modified The average particle size of the gold nanoparticle increases.

Fig. 5 is an infrared spectrogram of gold nanoparticles modified with ascorbic acid according to a preferred embodiment of the present invention. From the infrared spectrum of Figure 5, it can be seen that the carbon-hydrogen bond (CH ₃ ) and carbon-oxygen bond (CO and C=O) penetration rates of the gold nanoparticles on the surface modified by ascorbic acid molecules formed in step 103 are significantly enhanced. It means that the ascorbic acid molecule does bind to the modified surface of the gold nanoparticle, so the surface-modified gold nanoparticle _{penetrates the carbon-hydrogen bond (CH 3} ) and carbon-oxygen bond (CO and C=O) in the infrared spectrum Increased rate.

Fig. 6 is a flow chart of a method for detecting alkali gold and alkaline earth metal ions according to a preferred embodiment of the present invention. The method for detecting alkali gold and alkaline earth metal ions includes at least the following steps: Step 601: Provide a detection composition, and the detection composition includes a plurality of gold nanoparticles whose surface has been modified by ascorbic acid molecules; Step 602: Mix the test solution with the test composition. The test solution includes alkali metal ions, alkaline earth metal ions, or a combination thereof. When the test solution is mixed with the test composition, the first color appears; and Step 603: Provide a color card combination. The color card combination includes a plurality of color cards. The color of each color card is different from other color cards, and each color card has the type name and concentration value of alkali metal ion or alkaline earth metal ion; A color is compared with a color card combination, and one of the compared excellent cards is the same or the closest to the first color, and the color card is used to obtain the alkali metal ion or alkaline earth metal ion of the test solution. Type name and concentration value.

According to an embodiment of the present invention, the aforementioned composition for detecting alkali gold and alkaline earth metal ions includes gold nanoparticles, the weight percentage of which is 0.001 wt% to 2 wt%; and ascorbic acid molecules, the weight percentage of which is less than or equal to 30 wt%; wherein the ascorbic acid molecules are respectively bound to the surface of the gold nanoparticle to form the gold nanoparticle with the surface modified by the ascorbic acid molecule. In the embodiment of the present invention, the weight percentage of ascorbic acid molecules is preferably less than or equal to 15 wt%, more preferably 7.5 wt% to 12.5 wt%.

The above composition further includes water, so that the gold nano particles whose surface has been modified by the ascorbic acid molecules are suspended in the water. In the embodiment of the present invention, the content of ascorbic acid molecules in the composition is less than or equal to 10 wt%, preferably 3 wt% to 7 wt%.

In step 602, the volume ratio of the test solution to the test composition ranges from 1:0.05 to 1:20, preferably from 1:0.1 to 1:5, and more preferably from 1:0.2 to 1:1. In step 602, after the test solution is mixed with the test composition, the concentration of the gold nanoparticles on the surface modified by the ascorbic acid molecules ranges from 0.01 mM to 10 mM, more preferably 0.01 mM to 5.0 mM.

According to an embodiment of the present invention, the method for detecting alkali gold and alkaline earth metal ions further includes separating the specific types of alkali gold or alkaline earth metal ions from the solution to be tested by precipitation filtration, or reducing specific types of alkali gold or alkaline earth metal ions. The concentration of alkaline earth metal ions is mixed with the detection composition. In short, for unknown alkali metal and alkaline earth metal ions, if you want to further distinguish the types of mixed metals, you can first use precipitation and filtration to perform preliminary treatments on the test solution to reduce the uncertainty of the composition of the test solution , And then further conduct colorimetric detection for the solution to be tested. For example, if a mixed solution including an unknown concentration of both Ca ^2+, Mg ²⁺ when, through the addition of the alkaline solution may contain a hydroxide of the Mg ²⁺ precipitation, followed by taking the upper end of a clear liquid, then The detection method provided by the embodiment of the present invention is to identify the presence or absence of ^{Ca 2+ and its concentration content.}

FIG. 7 is a schematic diagram of the reaction mechanism of a modified gold nanoparticle with alkali gold or alkaline earth metal ions according to a preferred embodiment of the present invention. In Figure 7, the ascorbic acid molecules bound to the gold nanoparticle have an attractive effect on alkali gold or alkaline earth metal ions, thus shortening the distance between the gold nanoparticle and even causing agglomeration behavior of varying degrees. Since the color of gold nanoparticles is determined by the characteristics of limited surface plasma resonance (SPR), which is very sensitive to the particle size of gold nanoparticles, when alkali gold or alkaline earth metal ions and gold When nano particles form agglomerated structures of different sizes, the agglomerated structures will show different colors and can be directly distinguished by the naked eye. In Figure 7, ascorbic acid molecules (indicated by Y-shape) are bound on the surface of gold nanoparticles, and the ascorbic acid molecules attract alkali gold and alkaline earth metal ions in the test solution to form an agglomerated structure. It can be seen from Figure 7 that as the radius of the alkali gold and alkaline earth metal ions is larger, the color of the agglomerated structure becomes more purple; on the contrary, when the radius of the alkali gold and alkaline earth metal ions is smaller, the agglomerated structure appears The more reddish the color. In the embodiment of the present invention, when the test solution is mixed with the test composition, the ascorbic acid molecules on the surface of the gold nanoparticle interact with the alkali metal ions or alkaline earth metal ions in the test solution to form the above The first color.

FIG. 8 is a visible light absorption spectrum diagram of a modified gold nanoparticle mixed with alkali metal and alkaline earth metal ions in a preferred embodiment of the present invention. ^{Take potassium ions (K +} ) in the alkali gold group, ^{magnesium ions (Mg 2+} ) in the alkaline earth group and the detection reagent (ie composition) as an example. In Figure 8, the absorption peak of the detection reagent is about 525 nm , The absorption peak of the detection reagent after addition of potassium ion (K ⁺ ) is about 541 nm, and the absorption peak of magnesium ion (Mg ²⁺ ) after addition is about 646 nm; it can be seen that when potassium ion (K ⁺ ) and When the detection reagent is mixed to form an agglomerated structure, its agglomeration structure will cause the absorption peak to shift to 541 nm, and when the magnesium ion (Mg ²⁺ ) is mixed with the detection reagent to form an agglomerated structure, the absorption peak of the agglomeration structure will shift more obviously (To 646 nm).

Figure 9 is a colorimetric photo of the modified gold nanoparticle in a preferred embodiment of the present invention for the detection of different concentrations of alkali gold and alkaline earth cations. In Figure 9, with the different types of alkali gold and alkaline earth metals and the change of ion concentration, the color of the agglomeration structure changes. As the concentration of alkali gold and alkaline earth metal ions is higher, the color of the agglomerated structure becomes more bluish-violet; on the contrary, when the concentration of alkali gold and alkaline earth metal ions is lower, the color of the agglomerate structure is more biased. Red. For example, as the concentration of potassium ions (K ⁺ ) increases, the color of the agglomerated structure changes from light red to blue-violet.

In the embodiment of the present invention, the method for detecting alkali gold and alkaline earth metal ions further includes diluting the test solution and mixing it with the test composition; when the diluted test solution is mixed with the test composition, the second Color; compare the second color with the color card combination, and compare the other one of the excellent cards with the same or the closest color to the second color, and obtain the alkali gold metal ions in the solution to be tested from the other color card Or the type name of alkaline earth metal ions and another concentration value. For example, when the first color after mixing the test solution and the test composition is approximately 0.005M Ca ²⁺ ion color and 0.08M K ⁺ ion color, and it is difficult to distinguish, the test solution may be diluted ( For example, it is diluted to three-quarters of the original concentration), and then mixed with the detection composition. When the diluted test solution is mixed with the test composition, the second color appears; the second color is compared with the color card combination, and the other one in the excellent card (for example, 0.06M K ⁺ ion The color) is the same as or the closest to the second color, it can be roughly inferred that the original test solution contains 0.08M K ⁺ ions. Accordingly, with the method for detecting alkali gold and alkaline earth metal ions provided by the embodiments of the present invention, the types and ions of alkali gold and alkaline earth metal ions contained in the test solution can be quickly and simply detected. concentration.

10 is a photo of the color change before and after detection of a sample containing alkali gold or alkaline earth cations of a test piece with modified gold nanoparticles according to a preferred embodiment of the present invention. In Figure 10, the above mixture is made into a test strip, where the test strip appears light red when the sample containing alkali gold or alkaline earth cations is not dropped; when the sample containing alkali gold or alkaline earth cations is dropped After the sample, the test piece is brown. It can be seen that the samples and test strips containing alkali gold or alkaline earth cations will have a significant color change, which can be distinguished by the naked eye.

The design of the embodiment of the present invention is to use the prepared detection composition to directly mix the solution to be tested with the detection composition; when the solution to be tested is mixed with the detection composition, a color appears. Compare the color with the color card combination, and compare one of the excellent cards with the same or the closest color, and the information on the color card can determine the alkali metal ions or alkalis in the solution to be tested The type name and concentration value of the earth metal ions. Therefore, the detection method provided by the present invention is not limited to the detection and analysis environment, and the detection and analysis of metal ions can be performed immediately and simply.

The above are only the preferred and feasible embodiments of the present invention. Any equivalent changes made by applying the specification of the present invention and the scope of the patent application should be included in the patent scope of the present invention.

101, 102, 103, 601, 602, 603: steps

FIG. 1 is a flow chart of a method for preparing a composition for detecting alkali gold and alkaline earth metal ions according to a preferred embodiment of the present invention; Fig. 2 is an ultraviolet/visible spectroscopic diagram of gold nanoparticles reduced by sodium citrate according to a preferred embodiment of the present invention; Figure 3 is a bar graph of the particle size distribution of gold nanoparticles reduced by sodium citrate according to a preferred embodiment of the present invention; 4 is a bar graph of the particle size distribution of gold nanoparticles modified with ascorbic acid according to a preferred embodiment of the present invention; Figure 5 is an infrared spectrogram of gold nanoparticles modified with ascorbic acid according to a preferred embodiment of the present invention; 6 is a flow chart of a method for detecting alkali gold and alkaline earth metal ions according to a preferred embodiment of the present invention; FIG. 7 is a schematic diagram of the reaction mechanism of a modified gold nanoparticle and an alkali metal or alkaline earth metal ion according to a preferred embodiment of the present invention; Fig. 8 is a visible light absorption spectrum of a modified gold nanoparticle mixed with alkali metal and alkaline earth metal ions in a preferred embodiment of the present invention; Figure 9 is a colorimetric photo of the modified gold nanoparticle in a preferred embodiment of the present invention for the detection of different concentrations of alkali gold and alkaline earth cations; 10 is a photo of the color change before and after the detection of a sample containing alkali gold or alkaline earth cations of a test piece with modified gold nanoparticles according to a preferred embodiment of the present invention.

601, 602, 603: steps

Claims (8)

A method for preparing a composition for detecting alkali gold and alkaline earth metal ions, comprising: providing a chloroauric acid (HAuCl ₄ ) aqueous solution with a concentration of 0.3 to 0.7 mM; adding sodium citrate and the chloroauric acid aqueous solution The reaction is carried out by heating at 100-105°C to form an aqueous solution of gold nanoparticles; and the aqueous solution of gold nanoparticles and an aqueous solution of ascorbic acid are mixed at a mixing volume ratio of 1:0.8 to 1:1.2 to react, so that the aqueous solution of ascorbic acid The plurality of ascorbic acid molecules in the gold nanoparticle solution are combined on the surface of the gold nanoparticle in the gold nanoparticle aqueous solution to obtain the composition, wherein the composition includes a plurality of gold nanoparticles whose surface is modified by the ascorbic acid molecules The concentration of the gold nanoparticle on the surface of the particles modified by the ascorbic acid molecules ranges from 0.01 to 10 mM. The method for preparing the composition for detecting alkali gold and alkaline earth metal ions as described in claim 1, wherein the weight percentage of the ascorbic acid molecules is less than or equal to 30 wt%. The method for preparing a composition for detecting alkali gold and alkaline earth metal ions according to claim 1, wherein the content of the ascorbic acid molecules in the composition is less than or equal to 10 wt%. A method for detecting alkali gold and alkaline earth metal ions, comprising: providing a detection composition, the detection composition includes a plurality of gold nanoparticles modified with ascorbic acid molecules on the surface, the gold nanoparticles modified with ascorbic acid molecules on the surface The particles include gold nano particles, the weight percentage of which is 0.001wt% to 2wt%; and the ascorbic acid molecules, the weight percentage of which is less than or equal to 30wt%; Mix a test solution with the test composition, the volume ratio of the test solution to the test composition ranges from 1:0.05 to 1:20, and the test solution includes alkali gold metal ions, alkaline earth metal ions or The combination: when the solution to be tested is mixed with the detection composition, it presents a first color; a color card combination is provided, the color card combination includes a plurality of color cards, and the color of each color card is different from the other color cards , And each color card has an alkali gold metal ion or an alkaline earth metal ion type name and a concentration value; compare the first color with the color card combination, and compare the color cards One of them is the same or the closest to the first color, and the type name and concentration value of the alkali gold metal ion or the alkaline earth metal ion contained in the solution to be tested are obtained from the color card. The method for detecting alkali gold and alkaline earth metal ions according to claim 4, wherein after the solution to be tested is mixed with the detection composition, the concentration range of the gold nanoparticles on the surface modified by the ascorbic acid molecules It is 0.01mM to 10mM. The method for detecting alkali gold and alkaline earth metal ions as described in claim 4, further comprising diluting the test solution and mixing it with the test composition, when the diluted test solution is mixed with the test composition Then, a second color is presented; the second color is compared with the color card combination, and the comparison shows that the other of the color cards is the same as or the closest to the second color, and is determined by the other color. The card obtains the type name of the alkali gold metal ion or the alkaline earth metal ion and the other concentration value of the solution to be tested. The method for detecting alkali gold and alkaline earth metal ions as described in claim 4 further includes separating some kinds of alkali gold or alkaline earth metal ions from the solution to be tested by precipitation filtration, or reducing some kinds of alkali The concentration of gold or alkaline earth metal ions is mixed with the detection composition. The method for detecting alkali gold and alkaline earth metal ions according to claim 4, wherein when the test solution is mixed with the test composition, the ascorbic acid molecules on the surface of the gold nanoparticles and the test solution The alkali gold metal ions or alkaline earth metal ions in the ions function and aggregate to present the first color.

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