Method for quantitatively detecting L-tartaric acid

Abstract

The invention relates to a method for quantitatively detecting L-tartaric acid, which is characterized in that a Na2SO3-NaBrO3-K4Fe (CN) 6-H2SO4 clock system, namely a BSF clock reaction system is used as a detection solution, and L-tartaric acid with different concentrations is quantitatively detected according to different responses, namely different induction times, of the system to the L-tartaric acid with different concentrations. The induction time difference delta t is also different (delta t is equal to the induction time of the clock system without adding the L-tartaric acid solution minus the induction time of the clock system after adding the L-tartaric acid solution), and quantitative analysis of the L-tartaric acid is realized. The quantitative analysis method for the L-tartaric acid has the characteristics of high accuracy, easiness in operation, convenience, rapidness and the like.

Description

Technical Field

[0001] The invention relates to an analysis and detection method, specifically to establishing a "Na2SO3-NaBrO3-K4Fe(CN)6-H2SO4" clock system, namely a BSF clock reaction system, and realizing a quantitative analysis method for L-tartaric acid according to the different responses of the system to different concentrations of L-tartaric acid, namely different induction times, and different induction time differences Δt (Δt=induction time of the clock system without adding L-tartaric acid solution-induction time of the clock system after adding L-tartaric acid solution), belonging to the field of analytical chemistry. Background Art

[0002] L-Tartaric acid (its structure is shown in formula (I)), also known as 2,3-dihydroxysuccinic acid. L-Tartaric acid is widely used as an acidulant for beverages and other foods, and is used in wine, soft drinks, candy, bread, and certain jelly-like sweets. Its optical activity is used as a chemical resolving agent for the resolving of DL-aminobutanol, an intermediate in the manufacture of anti-tuberculosis drugs; it can also be used as a chiral raw material for the synthesis of tartaric acid derivatives; its acidity is used as a catalyst for polyester fabric resin finishing and a pH regulator for oryzanol production; its complexing property is used as a complexing agent, masking agent, chelating agent, and anti-dyeing agent in electroplating, desulfurization, pickling, chemical analysis, and medical testing; its reducing property is used as a reducing agent in chemical mirror making.

[0003] The determination methods of L-tartaric acid mainly include high performance liquid chromatography (HPLC) and spectrophotometry. Chromatography has the advantages of high sensitivity and good accuracy, but the analytical sensitivity is reduced for samples with complex matrices. Therefore, it is very necessary to find a detection and analysis method with good detection effect, simple operation and fast operation.

[0004]

[0005] Structural formula (Ⅰ) L-tartaric acid Summary of the invention

[0006] The present invention aims to provide a new quantitative detection method for L-tartaric acid, that is, a method for quantitatively detecting L-tartaric acid using the "Na2SO3- NaBrO3-K4Fe(CN)6 -H2SO4" BSF clock system as a detection solution. The method is a standard curve (working curve) method developed based on the sensitive response of the BSF clock system to L-tartaric acid. Specifically, the "Na2SO3- NaBrO3-K4Fe(CN)6 -H2SO4" BSF clock reaction system is used as a detection solution to record the pH change over time; when the BSF clock reaction starts, a series of L-tartaric acid sample solutions of different concentrations to be detected are added to the BSF clock system in equal volumes; according to the different concentrations of the solution to be detected in the BSF clock system, the induction time generated by the system is different, and the induction time difference Δt is also different, so as to achieve quantitative detection of the L-tartaric acid sample to be detected.

[0007] The induction time of the clock system without adding the L-tartaric acid solution to be tested and the induction time of the clock system after adding the L-tartaric acid solution to be tested were measured respectively, and the induction time difference Δt was obtained. According to the relationship between the concentration of L-tartaric acid in the BSF clock system and the induction time difference Δt, a working curve was established, in which the abscissa is the concentration of L-tartaric acid in the BSF clock system and the ordinate is the induction time difference Δt. When the concentration of L-tartaric acid in the system is 2.5×10 -3 mol / L to 7.5×10 -3 mol / L, the induction time difference Δt is linearly related to the concentration of L-tartaric acid, based on which the quantitative detection of L-tartaric acid in the sample can be achieved.

[0008] The difference between this quantitative detection method and the prior art is that the present invention uses the "Na2SO3-NaBrO3-K4Fe(CN)6-H2SO4" BSF clock system as the detection solution, and the system responds differently to different concentrations of L-tartaric acid, that is, the induction time is different, and the induction time difference Δt is also different, thereby realizing quantitative analysis of L-tartaric acid.

[0009] The concentration range of L-tartaric acid in the test solution (BSF clock system) was 2.5×10 -3 mol / L to 7.5×10 -3 mol / L.

[0010] When L-tartaric acid was detected in the detection solution (BSF clock system), the temperature of the BSF clock system was controlled at 22±0.5°C.

[0011] Using the above BSF clock system, the concentration range in which L-tartaric acid can be detected is the optimal concentration range determined by experiments. Within this concentration range, the induction time difference Δt has a good response to the change in L-tartaric acid concentration, and the linear correlation coefficient is large. In addition, the concentration range of each component in the detection solution (BSF clock system) is shown in Table 1, and the optimal concentration of the detection solution (BSF clock system) obtained after multiple experiments is shown in Table 2: Table 1: Concentrations of components in the BSF clock system <![CDATA[Na2SO3(mol / L)]]> <![CDATA[NaBrO3(mol / L)]]> <![CDATA[K4Fe(CN)6(mol / L)]]> <![CDATA[H2SO4(mol / L)]]> 0.0615-0.0795 0.0525-0.0675 0.0162-0.025 0.0084-0.0147 Table 2: Optimal concentrations of components in the BSF clock system <![CDATA[Na2SO3(mol / L)]]> <![CDATA[NaBrO3(mol / L)]]> <![CDATA[K4Fe(CN)6(mol / L)]]> <![CDATA[H2SO4(mol / L)]]> 0.075 0.0625 0.02 0.0105 The specific experimental steps are as follows: 1. Prepare the test solution (BSF clock system) according to the concentration range specified in Table 1, and its temperature is controlled at 22±0.5℃; insert the prepared working electrode (pH composite electrode, Leici, E-331) into the solution, and connect the other end of the working electrode to the computer through the potential / temperature / pH comprehensive tester (Jiaxing Disheng Electronic Technology Co., Ltd., ZHFX-595). Open the chemical signal acquisition and analysis program in the computer to set the acquisition time and sampling speed, and quickly click the start button to monitor the pH of the solution. The computer records the curve of the pH change over time, that is, the BSF clock spectrum. When the substance needs to be detected, the substance to be detected is quickly added at the same time as the BSF clock system reaction starts, and the BSF clock spectrum of pH change over time is recorded in the same way.

[0012] The basic parameters of the BSF clock spectrum include: Induction time: the time required from the start of the BSF clock system reaction to pH stabilization.

[0013] pH jump range: the pH corresponding to the start of the pH jump in the system to the pH corresponding to the end of the pH jump.

[0014] The induction time difference Δt after the clock system is finally stabilized (Δt = the induction time of the clock system without adding L-tartaric acid solution - the induction time of the clock system after adding L-tartaric acid solution).

[0015] Establishing the working curve between the concentration of L-tartaric acid in the test solution and the induction time difference Δt Distilled water was used as solvent to prepare L-tartaric acid solutions with concentrations of 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, and 3 mol / L as sample solutions. At the start of the BSF clock system reaction, 100 μL of the sample solutions of different concentrations were added to 40 mL of the BSF clock system using a pipette, so that the L-tartaric acid concentration in the system was 2.5×10 -3 mol / L - 7.5×10 -3 mol / L; the change in the response of the BSF clock system is the induction time, recorded as t; when the concentration of L-tartaric acid in the system is different, the induction time t of the BSF clock system is also different, and the difference in induction time Δt is also different (Δt = the induction time of the clock system without adding L-tartaric acid solution - the induction time of the clock system after adding L-tartaric acid solution); the L-tartaric acid concentration in the system is used as the horizontal axis and Δt is used as the vertical axis to draw a graph; when the L-tartaric acid concentration in the system is between 2.5×10 -3 mol / L - 7.5×10 -3 mol / L, the induction time difference Δt of the BSF clock system is in a linear relationship with the concentration of L-tartaric acid, and a working curve is obtained.

[0016] Quantitative detection of L-tartaric acid When a test sample of unknown concentration is added to the detection solution BSF clock system at the beginning of the BSF clock system reaction, the induction time (t) of the corresponding BSF clock system can be measured, and then Δt can be obtained. According to the corresponding relationship between Δt and concentration on the working curve, the concentration of L-tartaric acid in the detection system can be obtained, and then the concentration of L-tartaric acid in the test sample can be calculated. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a graph showing the change in pH value of the test solution (BSF clock system) over time when no sample to be tested is added in Example 1.

[0018] Figure 2 In Example 1, 2.5 × 10 -3 Spectrum of pH value change of the test solution (BSF clock system) over time after addition of 1 mol / L L-tartaric acid.

[0019] Figure 3 In Example 1, 3.75 × 10 -3 Spectrum of pH value change of the test solution (BSF clock system) over time after addition of 1 mol / L L-tartaric acid.

[0020] Figure 4 This is the working curve between the pH induction time difference Δt and the L-tartaric acid concentration in Example 1.

[0021] Figure 5 This is a graph showing the change in pH value of the test solution (BSF clock system) over time when no sample to be tested is added in Example 2.

[0022] Figure 6 In Example 2, 5 × 10 -3 Spectrum of pH value change of the test solution (BSF clock system) over time after addition of 1 mol / L L-tartaric acid.

[0023] Figure 7 In Example 2, 6.25 × 10 -3 Spectrum of pH value change of the test solution (BSF clock system) over time after addition of 1 mol / L L-tartaric acid.

[0024] Figure 8 This is the working curve between the pH induction time difference Δt and the L-tartaric acid concentration in Example 2.

[0025] Fig. 9 This is a graph showing the change in pH value of the test solution (BSF clock system) over time when no sample to be tested is added in Example 3.

[0026] Fig.10 In Example 3, 6.25×10 -3 Spectrum of pH value change of the test solution (BSF clock system) over time after addition of 1 mol / L L-tartaric acid.

[0027] Fig.11 In Example 3, 7.5 × 10 -3 Spectrum of pH value change of the test solution (BSF clock system) over time after addition of 1 mol / L L-tartaric acid.

[0028] Fig.12 This is the working curve between the pH induction time difference Δt and the L-tartaric acid concentration in Example 3. DETAILED DESCRIPTION Example 1

[0029] The BSF clock system with "Na2SO3- NaBrO3-K4Fe(CN)6 -H2SO4" as the substrate was used as the detection solution to quantitatively analyze L-tartaric acid. The equal volume of L-tartaric acid sample solutions with different concentrations were added to the BSF clock system, and a working curve (such as a linear relationship) was established between the L-tartaric acid concentration in the detection system and the induction time difference, so as to achieve the purpose of detecting L-tartaric acid in the BSF clock system, and then calculate the concentration of L-tartaric acid in the test sample.

[0030] (1) Preparation of test solution First, use distilled water to prepare 0.3 mol / L Na2SO3 solution, 0.25 mol / L NaBrO3 solution, 0.08 mol / L K4Fe(CN)6 solution and 0.042 mol / L H2SO4 solution respectively. Into a 50 mL small beaker, add 10 mL of 0.3 mol / L Na2SO3 solution, 10 mL of 0.25 mol / L NaBrO3 solution, 10 mL of 0.08 mol / L K4Fe(CN)6 solution and 10 mL of 0.042 mol / L H2SO4 solution in sequence to ensure that the concentrations of each component in the "Na2SO3- NaBrO3-K4Fe(CN)6 -H2SO4" BSF clock system are Na2SO3 0.075 mol / L, NaBrO3 0.0625 mol / L, K4Fe(CN)6 0.02 mol / L, H2SO4 0.0105 mol / L, with a total volume of 40 mL, and the temperature is controlled at 22°C.

[0031] At the same time, distilled water was used as the solvent to prepare a series of L-tartaric acid sample solutions with different concentrations.

[0032] (2) Obtaining the BSF clock spectrum The graph of the pH value of the prepared test solution changing with time is recorded by a computer equipped with a chemical signal acquisition and analysis program (without adding the test sample), such as Figure 1 As shown. The pH induction time was 308 s, which was used as a blank control. Two other test solutions were prepared with the same concentration of each component as the above test solution. For one of the groups, at the beginning of the reaction, 100 μL of 1 mol / L L-tartaric acid sample solution was added to 40 mL of BSF clock system, so that the concentration of L-tartaric acid in the test solution was 2.5 × 10 -3 mol / L, the addition of L-tartaric acid shortened the induction time to 213 s (the induction time difference Δt was 95 s). Figure 2 As shown; for the other group, at the beginning of the reaction, 100 μL of 1.5 mol / L L-tartaric acid sample solution was added to 40 mL of BSF clock system, so that the concentration of L-tartaric acid in the detection solution was 3.75 × 10 -3 mol / L, the added L-tartaric acid makes the induction time become 188 s (the induction time difference Δt is 120 s), such as Figure 3 shown. Figure 2 , Figure 3 It was confirmed that different concentrations of L-tartaric acid in the detection solution resulted in different induction times for the BSF clock system, and the induction time difference Δt was also different.-3 mol / L - 7.5×10 -3 mol / L, the different induction time differences Δt in the BSF clock system caused by different concentrations can be observed.

[0033] (3) Quantitative detection A working curve was established based on the relationship between the concentration of L-tartaric acid in the detection system and the difference in induction time, such as Figure 4 As shown in the figure, the horizontal axis is the concentration of L-tartaric acid in the BSF clock system, and the vertical axis is the induction time difference Δt. When the concentration of L-tartaric acid in the detection system is 2.5×10 -3 mol / L - 7.5×10 -3 When the induction time difference is between 1.5 and 2.0 mol / L, the induction time difference is linearly related to the concentration of L-tartaric acid, and the linear equation is Δt = 16960c + 54.6,R 2 = 0.9972. Based on this, the quantitative detection of L-tartaric acid in the sample can be achieved. Example 2

[0034] (1) Preparation of test solution First, use distilled water to prepare 0.3 mol / L Na2SO3 solution, 0.25 mol / L NaBrO3 solution, 0.08 mol / L K4Fe(CN)6 solution and 0.042 mol / L H2SO4 solution respectively. Into a 50 mL small beaker, add 9.5 mL of 0.3 mol / L Na2SO3 solution, 9.2 mL of 0.25 mol / L NaBrO3 solution, 9.3 mL of 0.08 mol / L K4Fe(CN)6 solution and 12 mL of 0.042 mol / L H2SO4 solution in sequence to ensure that the concentrations of each component in the "Na2SO3- NaBrO3-K4Fe(CN)6 -H2SO4" BSF clock system are Na2SO3 0.07125 mol / L, NaBrO3 0.0575 mol / L, K4Fe(CN)6 0.0186 mol / L, H2SO4 0.0126 mol / L, with a total volume of 40 mL. The temperature is controlled at 22°C.

[0035] At the same time, distilled water was used as the solvent to prepare a series of L-tartaric acid sample solutions with different concentrations.

[0036] (2) Obtaining the BSF clock spectrum The graph of the pH value of the prepared test solution changing with time is recorded by a computer equipped with a chemical signal acquisition and analysis program (without adding the test sample), such as Figure 5As shown. The pH induction time was 310 s, which was used as a blank control. Two other test solutions were prepared with the same concentration of each component as the above test solution. For one of the groups, at the beginning of the reaction, 100 μL of 2 mol / L L-tartaric acid sample solution was added to 40 mL of BSF clock system, so that the concentration of L-tartaric acid in the test solution was 5 × 10 -3 mol / L, the addition of L-tartaric acid shortened the induction time to 168 s (the induction time difference Δt was 142 s). Figure 6 As shown; for the other group, at the beginning of the reaction, 100 μL of 2.5 mol / L L-tartaric acid sample solution was added to 40 mL of BSF clock system, so that the concentration of L-tartaric acid in the detection solution was 6.25 × 10 -3 mol / L, the added L-tartaric acid makes the induction time become 146 s (the induction time difference Δt is 164 s), such as Figure 7 shown. Figure 6 , Figure 7 It was confirmed that different concentrations of L-tartaric acid in the detection solution resulted in different induction times for the BSF clock system, and the induction time difference Δt was also different. -3 mol / L - 7.5×10 -3 mol / L, the different induction time differences Δt in the BSF clock system caused by different concentrations can be observed.

[0037] (3) Quantitative detection A working curve was established based on the relationship between the concentration of L-tartaric acid in the detection system and the difference in induction time, such as Figure 8 As shown in the figure, the horizontal axis is the concentration of L-tartaric acid in the BSF clock system, and the vertical axis is the induction time difference Δt. When the concentration of L-tartaric acid in the detection system is 2.5×10 -3 mol / L - 7.5×10 -3 When the induction time difference is between 1.5 and 2.0 mol / L, the induction time difference is linearly related to the concentration of L-tartaric acid, and the linear equation is Δt = 16640c + 55,R 2 = 0.9976. Based on this, the quantitative detection of L-tartaric acid in the sample can be achieved. Example 3

[0038] (1) Preparation of test solution First, use distilled water to prepare 0.3 mol / L Na2SO3 solution, 0.25 mol / L NaBrO3 solution, 0.08 mol / L K4Fe(CN)6 solution and 0.042 mol / L H2SO4 solution respectively. Into a 50 mL small beaker, add 9 mL of 0.3 mol / L Na2SO3 solution, 9 mL of 0.25 mol / L NaBrO3 solution, 11 mL of 0.08 mol / L K4Fe(CN)6 solution and 11 mL of 0.042 mol / L H2SO4 solution in sequence to ensure that the concentrations of each component in the "Na2SO3- NaBrO3-K4Fe(CN)6 -H2SO4" BSF clock system are Na2SO3 0.0675 mol / L, NaBrO3 0.05625 mol / L, K4Fe(CN)6 0.022 mol / L, H2SO4 0.01155 mol / L, with a total volume of 40 mL. The temperature is controlled at 22°C.

[0039] At the same time, distilled water was used as the solvent to prepare a series of L-tartaric acid sample solutions with different concentrations.

[0040] (2) Obtaining the BSF clock spectrum The graph of the pH value of the prepared test solution changing with time is recorded by a computer equipped with a chemical signal acquisition and analysis program (without adding the test sample), such as Fig. 9 As shown. The pH induction time was 307 s, which was used as a blank control. Two other test solutions were prepared with the same concentration of each component as the above test solution. For one of the groups, at the beginning of the reaction, 100 μL of 2.5 mol / L L-tartaric acid sample solution was added to 40 mL of BSF clock system, so that the concentration of L-tartaric acid in the test solution was 6.25 × 10 -3 mol / L, the addition of L-tartaric acid shortened the induction time to 148 s (the induction time difference Δt was 159 s). Fig.10 As shown; for the other group, at the beginning of the reaction, 100 μL of 3 mol / L L-tartaric acid sample solution was added to 40 mL of BSF clock system, so that the concentration of L-tartaric acid in the detection solution was 7.5 × 10 -3 mol / L, the added L-tartaric acid makes the induction time become 128 s (the induction time difference Δt is 179 s), such as Fig.11 shown. Fig.10 , Fig.11 It was confirmed that different concentrations of L-tartaric acid in the detection solution resulted in different induction times for the BSF clock system, and the induction time difference Δt was also different. -3mol / L - 7.5×10 -3 mol / L, the different induction time differences Δt in the BSF clock system caused by different concentrations can be observed.

[0041] (3) Quantitative detection A working curve was established based on the relationship between the concentration of L-tartaric acid in the detection system and the difference in induction time, such as Fig.12 As shown in the figure, the horizontal axis is the concentration of L-tartaric acid in the BSF clock system, and the vertical axis is the induction time difference Δt. When the concentration of L-tartaric acid in the detection system is 2.5×10 -3 mol / L - 7.5×10 -3 When the induction time difference is between 1.0 and 2.0 mol / L, the induction time difference is linearly related to the concentration of L-tartaric acid, and the linear equation is Δt = 16640c + 54.2,R 2 = 0.9952. Based on this, the quantitative detection of L-tartaric acid in the sample can be achieved.

Claims

1. A method for quantitatively detecting L-tartaric acid, characterized in that: Using distilled water as solvent, prepare a solution of L-tartaric acid of the sample to be tested; The "Na2SO3- NaBrO3-K4Fe(CN)6 -H2SO4" BSF clock reaction system was used as the detection solution, and the pH change over time was recorded. The temperature of the BSF clock system was controlled within the range of 22±0.5℃. When the BSF clock reaction started, a series of L-tartaric acid solutions of the sample to be detected with equal volumes and different concentrations were added to the BSF clock system. According to the different induction times of the system when the concentration of the solution to be detected in the BSF clock system was different, the quantitative detection of the sample to be detected was achieved: the induction time of the clock system without the addition of L-tartaric acid solution to be detected and the induction time of the clock system after the addition of L-tartaric acid solution to be detected were measured respectively, and the induction time difference Δt was obtained. According to the relationship between the concentration of L-tartaric acid in the solution to be detected in the BSF clock system and the induction time difference Δt, a working curve was established, in which the horizontal axis was the concentration of L-tartaric acid in the solution to be detected in the BSF clock system, and the vertical axis was the induction time difference Δt. When the concentration of L-tartaric acid in the system was 2.5×10 -3 mol / L to 7.5×10 -3 When the induction time difference Δt is between 1.04 and 1.03 mol / L, there is a linear relationship between the induction time difference Δt and the concentration of L-tartaric acid, thereby realizing the quantitative detection of L-tartaric acid in the sample; The molar concentration ranges of the components in the test solution are: Na2SO3 0.0615-0.0795 mol / L, NaBrO3 0.0525-0.0675 mol / L, K4Fe(CN)6 0.0162-0.025 mol / L, H2SO4 0.0084-0.0147 mol / L.

2. The method according to claim 1, characterized in that: The molar concentrations of the components in the test solution are Na2SO3 0.075 mol / L, NaBrO3 0.0625 mol / L, K4Fe(CN)6 0.02 mol / L, and H2SO4 0.0105 mol / L.

3. The method according to claim 1, characterized in that: The temperature of the BSF clock system was controlled at 22°C when detecting the L-tartaric acid solution.

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