Standard substance for ozone detection and preparation method and application thereof

Abstract

The embodiment of the invention discloses a standard substance for ozone detection as well as a preparation method and application thereof, and belongs to the technical field of standard substances. The method comprises the following steps: accurately weighing indigo sodium disulfonate, adding a diluent for dissolving, transferring into a volumetric flask for constant volume, and accurately preparing the standard substance for ozone detection with a standard value of (2000-5000) [mu] g / mL, the diluent comprising acetic acid with a mass concentration of (6.13-11.23) g / L, sodium acetate with a mass concentration of (2.04-13.34) g / L, and sodium hydrogen sulfite with a mass concentration of (1-5) g / L. The standard substance for ozone detection provided by the invention is accurate in mass value, has no unidirectional trend change in characteristic quantity value within one year under a refrigeration storage condition, is good in stability, and ensures the accuracy of a detection result.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of reference materials, and specifically relate to a reference material for ozone detection, a preparation method thereof, and an application thereof. Background Art

[0003] Currently, ozone detection mainly relies on technical means such as chemical analysis methods, electrochemical sensor methods, ultraviolet absorption spectroscopy methods, spectrophotometry methods, etc. China has promulgated a number of standard specifications related to ozone detection, such as "HJ 1225-2021", "HJ 504-2009", and "HJ 590-2010". Therefore, to ensure the accuracy of ozone detection, the preparation of reference materials is an indispensable link.

[0004] The commercially available reference materials for ozone detection have poor stability, and during storage and use, they are easily affected and interfered by factors such as light, temperature, pH value, etc., resulting in inaccurate measurement results. Therefore, researching a preparation method that can prepare a reference material for ozone detection with good stability and accurate quantity values can ensure the accuracy and reliability of relevant detection and analysis results, provide comparable, traceable, and repeatable data for ozone monitoring in the environment, and is of great significance for the implementation of regulations and standards and environmental pollution prevention and control. Summary of the Invention

[0005] For this reason, the embodiments of the present invention provide a reference material for ozone detection, a preparation method thereof, and an application thereof.

[0006] In order to achieve the above object, the embodiments of the present invention provide the following technical solutions:

[0007] According to the first aspect of the embodiments of the present invention, the present invention provides a preparation method of a reference material for ozone detection, and the method includes:

[0008] Accurately weigh indigo disulfonate sodium, dissolve it in a diluent, transfer it to a volumetric flask and make up the volume to a constant volume, and accurately prepare a reference material for ozone detection with a standard value of (2000-5000) μg / mL. Among them, the diluent includes acetic acid with a mass concentration of (6.13-11.23) g / L, sodium acetate with a mass concentration of (2.04-13.34) g / L, and sodium bisulfite with a mass concentration of (1-5) g / L.

[0009] Further, based on 1000 mL of the reference material for ozone detection, the dosage of indigo disulfonate sodium is 19.43125 g to 48.57812 g.

[0010] Further, the pH value of the diluent is 3.6-4.6.

[0011] Further, the purity of the sodium indigodisulfonate is 95% - 100%.

[0012] According to the second aspect of the embodiments of the present invention, the present invention provides a reference material for ozone detection, which is prepared by the preparation method described in any one of the above.

[0013] According to the third aspect of the embodiments of the present invention, the present invention provides the application of the reference material for ozone detection as described above, which is used for the monitoring of ozone in ambient air.

[0014] Further, ozone in ambient air is detected by the spectrophotometry method of "HJ 504 - 2009".

[0015] The embodiments of the present invention have the following advantages:

[0016] (1) In the preparation method of the reference material for ozone detection of the present invention, acetic acid and sodium acetate are added to adjust the pH value of the solution, providing a more stable pH environment for sodium indigodisulfonate, reducing the influence of environmental acidity and alkalinity changes on the detection results, preventing its degradation or deterioration under adverse conditions, and prolonging its storage time.

[0017] (2) In the preparation method of the reference material for ozone detection of the present invention, sodium bisulfite is added, effectively eliminating the interference of oxidizing substances on ozone detection, preventing it from oxidizing sodium indigodisulfonate, and slowing down its decomposition under light conditions, further enhancing the stability of the solution and ensuring the accuracy of the detection results.

[0018] (3) The preparation method of the present invention can prepare a reference material for ozone detection with good stability, making the measurement accuracy higher and the ozone detection process faster and more convenient. Description of the Drawings

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only exemplary, and for those of ordinary skill in the art, without creative efforts, other implementation drawings can be obtained according to the provided drawings.

[0020] Figure 1 It is the flowchart of the preparation method of the reference material for ozone detection provided by the present invention;

[0021] Figure 2 It is the standard curve provided by the present invention;

[0022] Figure 3 It is the stability test chart of the reference material for ozone detection in Examples 1 - 3 and Comparative Examples 1 - 3 of the present invention. Detailed Embodiments

[0023] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0024] Reagents:

[0025] Indigo disulfonate sodium: TCI, 95%;

[0026] Acetic acid: Alfa Aesar, 99.7%;

[0027] Sodium acetate: Energy Chemical, 99%;

[0028] Sodium sulfite: aladdin, 98%;

[0029] In ozone detection, the molar ratio of ozone to indigo disulfonate sodium in the reaction is 1:1.

[0030] Example 1 Standard substance for ozone detection with a standard value of 2000 μg / mL

[0031] This example provides a standard substance for ozone detection with a standard value of 2000 μg / mL, and its preparation method includes the following steps:

[0032] (1) Weigh 12.26 g of acetic acid, 26.68 g of sodium acetate, and 2 g of sodium sulfite, dissolve them in a small amount of pure water in sequence, transfer them to a 2 L volumetric flask, add ultrapure water to the calibration line, mix well, and prepare a dilution solution containing 6.13 g / L of acetic acid, 13.34 g / L of sodium acetate, and 1 g / L of sodium sulfite with a pH value of 4.6.

[0033] (2) Accurately weigh 19.43125 g of indigo disulfonate sodium solid calculated according to 100% purity, add an appropriate amount of the dilution solution prepared in step (1) to dissolve it, transfer it to a 1 L volumetric flask, and make the volume constant with the dilution solution prepared in step (1) to obtain a standard substance for ozone detection with a standard value of 2000 μg / mL.

[0034] Example 2 Standard substance for ozone detection with a standard value of 3000 μg / mL

[0035] This example provides a standard substance for ozone detection with a standard value of 3000 μg / mL, and its preparation method includes the following steps:

[0036] (1)Weigh 19.7 g of acetic acid, 9.78 g of sodium acetate, and 4 g of sodium sulfite, dissolve them in a small amount of pure water in sequence, transfer to a 2 L volumetric flask, add ultrapure water to the calibration line, mix well, and prepare a dilution solution containing 9.85 g / L of acetic acid, 4.89 g / L of sodium acetate, 2 g / L of sodium sulfite, and with a pH value of 4.0.

[0037] (2)Accurately weigh 29.14687 g of indigo disulfonate sodium solid with a purity converted to 100% mass, add an appropriate amount of the dilution solution prepared in step (1) to dissolve it, transfer to a 1 L volumetric flask, and make up the volume with the dilution solution prepared in step (1) to obtain a standard substance for ozone detection with a standard value of 3000 μg / mL.

[0038] Example 3 Standard Substance for Ozone Detection with a Standard Value of 5000 μg / mL

[0039] This example provides a standard substance for ozone detection with a standard value of 5000 μg / mL, and its preparation method includes the following steps:

[0040] (1)Weigh 22.46 g of acetic acid, 4.08 g of sodium acetate, and 10 g of sodium sulfite, dissolve them in a small amount of pure water in sequence, transfer to a 2 L volumetric flask, add ultrapure water to the calibration line, mix well, and prepare a dilution solution containing 11.23 g / L of acetic acid, 2.04 g / L of sodium acetate, 5 g / L of sodium sulfite, and with a pH value of 3.6.

[0041] (2)Accurately weigh 48.57812 g of indigo disulfonate sodium solid with a purity converted to 100% mass, add an appropriate amount of the dilution solution prepared in step (1) to dissolve it, transfer to a 1 L volumetric flask, and make up the volume with the dilution solution prepared in step (1) to obtain a standard substance for ozone detection with a standard value of 5000 μg / mL.

[0042] Comparative Example 1 Standard Substance for Ozone Detection with a Standard Value of 2000 μg / mL

[0043] This comparative example provides a standard substance for ozone detection with a standard value of 2000 μg / mL, and its preparation method includes:

[0044] Accurately weigh 19.43125 g of indigo disulfonate sodium solid with a purity converted to 100% mass, add an appropriate amount of pure water to dissolve it, transfer to a 1 L volumetric flask, and make up the volume with pure water to obtain a standard substance for ozone detection with a standard value of 2000 μg / mL.

[0045] Comparative Example 2 Standard Substance for Ozone Detection with a Standard Value of 2000 μg / mL

[0046] This comparative example provides a standard substance for ozone detection with a standard value of 2000 μg / mL, and its preparation method includes the following steps:

[0047] (1) Weigh 26.6 g of disodium hydrogen phosphate, 22.4 g of citric acid and 2 g of sodium sulfite, dissolve them in a small amount of pure water in sequence, transfer them to a 2 L volumetric flask, add ultrapure water to the calibration line, mix well, and prepare a dilution solution containing 13.3 g / L of disodium hydrogen phosphate, 11.2 g / L of citric acid and 1 g / L of sodium sulfite with a pH value of 4.6.

[0048] (2) Accurately weigh 19.43125 g of indigo disulfonate sodium solid calculated as 100% mass according to purity, add an appropriate amount of the dilution solution prepared in step (1) to dissolve it, transfer it to a 1 L volumetric flask, and make up the volume with the dilution solution prepared in step (1) to obtain a standard substance for ozone detection with a standard value of 2000 μg / mL.

[0049] Comparative Example 3 Standard substance for ozone detection with a standard value of 2000 μg / mL

[0050] This comparative example provides a standard substance for ozone detection with a standard value of 2000 μg / mL, and its preparation method includes the following steps:

[0051] (1) Weigh 12.26 g of acetic acid, 26.68 g of sodium acetate and 2 g of tea polyphenols, dissolve them in a small amount of pure water in sequence, transfer them to a 2 L volumetric flask, add ultrapure water to the calibration line, mix well, and prepare a dilution solution containing 6.13 g / L of acetic acid, 13.34 g / L of sodium acetate and 1 g / L of tea polyphenols with a pH value of 4.6.

[0052] (2) Accurately weigh 19.43125 g of indigo disulfonate sodium solid calculated as 100% mass according to purity, add an appropriate amount of the dilution solution prepared in step (1) to dissolve it, transfer it to a 1 L volumetric flask, and make up the volume with the dilution solution prepared in step (1) to obtain a standard substance for ozone detection with a standard value of 2000 μg / mL.

[0053] Test Example 1

[0054] This test example describes the method for establishing a standard curve. Taking the standard substance for ozone detection with a standard value of 2000 μg / mL prepared in Example 1 as an example, it is diluted to a concentration of 1 μg / mL with the dilution solution prepared in step (1) of Example 1. Respectively take 10 ml, 8 ml, 6 ml, 4 ml, 2 ml, and 0 ml of the 1 μg / mL standard solution into 10 ml colorimetric tubes, and then add 0 ml, 2 ml, 4 ml, 6 ml, 8 ml, and 10 ml of 0.05 mol / L phosphate buffer solution (preparation method: weigh 6.8 g of potassium dihydrogen phosphate and 7.1 g of anhydrous disodium hydrogen phosphate, dissolve in water, and dilute to 1000 ml) to obtain a series of standard working solutions with ozone concentrations of 1.0 μg / mL, 0.8 μg / mL, 0.6 μg / mL, 0.4 μg / mL, 0.2 μg / mL, and 0 μg / mL respectively.

[0055] The above series of standard working solutions were tested by the spectrophotometry method of 《HJ 504-2009》, and the conditions are as follows: use a 20 mm colorimetric cell, use water as the reference, and measure the absorbance at a wavelength of 610 nm.

[0056] Taking the ozone concentration of the standard working solution as the abscissa and the difference between the absorbance of the blank sample and the absorbance of each standard working solution as the ordinate, perform linear regression to obtain the regression equation y = 0.3209x + 0.0006, R 2 > 0.999. The standard curve is shown in Figure 2 。

[0057] Test Example 2

[0058] The stability of the standard substances for ozone detection prepared in Examples 1-3 and Comparative Examples 1-3 was tested by the spectrophotometry method of 《HJ 504-2009》, and the test results are shown in Table 1. The stability test of the standard substances for ozone detection prepared in Examples 1-3 and Comparative Examples 1-3 is as follows Figure 3 。

[0059]

[0060] The results show that the quantity values of the standard substances for ozone detection provided by Examples 1-3 are accurate, and there is no unidirectional trend change in the characteristic quantity values within one year under the storage condition of refrigeration, and the stability is good. Moreover, for the standard substances for ozone detection in Comparative Examples 1-3, the quantity values decrease with the extension of storage time under the storage condition of refrigeration, and the stability is poor.

[0061] Test Example 3 Homogeneity Test

[0062] According to the provisions of JJG 1006-1994 "Technical Specifications for Primary Reference Materials" and JJF 1343-2022 "Certification and Evaluation of Homogeneity and Stability of Reference Materials", the statistical processing of the test results for the homogeneity of reference materials usually adopts the analysis of variance method. In this test example, taking Example 2 as an example, its homogeneity was tested, and the detection was carried out according to the spectrophotometry method of "HJ 504-2009", and the results are shown in Table 2. It can be seen from the results in Table 2 that the homogeneity of this reference material is good.

[0063]

[0064] Test Example 4 Uncertainty Evaluation

[0065] The uncertainty of the reference material for ozone detection in Example 3 was evaluated.

[0066] It was prepared by the gravimetric-volumetric method, and the prepared value was used as the standard value. The uncertainty mainly comes from the purity of raw materials, the solution preparation process, sample inhomogeneity and instability.

[0067] 1. The uncertainty introduced by the purity of raw materials is 0.26%.

[0068] 2. The uncertainty introduced during the solution preparation process is introduced by the weighing on the balance and the volumetric flask volume fixing. Among them, the uncertainty introduced by the weighing on the balance comes from the repeatability of the balance weighing, the indication error of the balance and the buoyancy effect.

[0069] (1) Repeatability error of balance weighing: According to the balance verification certificate, when weighing a sample of 48.57812 g, the maximum allowable repeatability error is 0.15 mg. The net weight of the sample is obtained from 2 weighing operations, and each time is an independent observation result. Its relative standard uncertainty is

[0070] (2) Indication error of balance: According to the balance verification certificate, when weighing a sample of 48.57812 g, the maximum allowable indication error is 0.05 mg. The net weight of the sample is obtained from 2 weighing operations, and each time is an independent observation result. Then the relative standard uncertainty is

[0071] (3) Buoyancy effect: When weighing under normal pressure, the weighing volume is small, and this item can be ignored.

[0072] Therefore, the relative standard uncertainty u 天平rel introduced by the balance is 0.001%.

[0073] The uncertainty introduced by the volumetric flask volume fixing comes from the maximum allowable volume error, volume fixing repeatability and solution temperature effect.

[0074] The volumetric flask used in the solution preparation process is 1000 mL.

[0075] (1) Maximum allowable tolerance of the volumetric flask: As can be seen from the verification certificate of the volumetric flask, the maximum allowable tolerance of a 1000 mL volumetric flask is 0.40 mL. Assuming a uniform distribution, its relative standard uncertainty is:

[0076]

[0077] (2) Repeatability of volume fixing: After filling a 1000 mL volumetric flask to the calibration line and weighing it 10 times repeatedly, the standard deviation is obtained as 0.2 mL, then its relative uncertainty is 0.2 / 1000×100% = 0.020%.

[0078] (3) Temperature effect: The temperature during the preparation of the solution reference material in this experiment varies between ±3 °C. The volume expansion coefficient of acetonitrile is 1.37×10 -3 mL•°C -1 , assuming a uniform distribution, the relative standard uncertainty is:

[0079]

[0080] Combining the above three uncertainty components, the relative standard uncertainty introduced by volume fixing of the volumetric flask is obtained.

[0081] In summary, the relative standard uncertainty introduced by solution preparation

[0082]

[0083] The uncertainty introduced by sample inhomogeneity is 0.0944%.

[0084] The uncertainty introduced by sample instability is 0.34%.

[0085] Combining the above relative uncertainty components, the relative standard uncertainty u rel of the reference material is 0.50%. In the 95% confidence interval, the expanded uncertainty takes the coverage factor k = 2, then the relative expanded uncertainty is 1%.

[0086] Although the present invention has been described in detail with general descriptions and specific embodiments above, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection of the present invention.

Claims

1. A preparation method of a reference material for ozone detection, characterized in that, The method includes: Accurately weigh sodium indigodisulfonate, dissolve it in a diluent, transfer it to a volumetric flask and make up the volume to obtain a standard substance for ozone detection with a standard value of (2000 - 5000) μg / mL. Among them, the diluent includes acetic acid with a mass concentration of (6.13 - 11.23) g / L, sodium acetate with a mass concentration of (2.04 - 13.34) g / L, and sodium bisulfite with a mass concentration of (1 - 5) g / L.

2. The preparation method of the reference material for ozone detection according to claim 1, characterized in that, Based on 1000 mL of the standard substance for ozone detection, the dosage of sodium indigodisulfonate is 19.43125 g - 48.57812 g.

3. The preparation method of the reference material for ozone detection according to claim 1, characterized in that, The pH value of the diluent is 3.6 - 4.

6.

4. The preparation method of the reference material for ozone detection according to claim 1, characterized in that, The purity of the sodium indigodisulfonate is 95% - 100%.

5. A reference material for ozone detection, characterized in that, It is prepared by the preparation method described in any one of claims 1 - 4.

6. The application of the reference material for ozone detection according to claim 5, characterized in that, It is used for the monitoring of ozone in ambient air.

7. The application according to claim 6, characterized in that, Ozone in ambient air is detected by the spectrophotometry method in "HJ 504 - 2009".

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