Method for measuring contents of copper and manganese in Hopcalite

Abstract

The invention relates to the technical field of chemical defense, in particular to a method for measuring the content of copper and manganese in a Hopcalite agent. The method comprises the following steps: performing acid decomposition on a sample, filtering into a solution, introducing a plasma torch flame, exciting a copper element in the solution to emit a characteristic spectral line (wavelength of 324.754 nm) of the copper element and exciting a manganese element in the solution to emit a characteristic spectral line (wavelength of 260.569 nm) of the manganese element under the high-temperature action of plasma, and determining the concentration of the copper element according to the direct proportion relation between the spectral line intensity and the concentration of the solution. The contents of copper and manganese elements can be solved; the method is simple and convenient to operate, accurate and reliable, high in practicability and easy to implement. By measuring the contents of copper and manganese in the Hopcalite, the conversion rate of the preparation raw materials of the Hopcalite can be calculated, so that technical guidance is provided for production and process improvement of the Hopcalite.

Description

Technical Field

[0001] This invention relates to the field of chemical defense technology, specifically to a method for determining the copper and manganese content in hopalat agent. Background Technology

[0002] Hogalat agent is produced by reacting, washing, molding, and activating potassium permanganate, manganese sulfate, concentrated sulfuric acid, sodium carbonate, and copper sulfate in a specific ratio under certain process conditions. It is a granular catalyst with copper oxide and manganese dioxide as its main components, widely used for protection against carbon monoxide in fire-fighting filter-type self-rescue respirators, gas masks, and mine refuge chambers. Its protective principle is that under normal temperature and pressure conditions, the copper oxide and manganese dioxide in hogalat agent efficiently catalyze the conversion of carbon monoxide into carbon dioxide, achieving highly effective protection against carbon monoxide gas.

[0003] The main components of hogalat are manganese dioxide and copper oxide. Its manganese content is usually determined using Q / FX 8-127-2023, "Test Methods for Impregnated Activated Carbon: Determination of Cobalt, Nickel, Manganese, Cerium, Titanium, Potassium, and Sodium Content," but the measured manganese content is far lower than the theoretically calculated value.

[0004] Analysis of the reasons: Inductively coupled plasma atomic emission spectrometry (ICP-AES) utilizes the calibration curve of a standard solution and the proportional relationship between the concentration of the analyte and the emission intensity of the plasma spectral lines to achieve quantitative determination of the analyte. In solid samples, the analyte metal is extracted with acid, decomposed into metal ions, and then quantitatively analyzed using ICP-AES. However, when determining manganese using the Q / FX 8-127-2023 ICP-AES method, extraction with HNO3 at a volume ratio of 1:1 (approximately 8 mol / L concentration) is employed. HNO3 is acidic and a strong oxidizing agent, and its reaction with manganese dioxide in the hopalat reagent is as follows: 4HNO3 + MnO2 = Mn(NO3)2 + 2H2O + 2NO2 HNO3 + MnO2 = HMnO4 + NO As shown in the equation above, manganese dioxide reacts with HNO3 to produce Mn. 2+ MnO 4- Mn 2+ In a high-frequency electromagnetic field, manganese can lose electrons and undergo transitions, emitting characteristic spectral lines. The manganese content can be determined by utilizing the proportional relationship between the spectral line intensity and the manganese concentration. (MnO...) 4- In a high-frequency magnetic field, Mn does not undergo electronic transitions, therefore MnO 4- The manganese content in hopradiol cannot be determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Therefore, when HNO3 was used as the extraction solvent to extract manganese from hopradiol, the measured manganese content was much lower than the theoretically calculated value. The method Q / FX 8-127-2023 is not applicable to the determination of manganese content in hopradiol.

[0005] Because the manganese dioxide in the hogalat agent reacts with concentrated hydrochloric acid upon heating to produce Mn. 2+ The reaction equation is: MnO₂ + 4HCl (conc.) = MnCl₂ + 2H₂O + Cl₂ As mentioned above, manganese dioxide reacts with concentrated HCl to produce Mn. 2+ Therefore, concentrated hydrochloric acid can be used as the extraction solution for the determination of manganese in hogalate.

[0006] The content of copper oxide and manganese dioxide in hopalat directly affects its catalytic performance. The content of copper oxide and manganese dioxide can be calculated from the content of copper and manganese. Therefore, the method for determining the content of copper and manganese in hopalat is very important in the preparation and process research of hopalat. Summary of the Invention

[0007] This invention addresses the current lack of a method for determining the copper and manganese content in hopalat agents by providing a method for this purpose, thus offering technical guidance for hopalat agent preparation and process improvement.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: a method for determining the copper and manganese content in hopalat, comprising the following steps: 1) Prepare a series of copper standard solutions and a series of manganese standard solutions for calibration, respectively; 2) Take samples using the quartering method, grind them to obtain samples between 75 and 150 μm, place them in an electric thermostatic drying oven to dry, and then take them out and place them in a desiccator to cool for later use. 3) Weigh the dried sample to an accuracy of 0.0001 g, place it in an Erlenmeyer flask, add concentrated hydrochloric acid extract, and heat on a hot plate until it boils gently for 20 min. 4) Transfer the solution to a volumetric flask and dilute to volume with water, then mix well; 5) Filter the solution obtained in step 4) using a disposable syringe through a needle filter; 6) Accurately measure 5 mL of the solution obtained in step 5) and dilute it into a 50 mL volumetric flask, make up to volume, and mix well; 7) Set the working conditions of the plasma emission spectrometer, ignite the plasma torch, and after the instrument stabilizes, introduce the series of copper and manganese standard solutions for calibration prepared in step 1) into the plasma emission spectrometer in sequence to detect the spectral intensity of each element's analytical spectral line; perform linear regression with the net light intensity of each element as the dependent variable and the concentration of the element as the independent variable, plot the standard curve, and calculate the intercept and linear correlation. The linear correlation coefficient of the standard curve should not be less than 0.999. 8) Using a blank solution without the sample as a blank, measure the spectral intensity of copper in the solution obtained in step 5), measure the spectral intensity of manganese in the solution obtained in step 6), and calculate the concentrations of copper and manganese according to the standard curve.

[0009] As a further limitation of the technical solution of the present invention, in step 1), a series of copper standard solutions for calibration with a concentration of 100 μg / mL and a concentration of 50 μg / mL are prepared using a copper standard solution with a concentration of 1000 μg / mL; and a series of manganese standard solutions for calibration with a concentration of 50 μg / mL and a concentration of 20 μg / mL are prepared using a manganese standard solution with a concentration of 1000 μg / mL.

[0010] As a further limitation of the technical solution of the present invention, the drying temperature in the drying oven in step 2) is 105-110℃ and the drying time is 3h.

[0011] As a further limitation of the technical solution of the present invention, the mass-to-volume ratio of the dried sample to concentrated hydrochloric acid in step 3) is 0.1 g ± 0.0004 g: 30 mL.

[0012] As a further limitation of the technical solution of the present invention, the concentration of copper element is expressed as a mass fraction. w The values ​​are expressed as % and calculated according to formula (1): ……………………………………………(1) In the formula: w —Copper content, percentage%; c x —The concentration of copper in the sample solution obtained through the standard curve, in mg / L; c 0 —The concentration of copper in the blank solution obtained through the standard curve, in mg / L; V —The volume of the sample solution, in mL; m —The numerical value of the sample mass, in grams.

[0013] As a further limitation of the technical solution of the present invention, the concentration of manganese element is expressed as a mass fraction. w The values ​​are expressed as % and are calculated according to formula (2): ……………………………………………(2) In the formula: w —Manganese content, percentage% c x—The concentration of manganese in the sample solution obtained through the standard curve, in mg / L; c 0 —The concentration of manganese in the blank solution obtained through the standard curve, in mg / L; V —The volume of the sample solution, in mL; m —The numerical value of the sample mass, in grams.

[0014] As a further limitation of the technical solution of the present invention, the needle filter in step 5) is an aqueous filter membrane with a pore size of 0.45μm.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention is simple and convenient to operate, accurate and reliable, highly practical, and easy to implement. By determining the copper and manganese content in hogallat agent, the conversion rate of raw materials for hogallat agent preparation can be calculated, thus providing technical guidance for hogallat agent production and process improvement. Detailed Implementation

[0016] The present invention will be further described below with reference to specific embodiments. Example

[0017] A method for determining the copper and manganese content in hopalat, comprising the following steps: 1) Prepare a series of copper standard solutions for calibration using 100 μg / mL and 50 μg / mL copper standard solution; prepare a series of manganese standard solutions for calibration using 50 μg / mL and 20 μg / mL manganese standard solution using 1000 μg / mL manganese standard solution.

[0018] 2) Take about 10 g of sample using the quartering method, grind it to obtain a sample between 75 and 150 μm, place it in an electric thermostatic drying oven at 105 to 110 °C, dry it for 3 h, take it out and put it in a desiccator to cool for later use.

[0019] 3) Weigh 0.1 g ± 0.0004 g of the dried sample, accurate to 0.0001 g, place it in a 100 mL Erlenmeyer flask, add 30 mL of concentrated hydrochloric acid extract, and heat on a hot plate until it boils gently for 20 min.

[0020] 4) Transfer the solution to a 100 mL volumetric flask, wash the Erlenmeyer flask with water at least three times, transfer the washings to the volumetric flask, and after the solution has cooled to room temperature, dilute to volume with water and mix well.

[0021] 5) Take an appropriate amount of the solution obtained in step 4) and filter it through a needle filter (water-based filter membrane, pore size 0.45μm) into a stoppered triangular flask using a disposable syringe.

[0022] 6) Accurately measure 5 mL of the solution obtained in step 5) and dilute it into a 50 mL volumetric flask. Make up to volume and mix well.

[0023] 7) Set the operating conditions of the plasma atomic emission spectrometer, ignite the plasma torch, and after the instrument stabilizes, sequentially introduce the series of copper and manganese standard solutions prepared in step 1) into the plasma atomic emission spectrometer to detect the spectral intensity of each element's analytical lines. Perform linear regression with the net spectral intensity of each element as the dependent variable and the element's concentration as the independent variable, plot a standard curve, and calculate the intercept and linear correlation. The linear correlation coefficient of the standard curve should be no less than 0.999.

[0024] 8) Using a blank solution without the sample as a blank, determine the spectral intensity of copper in the solution obtained in 5) and the spectral intensity of manganese in the solution obtained in 6). Calculate the concentrations of copper and manganese based on the standard curve.

[0025] Result Calculation 1) Copper content The copper content is expressed as a mass fraction. w The values ​​are expressed as % and calculated according to formula (1): ……………………………………………(1) In the formula: w —Copper content, percentage (%); c x —The concentration of copper in the sample solution obtained through the standard curve, in milligrams per liter (mg / L). c 0 —The concentration of copper in the blank solution obtained through the standard curve, in milligrams per liter (mg / L). V —The volume of the sample solution, in milliliters (mL); m —The numerical value of the sample mass, in grams (g).

[0026] 2) Manganese content The content of manganese is expressed as a mass fraction. w The values ​​are expressed as % and are calculated according to formula (2): ……………………………………………(2) In the formula: w — Manganese content, percentage (%); c x —The concentration of manganese in the sample solution obtained through the standard curve, in milligrams per liter (mg / L). c 0 —The concentration of manganese in the blank solution obtained by the standard curve, in milligrams per liter (mg / L). V —The volume of the sample solution, in milliliters (mL); m —The numerical value of the sample mass, in grams (g).

[0027] Accuracy Each sample was measured twice in parallel. The difference between the two parallel measurements was: the copper content should not exceed 0.30%, and the manganese content should not exceed 2.00%. The results were expressed as the arithmetic mean, accurate to two decimal places.

[0028] The measurement principle of the method of this invention is as follows: The main components of hogalat are copper oxide and manganese dioxide. Copper oxide and manganese dioxide react with concentrated hydrochloric acid to produce Mn. 2+ and Cu 2+ Using plasma atomic emission spectrometry, Mn 2+ and Cu 2+ In a high-frequency electromagnetic field, the loss of electrons leads to transitions and the emission of characteristic spectral lines. The content of copper and manganese is determined by utilizing the proportional relationship between the intensity of these spectral lines and the element being measured. After acid decomposition and filtration into a solution, the sample is introduced into a plasma torch. Under the high temperature of the plasma, copper in the solution is excited and emits its characteristic spectral line (wavelength 324.754 nm), and manganese is excited and emits its characteristic spectral line (wavelength 260.569 nm). The content of copper and manganese can be determined by utilizing the proportional relationship between the spectral line intensity and the solution concentration. Since manganese dioxide does not react with dilute hydrochloric acid, concentrated hydrochloric acid must be used as the extraction solution. Because the manganese content in the hogallat agent is high, to avoid saturation of the manganese characteristic spectral line intensity during manganese content determination, the wavelength of the manganese characteristic spectral line at a relatively weak signal intensity of 260.569 nm is selected, and the solution must be diluted 10 times for measurement.

[0029] Samples of hopalat agent #1 to #8 were selected and tested using the method of this invention. The results are as follows: Table 1. Results of Copper and Manganese Content Determination in Hogalat Agent Samples

[0030] According to the determination method of the present invention, the hogalat agent sample is completely dissolved in the extract and the extraction is more thorough. The measured copper and manganese contents are consistent with the theoretical calculated values ​​of copper and manganese elements in the amount of hogalat agent raw material added. The determination results are more accurate and reliable, and can guide the production quality control and process technology improvement of hogalat agent products.

Claims

1. A method for determining the copper and manganese content in hopalat, characterized in that, Includes the following steps: 1) Prepare a series of copper standard solutions and a series of manganese standard solutions for calibration, respectively; 2) Take samples using the quartering method, grind them to obtain samples between 75 and 150 μm, place them in an electric thermostatic drying oven to dry, and then take them out and place them in a desiccator to cool for later use. 3) Weigh the dried sample to an accuracy of 0.0001 g, place it in an Erlenmeyer flask, add concentrated hydrochloric acid extract, and heat on a hot plate until it boils gently for 20 min. 4) Transfer the solution to a volumetric flask and dilute to volume with water, then mix well; 5) Filter the solution obtained in step 4) using a disposable syringe through a needle filter; 6) Accurately measure 5 mL of the solution obtained in step 5) and dilute it into a 50 mL volumetric flask, make up to volume, and mix well; 7) Set the working conditions of the plasma emission spectrometer, ignite the plasma torch, and after the instrument stabilizes, introduce the series of copper and manganese standard solutions for calibration prepared in step 1) into the plasma emission spectrometer in sequence to detect the spectral intensity of each element's analytical spectral line; perform linear regression with the net light intensity of each element as the dependent variable and the concentration of the element as the independent variable, plot the standard curve, and calculate the intercept and linear correlation. The linear correlation coefficient of the standard curve should not be less than 0.

999. 8) Using a blank solution without the sample as a blank, measure the spectral intensity of copper in the solution obtained in step 5), measure the spectral intensity of manganese in the solution obtained in step 6), and calculate the concentrations of copper and manganese according to the standard curve.

2. The method for determining the copper and manganese content in a hopalat agent according to claim 1, characterized in that, In step 1), a series of copper standard solutions for calibration, with concentrations of 100 μg / mL and 50 μg / mL, are prepared using a 1000 μg / mL copper standard solution; and a series of manganese standard solutions for calibration, with concentrations of 50 μg / mL and 20 μg / mL, are prepared using a 1000 μg / mL manganese standard solution.

3. The method for determining the copper and manganese content in a hopalat agent according to claim 1, characterized in that, Step 2) The drying temperature in the drying oven is 105-110℃, and the drying time is 3 hours.

4. The method for determining the copper and manganese content in a hopalat agent according to claim 1, characterized in that, In step 3), the mass-to-volume ratio of the dried sample to concentrated hydrochloric acid is 0.1 g ± 0.0004 g: 30 mL.

5. The method for determining the copper and manganese content in a hopalat agent according to claim 1, characterized in that, The concentration of copper is expressed as a mass fraction. w The values ​​are expressed as % and calculated according to formula (1): ……………………………………………（1） In the formula: w —Copper content, percentage%; c x —The concentration of copper in the sample solution obtained through the standard curve, in mg / L; c 0 —The concentration of copper in the blank solution obtained through the standard curve, in mg / L; V —The volume of the sample solution, in mL; m —The numerical value of the sample mass, in grams.

6. The method for determining the copper and manganese content in a hopalat agent according to claim 1, characterized in that, The concentration of manganese is expressed as a mass fraction. w The values ​​are expressed as % and are calculated according to formula (2): ……………………………………………（2） In the formula: w —Manganese content, percentage% c x —The concentration of manganese in the sample solution obtained through the standard curve, in mg / L; c 0 —The concentration of manganese in the blank solution obtained through the standard curve, in mg / L; V —The volume of the sample solution, in mL; m —The numerical value of the sample mass, in grams.

7. The method for determining the copper and manganese content in a hopalat agent according to claim 1, characterized in that, In step 5), the needle filter is an aqueous filter membrane with a pore size of 0.45 μm.

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