Chlorite schist medicinal material and content determination method of preparation thereof

Abstract

The invention provides a content determination method of a lapis chloriti medicinal material and a preparation thereof, aims at the content determination of the lapis chloriti medicinal material and decoction pieces, standard decoction and formula granules thereof, and can solve the problem that the technological process from the lapis chloriti medicinal material to a calcined lapis chloriti formula granule finished product is difficult to integrally evaluate and control in the prior art. According to the method, the blank in the prior art is filled up, the quality detection of the calcined lapis chloriti is comprehensive and reliable in production, meanwhile, the detection time is short, the detection method is stable, and large-scale application and popularization are facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of green malachite medicinal materials and preparation of content determination method, belong to the field of drug detection. BACKGROUND

[0002] Green malachite is metamorphic rock class biotite schist or chloritization mica carbonate schist. It is flat, sweet and salty, and has the effect of reducing phlegm, lowering qi, calming liver and calming. It is used for stubborn phlegm consolidation, coughing and wheezing, epilepsy, restlessness, chest tightness and convulsions.

[0003] Currently, there are few related literatures on the content determination of green malachite and its processed products. The main literature found is one. Liu Shengjin. Mineral medicine green malachite quality control technology research [D]. Nanjing University of Chinese Medicine, 2012. DOI: 10.7666 / d.y2124163. The literature mainly reports the quantitative research of iron, aluminum and calcium in medicinal materials, while green malachite mainly contains silicate components such as magnesium, iron and aluminum, and the content of silicon element is the highest. However, there is no literature reporting the content of silicon dioxide (SiO2) as the content index component. At the same time, the main detection method of iron, aluminum and calcium in the literature is titration method, which requires high sensitivity to discoloration. Combined with the fact that the main element in this variety is silicon, this method is difficult to reflect the transfer of components in green malachite from medicinal materials to granules in the process, and it is difficult to evaluate and control the whole process from green malachite medicinal materials to calcined green malachite decoction pieces, and then to calcined green malachite standard decoction and formula granules.

[0004] Currently, many existing technical methods are used in mineral medicines. For the main variety of green malachite, most of the researches are to identify green malachite by adopting characteristics, physicochemical, microscopic, thermal analysis and other technologies; or to conduct qualitative analysis by electron probe; and to analyze fingerprint or characteristic spectrum by infrared spectroscopy and ICP-MS. However, the quality index control of green malachite medicinal materials is currently reported only for the quantitative analysis of iron, aluminum and calcium. However, green malachite mainly contains silicate, and SIO2 is the main component of silicate, which accounts for a high proportion. Its content is closely related to the physical properties of medicinal materials such as hardness and adsorbability, and can directly indicate the purity of green malachite. Quantitative detection can effectively distinguish the authenticity of medicinal materials (green malachite and counterfeit products, with large difference in SIO2 content), and ensure the authenticity of raw materials. At the same time, SIO2 in green malachite plays a supporting role as a basic substance in the process of liver calming and calming, and cooperates with other components to produce effects. Because SIO2 exists in the form of silicate in green malachite, it is chemically stable and not easily affected by processing, storage and other processes, and is more likely to truly reflect the quality of medicinal materials and stably transfer in each process. Therefore, SIO2 is an ideal content index of green malachite due to its high content and high stability, but this content index is not controlled in the quality standards related to green malachite. SUMMARY

[0005] This invention provides a method for determining the content of chlorite medicinal materials and their preparations.

[0006] This invention provides a method for determining the content of chlorite medicinal material and its preparations, which includes the following steps:

[0007] a. Melting: Take Qingmengshi medicinal materials and their preparations, add potassium hydroxide, and melt them in a high-temperature furnace;

[0008] b. Leaching and acidification: Leach the molten metal from step a with boiling water; add hydrochloric acid and nitric acid sequentially to the leaching solution while stirring, and then cool.

[0009] c. Precipitation: Add potassium chloride until the test solution is saturated, then slowly add potassium fluoride solution, stir, let stand, and a precipitate will form;

[0010] d. Filtration and washing: Filtration, washing with potassium chloride-ethanol solution, and precipitation;

[0011] e. Acid washing and neutralization: Transfer the precipitate and filter paper back to the beaker, crush the filter paper, add washing solution and phenolphthalein indicator, and titrate the residual acid with NaOH until it turns slightly red.

[0012] f. Titration: After keeping warm in a water bath, add boiling water and immediately titrate with NaOH using a potentiometric titrator to the endpoint, then calculate the SiO2 content.

[0013] The melting time in step a is 30 minutes; the mass ratio of chlorite to potassium hydroxide in step a is 0.1:6; and the melting temperature is 600–650℃.

[0014] In step b, hydrochloric acid is added to the extract under stirring until it becomes clear, then nitric acid is added and the mixture is cooled. For every 0.1g of Qingmengshi medicinal material and its preparations, 15ml of hydrochloric acid and 10ml of nitric acid are added.

[0015] In step c, the concentration of the potassium fluoride solution is 300 g / L, and the stirring time is 2 min; the settling temperature in step c is 15℃~25℃, and the time is 30 min.

[0016] In step d, the concentration of sodium chloride in the potassium chloride-ethanol solution is 50 g / L; the volume ratio of water to anhydrous ethanol is 1:1; the washing frequency in step d is 3 times, and the precipitation frequency is 8 times.

[0017] In step e, the washing solution is a potassium chloride solution with a concentration of 50 g / L, and the dosage is 20 ml of potassium chloride per 0.1 g of chlorite, with a water:anhydrous ethanol volume ratio of 1:1; the concentration of the phenolphthalein ethanol solution is 10 g / L.

[0018] In step f, the water bath temperature is 80℃, the water bath is kept warm for 3–5 minutes, the concentration of NaOH is 0.1mol / L, and the amount of boiling water used is 150ml of boiling water per 0.1g of chlorite.

[0019] The formula for calculating the SiO2 content in step f is as follows:

[0020]

[0021] In the formula: C — the concentration of the sodium hydroxide standard titration solution, in moles per liter (mol / L);

[0022] V—The volume of sodium hydroxide standard titration solution consumed during titration of the test solution, in milliliters (ml);

[0023] V1—The volume of sodium hydroxide standard titration solution consumed when titrating the blank solution, in milliliters (ml);

[0024] M1—Molar mass of silicon dioxide, 60.0, in grams per mole (g / mol);

[0025] m1 — Mass of the sample, in grams (g);

[0026] After the reaction of 4-1 / 4 mol of silicon dioxide, the titration consumes 1 mol of sodium hydroxide.

[0027] The aforementioned chlorite medicinal materials and their preparations include chlorite medicinal materials, calcined chlorite slices, calcined chlorite standard decoction, and calcined chlorite formula granules.

[0028] The silica content in the chlorite medicinal material is 39.9-53.1%; the silica content in the calcined chlorite slices is 46.7-55.3%; the silica content in the calcined chlorite standard decoction is 353.2-469.7 mg / g; and the silica content in the calcined chlorite granules is 49.5-51.0 mg / g.

[0029] Potassium fluorosilicate volumetric titration is a traditional classical titration method, but its difficulty lies in the fact that endpoint determination heavily relies on the operator's experience, making it highly subjective. During the research process, the inventors repeatedly attempted to test the same sample, but the measured error range was large, resulting in low accuracy. To address this challenge and ensure the accuracy of the results, we adopted the principle of potassium fluorosilicate volumetric titration, combining it with a potentiometric titrator to determine the titration endpoint. This improved approach not only avoids interference from solution color and turbidity but also eliminates subjective errors caused by differences in operator experience, thereby reducing the risk of errors from visual judgment and making the results more accurate and objective.

[0030] This invention provides a method for determining the content of calcined chlorite medicinal materials and their processed slices, standard decoctions, and formulation granules. This method can solve the problem of difficulty in comprehensively evaluating and controlling the process from calcined chlorite medicinal materials to calcined chlorite formulation granules in the existing technology, thereby filling the gap in the existing technology. It provides comprehensive and reliable quality testing of calcined chlorite in production, while also having a short testing time and a relatively stable testing method, which is convenient for large-scale promotion and application. Attached Figure Description

[0031] Figure 1 Linear relationship of silicon dioxide;

[0032] Figure 2 Linear relationship of silicon dioxide;

[0033] Figure 3 Linear relationship of silicon dioxide. Detailed Implementation

[0034] Example 1: Method for determining the content of chlorite medicinal materials and calcined chlorite slices

[0035] Accurately weigh approximately 0.1 g of the fine powder and place it in a 100 ml nickel crucible containing 6 g of potassium hydroxide. Mix well. Melt in a furnace at 600℃~650℃ for 30 min, then remove and cool slightly. Pour small amounts of boiling water into a 300 ml polyethylene beaker, washing the crucible with water, ensuring the volume does not exceed 50 ml. While stirring continuously, add 15 ml of hydrochloric acid and stir until clear. Add 10 ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5 ml of potassium fluoride solution (300 g / L) while stirring, stirring for 2 min. Precipitate at 15℃~25℃ and let stand for 30 min. Filter using rapid filter paper and a plastic funnel. Wash the beaker 3 times and the precipitate 8 times with potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1). Place the precipitate and filter paper into a beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath at above 80°C for 3–5 minutes, remove, and immediately add 150 ml of boiling water. Using a potentiometric titrator, immediately titrate with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint.

[0036] Calculation formula:

[0037] In the formula: C — the concentration of the sodium hydroxide standard titration solution, in moles per liter (mol / L);

[0038] V—The volume of sodium hydroxide standard titration solution consumed during titration of the test solution, in milliliters (ml);

[0039] V1—The volume of sodium hydroxide standard titration solution consumed when titrating the blank solution, in milliliters (ml);

[0040] M1—Molar mass of silicon dioxide, 60.0, in grams per mole (g / mol);

[0041] m1 — Mass of the sample, in grams (g);

[0042] After the reaction of 4-1 / 4 mol of silicon dioxide, the titration consumes 1 mol of sodium hydroxide.

[0043] Example 2: Method for determining the content of calcined chlorite in standard decoction

[0044] Accurately weigh approximately 0.1 g of the powder and place it in a 100 ml nickel crucible containing 6 g of potassium hydroxide. Mix well. Melt in a furnace at 600℃~650℃ for 30 min, then remove and cool slightly. Pour small amounts of boiling water into a 300 ml polyethylene beaker, washing the crucible with water, ensuring the volume does not exceed 50 ml. While stirring continuously, add 15 ml of hydrochloric acid and stir until clear. Add 10 ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5 ml of potassium fluoride solution (300 g / L) while stirring, stirring for 2 min. Precipitate at 15℃~25℃ and let stand for 30 min. Filter using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper into a beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath at above 80°C for 3–5 minutes, remove, and immediately add 150 ml of boiling water. Using a potentiometric titrator, immediately titrate with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint.

[0045] Calculation formula:

[0046] In the formula: C — the concentration of the sodium hydroxide standard titration solution, in moles per liter (mol / L);

[0047] V—The volume of sodium hydroxide standard titration solution consumed during titration of the test solution, in milliliters (ml);

[0048] V1—The volume of sodium hydroxide standard titration solution consumed when titrating the blank solution, in milliliters (ml);

[0049] M1—Molar mass of silicon dioxide, 60.0, in grams per mole (g / mol);

[0050] m1 — Mass of the sample, in grams (g);

[0051] After the reaction of 4-1 / 4 mol of silicon dioxide, the titration consumes 1 mol of sodium hydroxide.

[0052] Example 3: Method for Determination of Particle Content in Calcined Green Lapis Lazuli Formulation

[0053] Take an appropriate amount of this product, grind it into a fine powder, and accurately weigh about 0.5g. Place the powder in a 100ml nickel crucible containing 6g of potassium hydroxide and mix well. Melt the crucible in a high-temperature furnace at 600℃~650℃ for 30min, then remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, wash the crucible with water, and control the volume to not exceed 50ml. Add 15ml of hydrochloric acid while stirring continuously until the solution is clear. Add 10ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stir for 2min, and precipitate at 15℃~25℃ for 30min. Filter using rapid filter paper and a plastic funnel, wash the beaker 3 times with potassium chloride solution (50g / L; water: anhydrous ethanol 1:1), and precipitate 8 times. Place the precipitate and filter paper into a beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath at above 80°C for 3–5 minutes, remove, and immediately add 150 ml of boiling water. Using a potentiometric titrator, immediately titrate with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint.

[0054] Calculation formula:

[0055] In the formula: C — the concentration of the sodium hydroxide standard titration solution, in moles per liter (mol / L);

[0056] V—The volume of sodium hydroxide standard titration solution consumed during titration of the test solution, in milliliters (ml);

[0057] V1—The volume of sodium hydroxide standard titration solution consumed when titrating the blank solution, in milliliters (ml);

[0058] M1—Molar mass of silicon dioxide, 60.0, in grams per mole (g / mol);

[0059] m1 — Mass of the sample, in grams (g);

[0060] After the reaction of 4-1 / 4 mol of silicon dioxide, the titration consumes 1 mol of sodium hydroxide.

[0061] Example 4: Establishment of a method for determining the content of chlorite in medicinal materials

[0062] 1. Experimental instruments and materials

[0063] Electronic balances: ME204E / 02, MS205DM, XP26 (Mettler-Toledo Instruments Ltd.);

[0064] Ultrapure water system: Cellular type 1810A (Shanghai Moler Scientific Instruments Co., Ltd.);

[0065] Ultrasonic cleaner: KQ-600DB model (600W, 40KHz; Kunshan Ultrasonic Instrument Co., Ltd.);

[0066] Box-type electric furnace: SX2 (manufactured by Shanghai Pudong Rongfeng Scientific Instruments Co., Ltd. and Shanghai Shengxin Scientific Instruments Co., Ltd.);

[0067] Potentiometric titrator: G10S (Mettler-Toledo Instruments Ltd.);

[0068] 50ml burette; 30ml nickel crucible; 100ml nickel crucible; 300ml plastic beaker, etc.

[0069] Potassium hydroxide, hydrochloric acid, nitric acid, potassium chloride, potassium fluoride, anhydrous ethanol, phenolphthalein, sodium hydroxide, silicon dioxide, and other reagents were all of analytical grade. Potassium hydrogen phthalate was used as a primary standard, and the water was ultrapure water.

[0070] Green stone medicinal materials (batch number: YC-QMS-01, YC-QMS-02, YC-QMS-03, YC-QMS-04, YC-QMS-05, YC-QMS-06, YC-QMS-07, YC-QMS-08, YC-QMS-09, YC-QMS-10, YC-QMS-11, YC-QMS-12, YC-QMS-13, YC-QMS-14, YC-QMS-15, YC-QMS-16, YC-QMS-17, YC-QMS-18, YC-QMS-19, YC-QMS-20, YC-QMS-21)

[0071] Forged green stone pieces (batch number: YP-DQMS-01, YP-DQMS-02, YP-DQMS-03, YP-DQMS-04, YP-DQMS-05, YP-DQMS-06, YP-DQMS-07, YP-DQMS-08, YP-DQMS-09, YP-DQMS-10, YP-DQMS-11, YP-DQMS-12, YP-DQMS-13, YP-DQMS-14, YP-DQMS-15, YP-DQMS-16, YP-DQMS-17, YP-DQMS-18, YP-DQMS-19, YP-DQMS-20, YP-DQMS-21)

[0072] 2. Optimization of test solution preparation and determination methods

[0073] 2.1 Sample Size Assessment

[0074] Take two portions each of the fine powder of this product (batch number: YC-QMS-21) of 0.1g, 0.2g, and 0.3g, for a total of six portions. Accurately weigh each portion and place them in a 100ml nickel crucible containing 4g of potassium hydroxide, and mix well. Melt the crucible in a high-temperature furnace at 600℃~650℃ for 15min, then remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, and wash the crucible with water, controlling the volume to not exceed 50ml. While stirring continuously, add 15ml of hydrochloric acid and stir until clear. Add 10ml of nitric acid and cool. Add 3g of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, and stir for 2min. Precipitate at 15℃~25℃ and let stand for 30min. Filter the solution using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper back into the beaker, crush the filter paper, add 10 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate any remaining acid with a standard sodium hydroxide solution (0.1 mol / L), squeezing the filter paper and precipitate until the solution just turns red and does not fade (ignoring the volume of the standard sodium hydroxide solution). Add 100 ml of boiling water and titrate immediately with a standard sodium hydroxide solution (0.1 mol / L) to the endpoint using a potentiometric titrator. Analyze and calculate the silica content under different sample amounts; the results are shown in Table 1.

[0075] Table 1 Sampling Quantity Investigation

[0076]

[0077] The results showed that the highest content was found at a sample size of 0.1g, and the titration volume consumed was relatively large at 0.2g and 0.3g. Therefore, considering all factors, a sample size of 0.1g was more appropriate.

[0078] 2.2 Investigation on the amount of potassium hydroxide added

[0079] Take 0.1g of the fine powder (batch number: YC-QMS-21), making six portions. Accurately weigh each portion and place them in separate 100ml nickel crucibles containing 3g, 4g, and 6g of potassium hydroxide, respectively, and mix well. Melt the crucibles in a high-temperature furnace at 600℃~650℃ for 15min, then remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, washing the crucible with water, ensuring the volume does not exceed 50ml. While stirring continuously, add 15ml of hydrochloric acid and stir until clear. Add 10ml of nitric acid and cool. Add 3g of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stirring for 2min. Precipitate at 15℃~25℃ and let stand for 30min. Filter using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper in a beaker, crush the filter paper, add 10 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Add 100 ml of boiling water and titrate immediately with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint using a potentiometric titrator. Analyze and calculate the silica content under different amounts of potassium hydroxide added; the results are shown in Table 2.

[0080] Table 2. Investigation of potassium hydroxide addition amount

[0081]

[0082]

[0083] The results showed that there was no significant difference in the content of potassium hydroxide with the addition of 4g and 6g. In order to ensure complete melting of the sample and facilitate the subsequent elution of the melt, thereby ensuring the accuracy of the determination, the amount of potassium hydroxide added was selected as 6g.

[0084] 2.3 Melting Time Investigation

[0085] Take 0.1g of the fine powder of this product (batch number: YC-QMS-21), making six portions. Accurately weigh each portion and place them in a 100ml nickel crucible containing 6g of potassium hydroxide, and mix well. Place them in a high-temperature furnace at 600℃~650℃ and melt for 15min, 30min, and 45min respectively, then remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, wash the crucible with water, and control the volume to not exceed 50ml. While stirring constantly, add 15ml of hydrochloric acid and stir until clear. Add 10ml of nitric acid and cool. Add 3g of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stir for 2min, and precipitate at 15℃~25℃ for 30min. Filter using rapid filter paper and a plastic funnel, wash the beaker three times with potassium chloride solution (50g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper in a beaker, crush the filter paper, add 10 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Add 100 ml of boiling water and titrate immediately with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint using a potentiometric titrator. Analyze and calculate the silica content at different melting times; the results are shown in Table 3.

[0086] Table 3. Melting Time Investigation

[0087]

[0088] The results showed that there was no significant difference in the final content between melting for 15 minutes and melting for 30 minutes and 45 minutes, but in order to ensure complete melting of the sample, the final melting time was 30 minutes.

[0089] 2.4 Investigation of Acid Addition Amount

[0090] After the molten material is leached with hot water, it needs to be acidified promptly to ensure that all compounds in the molten sample exist in ionic form in the acidic solution. Acidity is a crucial factor affecting the complete precipitation of potassium fluorosilicate; excessively high acidity increases the solubility and decomposition of the precipitate, while excessively low acidity easily leads to the formation of other fluoride salts, interfering with the determination. Therefore, the amount of acid added to the solution needs to be carefully considered.

[0091] Take 0.1g of the fine powder (batch number: YC-QMS-21), four times in total. Accurately weigh each portion and place them in a 100ml nickel crucible containing 6g of potassium hydroxide, then mix well. Place the crucibles in a high-temperature furnace at 600℃~650℃ and melt for 30min. Remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, washing the crucibles with water, ensuring the volume does not exceed 50ml. While stirring continuously, add 15ml and 20ml of hydrochloric acid respectively, stirring until clear. Then add 10ml and 20ml of nitric acid respectively, and cool. Add 3g of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stirring for 2min. Precipitate at 15℃~25℃ and let stand for 30min. Filter the solution using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper back into the beaker, crush the filter paper, add 10 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Add 100 ml of boiling water and titrate immediately with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint using a potentiometric titrator. Analyze and calculate the silica content under different acid addition amounts; the results are shown in Table 4.

[0092] Table 4. Investigation of different acid addition amounts

[0093]

[0094] The results showed that 15 ml of hydrochloric acid and 10 ml of nitric acid were sufficient, so the amount of acid added in the standard method was not changed.

[0095] 2.5 Determination of the amount of potassium chloride added

[0096] Potassium chloride is readily soluble in water. In this method, the amount of potassium chloride added is related to the amount of boiling water used for washing. The more water used to wash the molten block and crucible, the more potassium chloride will be required when adding it and stirring until the test solution is saturated and a small amount of potassium chloride remains undissolved. Therefore, to ensure the stability of this method, it is more appropriate to change "add 3g of potassium chloride and stir until the test solution is saturated and a small amount of potassium chloride remains undissolved" to "add an appropriate amount of potassium chloride and stir until the test solution is saturated and a small amount of potassium chloride remains undissolved".

[0097] 2.6 Determination of the amount of potassium fluoride added

[0098] The principle of the potassium fluorosilicate titration method for determining SiO2 is to decompose the sample under high temperature and strong alkaline conditions, converting insoluble SiO2 into soluble silicates. These soluble silicates react with excess fluoride and potassium ions in a strongly acidic solution to form potassium fluorosilicate precipitate. This precipitate hydrolyzes in hot water to form hydrofluoric acid, which is then titrated with a standard sodium hydroxide solution. The SiO2 content in the sample is calculated based on the amount of sodium hydroxide consumed in the titration. The reaction equation is as follows:

[0099] SiO2+6KF+4HCl→K2SiF6+4KCl+2H2O;

[0100] K2SiF6+3H2O→4HF+H2SiO3+2KF;

[0101] HF + NaOH → H₂O + NaF;

[0102] As shown in the above formula, 1 mol of SiO2 requires 6 mol of KF for precipitation. The amount of 300 g / L KF added is 5 ml, which is 0.02582 mol. The precipitable SiO2 is 0.004303 mol, equivalent to approximately 258 mg. However, based on the results of the above investigation regarding sampling amount and potassium hydroxide addition, the SiO2 content in 0.1 g of chlorite (biotite schist) medicinal material is approximately 50 mg. The amount of precipitable SiO2 is far greater than the SiO2 content in 0.1 g of chlorite (biotite schist) medicinal material. In conclusion, the amount of KF added in this method is sufficient; therefore, the amount of KF used in this method will not be further investigated.

[0103] 2.7 Sedimentation Time Examination

[0104] Take 0.1g of the fine powder (batch number: YC-QMS-21), four times in total. Accurately weigh each portion and place them in a 100ml nickel crucible containing 6g of potassium hydroxide, then mix well. Place the crucible in a high-temperature furnace at 600℃~650℃ and melt for 30min. Remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, washing the crucible with water, ensuring the volume does not exceed 50ml. While stirring continuously, add 15ml of hydrochloric acid and stir until clear. Add 10ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stirring for 2min. Precipitate at 15℃~25℃ and allow to stand for 30min and 60min respectively. Filter using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper in a beaker, crush the filter paper, add 10 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Add 100 ml of boiling water and titrate immediately with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint using a potentiometric titrator. Analyze and calculate the silica content at different precipitation times; the results are shown in Table 5.

[0105] Table 5. Investigation of sedimentation time

[0106]

[0107] The results showed that the content difference between 30 minutes and 60 minutes of precipitation was not significant, indicating that precipitation was basically complete after 30 minutes. Therefore, considering factors such as saving time and cost, the final precipitation time was 30 minutes.

[0108] 2.8 Investigation into the amount of potassium chloride solution added before the first titration

[0109] Take 0.1g of the fine powder (batch number: YC-QMS-21), making eight portions. Accurately weigh each portion and place them in a 100ml nickel crucible containing 6g of potassium hydroxide, then mix well. Melt the crucible in a high-temperature furnace at 600℃~650℃ for 30min, then remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, washing the crucible with water, ensuring the volume does not exceed 50ml. While stirring continuously, add 15ml of hydrochloric acid and stir until clear. Add 10ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stirring for 2min. Precipitate at 15℃~25℃ and let stand for 30min. Filter using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper into a beaker, crush the filter paper, and add 10 ml, 20 ml, 30 ml, and 40 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L), respectively. Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Add 100 ml of boiling water and titrate immediately with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint using a potentiometric titrator. Analyze and calculate the silica content under different amounts of potassium chloride solution added before the first titration; the results are shown in Table 6.

[0110] Table 6. Investigation of the amount of potassium chloride solution added.

[0111]

[0112]

[0113] The results showed that the content did not change significantly with the increase of potassium chloride solution added. However, because too little potassium chloride solution was added, the first titration was unevenly stirred, which could easily increase the titration endpoint error. Therefore, after comprehensive consideration, the amount of potassium chloride solution added was selected to be 20 ml.

[0114] 2.9 Whether to keep the water warm before adding boiling water

[0115] Take 0.1g of the fine powder (batch number: YC-QMS-21), four times in total. Accurately weigh each portion and place them in a 100ml nickel crucible containing 6g of potassium hydroxide, then mix well. Melt the crucibles in a high-temperature furnace at 600℃~650℃ for 30min, then remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, washing the crucibles with water, ensuring the volume does not exceed 50ml. While stirring continuously, add 15ml of hydrochloric acid and stir until clear. Add 10ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stirring for 2min. Precipitate at 15℃~25℃ and let stand for 30min. Filter using rapid filter paper and a plastic funnel, wash the beakers three times with potassium chloride solution (50g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper in a beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate two portions in a water bath above 80℃ for 3-5 minutes, and do not incubate the other two portions. Add 100 ml of boiling water to each portion and titrate immediately with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint using a potentiometric titrator. Analyze and calculate the silica content before adding boiling water and without incubation. The results are shown in Table 7.

[0116] Table 7: Inquiry into whether boiling water was kept warm before being added.

[0117]

[0118] The results showed that whether or not the sample was kept warm after the first titration did not significantly affect the content. Based on the literature description that "the hydrolysis of potassium fluorosilicate is an endothermic reaction, requiring a large volume and high temperature for complete hydrolysis of the precipitate, and the hydrolysis reaction continues until it reaches the titration endpoint, thus requiring a titration endpoint temperature of no less than 60℃," it was decided to keep the sample warm after the first titration to ensure complete hydrolysis of the precipitate. The volume of boiling water added during hydrolysis was also investigated.

[0119] 2.10 Investigation of the volume of boiling water added

[0120] Take 0.1g of the fine powder (batch number: YC-QMS-21), making six portions. Accurately weigh each portion and place them in a 100ml nickel crucible containing 6g of potassium hydroxide, then mix well. Melt the crucible in a high-temperature furnace at 600℃~650℃ for 30min, then remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, washing the crucible with water, ensuring the volume does not exceed 50ml. While stirring continuously, add 15ml of hydrochloric acid and stir until clear. Add 10ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stirring for 2min. Precipitate at 15℃~25℃ and let stand for 30min. Filter using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper in a beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath at above 80℃ for 3-5 minutes, remove, and immediately add 100 ml, 150 ml, and 200 ml of boiling water respectively. Use a potentiometric titrator and immediately titrate with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint. Analyze and calculate the silica content under different amounts of boiling water added; the results are shown in Table 8.

[0121] Table 8. Investigation of Boiling Water Addition Amount

[0122]

[0123] The results showed that the three different amounts of boiling water added had little effect on the content results. To ensure complete hydrolysis of the precipitate and to prevent liquid splashing during titration due to excessive sample volume, a boiling water addition of 150 ml was selected.

[0124] In summary, the method for determining the silicon dioxide (SiO2) content in the medicinal material *Qingmengshi* (biotite schist) is as follows: Accurately weigh approximately 0.1 g of the fine powder and place it in a 100 ml nickel crucible containing 6 g of potassium hydroxide, mixing thoroughly. Melt the crucible in a furnace at 600℃~650℃ for 30 min, then remove and allow to cool slightly. Pour small amounts of boiling water into a 300 ml polyethylene beaker multiple times, rinsing the crucible with water, ensuring the volume does not exceed 50 ml. While continuously stirring, add 15 ml of hydrochloric acid and stir until clear. Add 10 ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5 ml of potassium fluoride solution (300 g / L) while stirring, stirring for 2 min. Precipitate at 15℃~25℃ and allow to stand for 30 min. Filter using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper back into the beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the remaining acid with standard sodium hydroxide solution (0.1 mol / L), squeezing the filter paper and precipitate until the solution just turns red and does not fade (ignoring the volume of the standard sodium hydroxide solution). Incubate in a water bath above 80°C for 3–5 minutes, remove, and immediately add 150 ml of boiling water. Titrate with standard sodium hydroxide solution (0.1 mol / L) to the endpoint using a potentiometric titrator.

[0125] 3. Methodological Examination

[0126] 3.1 Specificity test

[0127] The test solution and blank solution were prepared according to the proposed test sample preparation method, and the results were measured according to the proposed method. The results are shown in Table 9 below.

[0128] Table 9 Results of Specificity Analysis

[0129]

[0130] The results show that the method has good specificity and can determine the content of chlorite (biotite schist) medicinal materials without interference from blank samples.

[0131] 3.2 Repeatability Test

[0132] Take approximately 0.1 g of the fine powder of this product (batch number: YC-QMS-21), accurately weigh 6 portions, and have the same operator prepare the test solution according to the proposed method and determine the content of silicon dioxide in the 6 test samples. The results are shown in Table 10.

[0133] Table 10 Results of Repeatability Analysis

[0134]

[0135] The results showed that the RSD value of the silica (SiO2) content obtained from the six repeatability tests was 0.6%, indicating that the method had good repeatability.

[0136] 3.3 Accuracy Assessment

[0137] Take approximately 0.05 g of the test sample (batch number: YC-QMS-21, with a silica content (SiO2) of 44.7%), in six portions. Accurately weigh each portion and add an appropriate amount of silica (SiO2) to each sample. The purity is assumed to be 99.0%. Prepare and determine the test sample solution according to the proposed method, and calculate the recovery rate.

[0138] The results are shown in Table 11, and the calculation formula is as follows:

[0139]

[0140] Table 11 Accuracy Evaluation Results

[0141]

[0142] The results showed that the average recovery rate of silica was 99.5%, indicating that the method has good accuracy.

[0143] 3.4 Intermediate Precision Examination

[0144] The same test sample (batch number: YC-QMS-21) was used, and different personnel (A, B) prepared the test sample solution at different times (I, II) for analysis. The silica content in the test sample was calculated, and the results are shown in Table 12.

[0145] Table 12 Results of intermediate precision test

[0146]

[0147] The results show that the RSD value for intermediate precision testing of silica content is 1.4%, indicating good intermediate precision of this method.

[0148] 3.5 Linear Relationship

[0149] Accurately weigh 3 mg, 6 mg, 12 mg, 24 mg, 96 mg, and 192 mg of silicon dioxide, respectively, and place them in 100 ml nickel crucibles containing 6 g of potassium hydroxide, then mix well. Melt the crucibles in a furnace at 600℃~650℃ for 30 min, then remove and let cool slightly. Pour small amounts of boiling water into a 300 ml polyethylene beaker, rinsing the crucible with water, ensuring the volume does not exceed 50 ml. While stirring continuously, add 15 ml of hydrochloric acid and stir until clear. Add 10 ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5 ml of potassium fluoride solution (300 g / L) while stirring, stirring for 2 min. Precipitate at 15℃~25℃ and let stand for 30 min. Filter using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper in a beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath at 80℃ or above for 3-5 minutes, remove, and immediately add 150 ml of boiling water. Using a potentiometric titrator, immediately titrate with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint. Record the volume of titrant consumed. Plot a curve with the amount of silica sampled (X, mg) on ​​the x-axis and the volume of titrant consumed (Y, ml) on the y-axis. The results are shown in Table 13. Figure 1 .

[0150] Table 13 Results of the linearity test

[0151]

[0152] The results showed that the linear relationship between the sample amount of silica and the titration volume was y = 1.0729x - 4.2491, with an R² value of 0.9991, indicating that silica exhibited a good linear relationship in the range of 3.97 mg to 192.351 mg.

[0153] 3.6 Verification of the content determination of medicinal materials in chlorite (biotite schist)

[0154] The content of medicinal materials from 21 batches of chlorite (biotite schist) was determined, and the results are shown in Table 14.

[0155] Table 14 Results of the determination of medicinal content in chlorite (biotite schist).

[0156]

[0157]

[0158] 3.7 Verification of the content determination of calcined chlorite (biotite schist) slices

[0159] The content of calcined chlorite (biotite schist) slices in 21 batches was determined using the above method, and the results are shown in Table 15.

[0160] Table 15 Results of content determination of calcined chlorite (biotite schist) in medicinal slices

[0161]

[0162]

[0163] 4. Determination of the content of chlorite medicinal materials and calcined chlorite decoction pieces

[0164] Accurately weigh approximately 0.1 g of the fine powder and place it in a 100 ml nickel crucible containing 6 g of potassium hydroxide. Mix well. Melt in a furnace at 600℃~650℃ for 30 min, then remove and cool slightly. Pour small amounts of boiling water into a 300 ml polyethylene beaker, washing the crucible with water, ensuring the volume does not exceed 50 ml. While stirring continuously, add 15 ml of hydrochloric acid and stir until clear. Add 10 ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5 ml of potassium fluoride solution (300 g / L) while stirring, stirring for 2 min. Precipitate at 15℃~25℃ and let stand for 30 min. Filter using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper into a beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath at above 80°C for 3–5 minutes, remove, and immediately add 150 ml of boiling water. Titrate to the endpoint using a potentiometric titrator with sodium hydroxide standard titration solution (0.1 mol / L).

[0165] Calculation formula:

[0166] In the formula: C — the concentration of the sodium hydroxide standard titration solution, in moles per liter (mol / L);

[0167] V—The volume of sodium hydroxide standard titration solution consumed during titration of the test solution, in milliliters (ml);

[0168] V1—The volume of sodium hydroxide standard titration solution consumed when titrating the blank solution, in milliliters (ml);

[0169] M1—Molar mass of silicon dioxide, 60.0, in grams per mole (g / mol);

[0170] m1 — Mass of the sample, in grams (g);

[0171] After the reaction of 4-1 / 4 mol of silicon dioxide, the titration consumes 1 mol of sodium hydroxide.

[0172] Example 5: Establishment of a method for determining the content of calcined chlorite in a standard decoction.

[0173] 1. Reagents and Instruments

[0174] Electronic balances: ME204E / 02, MS205DM, XP26 (Mettler-Toledo Instruments Ltd.);

[0175] Ultrapure water system: Cellular type 1810A (Shanghai Moler Scientific Instruments Co., Ltd.);

[0176] Ultrasonic cleaner: KQ-600DB model (600W, 40KHz; Kunshan Ultrasonic Instrument Co., Ltd.);

[0177] Box-type electric furnace: SX2 (manufactured by Shanghai Pudong Rongfeng Scientific Instruments Co., Ltd. and Shanghai Shengxin Scientific Instruments Co., Ltd.);

[0178] Potentiometric titrator: G10S (Mettler-Toledo Instruments Ltd.);

[0179] 50ml burette; 30ml nickel crucible; 100ml nickel crucible; 300ml plastic beaker, etc.

[0180] Potassium hydroxide, hydrochloric acid, nitric acid, potassium chloride, potassium fluoride, anhydrous ethanol, phenolphthalein, sodium hydroxide, silicon dioxide, and other reagents were all of analytical grade. Potassium hydrogen phthalate was used as a primary standard, and the water was ultrapure water.

[0181] Calcined green stone standard decoction (batch number: BT-DQMS-01, BT-DQMS-02, BT-DQMS-03, BT-DQMS-04, BT-DQMS-05, BT-DQMS-06, BT-DQMS-07, BT-DQMS-08, BT-DQMS-09, BT-DQMS-10 , BT-DQMS-11, BT-DQMS-12, BT-DQMS-13, BT-DQMS-14, BT-DQMS-15, BT-DQMS-16, BT-DQMS-17, BT-DQMS-18, BT-DQMS-19, BT-DQMS-20, BT-DQMS-21)

[0182] 2. Determine the experimental conditions

[0183] The content of biotite (biotite schist) in medicinal materials and calcined biotite (biotite schist) processed slices was tested using the following specific methods:

[0184] Accurately weigh approximately 0.1 g of the powder and place it in a 100 ml nickel crucible containing 6 g of potassium hydroxide. Mix well. Melt in a furnace at 600℃~650℃ for 30 min, then remove and cool slightly. Pour small amounts of boiling water into a 300 ml polyethylene beaker, washing the crucible with water, ensuring the volume does not exceed 50 ml. While stirring continuously, add 15 ml of hydrochloric acid and stir until clear. Add 10 ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5 ml of potassium fluoride solution (300 g / L) while stirring, stirring for 2 min. Precipitate at 15℃~25℃ and let stand for 30 min. Filter using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper into a beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath at above 80°C for 3–5 minutes, remove, and immediately add 150 ml of boiling water. Using a potentiometric titrator, immediately titrate with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint.

[0185] 3. Preparation and Investigation of Test Samples

[0186] 3.1 Sample Quantity Assessment

[0187] Take two portions each of the powder (batch number: BT-DQMS-21) of this product (0.1g, 0.2g, and 0.3g), for a total of six portions. Accurately weigh each portion and place them in a 100ml nickel crucible containing 6g of potassium hydroxide, and mix well. Melt the crucible in a high-temperature furnace at 600℃~650℃ for 30 minutes, then remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, washing the crucible with water, ensuring the volume does not exceed 50ml. While stirring continuously, add 15ml of hydrochloric acid and stir until clear. Add 10ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stirring for 2 minutes. Precipitate at 15℃~25℃ and let stand for 30 minutes. Filter the solution using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper back into the beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the remaining acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath above 80°C for 3–5 minutes, remove, and immediately add 150 ml of boiling water. Titrate with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint using a potentiometric titrator. Analyze and calculate the silica content under different sample amounts; the results are shown in Table 16.

[0188] Table 16 Sampling Quantity Investigation

[0189]

[0190] The results showed that the highest content was found at a sample size of 0.1g, and the titration volume consumed at 0.2g and 0.3g was too large. Therefore, considering all factors, a sample size of 0.1g was chosen.

[0191] 3.2 Investigation of Acid Addition Amount

[0192] Take 0.1g of this product powder (batch number: BT-DQMS-21), four times in total. Accurately weigh each portion and place them in a 100ml nickel crucible containing 6g of potassium hydroxide, then mix well. Melt in a high-temperature furnace at 600℃~650℃ for 30min, then remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, washing the crucible with water, ensuring the volume does not exceed 50ml. While stirring continuously, add 15ml and 20ml of hydrochloric acid respectively, stirring until clear. Then add 10ml and 20ml of nitric acid respectively, and cool. Add an appropriate amount of potassium chloride, stirring until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stirring for 2min. Precipitate at 15℃~25℃ and let stand for 30min. Filter using rapid filter paper and a plastic funnel, wash the beaker three times with potassium chloride solution (50g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper in a beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath at above 80℃ for 3-5 minutes, remove, and immediately add 150 ml of boiling water. Use a potentiometric titrator and immediately titrate with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint. Analyze and calculate the silica content under different acid addition amounts; the results are shown in Table 17.

[0193] Table 17 Investigation of Different Acid Addition Amounts

[0194]

[0195]

[0196] The results showed that 15 ml of hydrochloric acid and 10 ml of nitric acid were sufficient, so the amount of acid added in the method was not changed.

[0197] 3.3 Determination of the amount of potassium fluoride added

[0198] The principle of the potassium fluorosilicate titration method for determining SiO2 is to decompose the sample under high temperature and strong alkaline conditions, converting insoluble SiO2 into soluble silicates. These soluble silicates react with excess fluoride and potassium ions in a strongly acidic solution to form potassium fluorosilicate precipitate. This precipitate hydrolyzes in hot water to form hydrofluoric acid, which is then titrated with a standard sodium hydroxide solution. The SiO2 content in the sample is calculated based on the amount of sodium hydroxide consumed in the titration. The reaction equation is as follows:

[0199] SiO2+6KF+4HCl→K2SiF6+4KCl+2H2O;

[0200] K2SiF6+3H2O→4HF+H2SiO3+2KF;

[0201] HF + NaOH → H₂O + NaF;

[0202] As shown in the above formula, 1 mol of SiO2 requires 6 mol of KF for precipitation. The amount of 300 g / L KF added is 5 ml, which is 0.02582 mol. The precipitable SiO2 is 0.004303 mol, equivalent to approximately 258 mg. However, based on the above results regarding sampling amount, the SiO2 content in 0.1 g of calcined chlorite standard decoction is approximately 40 mg. The amount of precipitable SiO2 is significantly greater than that in 0.1 g of calcined chlorite standard decoction. Therefore, the amount of KF added in this method is sufficient, and the amount of KF used in this method will not be further investigated.

[0203] 3.4 Investigation into the amount of potassium chloride solution added before the first titration

[0204] Take 0.1g of this product powder (batch number: BT-DQMS-21), making eight portions. Accurately weigh each portion and place them in a 100ml nickel crucible containing 6g of potassium hydroxide, then mix well. Melt the crucible in a high-temperature furnace at 600℃~650℃ for 30min, then remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, washing the crucible with water, ensuring the volume does not exceed 50ml. While stirring continuously, add 15ml of hydrochloric acid and stir until clear. Then add 10ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stirring for 2min. Precipitate at 15℃~25℃ and let stand for 30min. Filter using rapid filter paper and a plastic funnel, wash the beaker three times with potassium chloride solution (50g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper into a beaker, crush the filter paper, and add 10 ml, 20 ml, 30 ml, and 40 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L), respectively. Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath at above 80℃ for 3-5 minutes, remove, and immediately add 150 ml of boiling water. Use a potentiometric titrator and immediately titrate with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint. Analyze and calculate the silica content under different amounts of potassium chloride solution added before the first titration. The results are shown in Table 18.

[0205] Table 18 Investigation of Potassium Chloride Solution Addition Amount

[0206]

[0207]

[0208] The results showed that the content did not change significantly with the increase of potassium chloride solution added. However, because too little potassium chloride solution was added, the first titration was unevenly stirred, which could easily increase the titration endpoint error. Therefore, after comprehensive consideration, the amount of potassium chloride solution added was selected to be 20 ml.

[0209] 3.5 Investigation of the volume of boiling water added

[0210] Take 0.1g of this product powder (batch number: BT-DQMS-21), making six portions. Accurately weigh each portion and place them in a 100ml nickel crucible containing 6g of potassium hydroxide, then mix well. Melt the crucible in a high-temperature furnace at 600℃~650℃ for 30min, then remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, washing the crucible with water, ensuring the volume does not exceed 50ml. While stirring continuously, add 15ml of hydrochloric acid and stir until clear. Add 10ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stirring for 2min. Precipitate at 15℃~25℃ and let stand for 30min. Filter using rapid filter paper and a plastic funnel, wash the beaker three times with potassium chloride solution (50g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper in a beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath at above 80℃ for 3-5 minutes, remove, and immediately add 100 ml, 150 ml, and 200 ml of boiling water respectively. Use a potentiometric titrator and immediately titrate with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint. Analyze and calculate the silica content under different amounts of boiling water added; the results are shown in Table 19.

[0211] Table 19 Investigation of Boiling Water Addition Amount

[0212]

[0213] The results showed that the three different amounts of boiling water added had little effect on the content results. To ensure complete hydrolysis of the precipitate and to prevent liquid splashing during titration due to excessive sample volume, a boiling water addition of 150 ml was selected.

[0214] 3.6 Validation of the test sample preparation method

[0215] Therefore, the method for determining the silicon dioxide (SiO2) content in the calcined chlorite standard decoction is as follows: Accurately weigh approximately 0.1g of the powder and place it in a 100ml nickel crucible containing 6g of potassium hydroxide, mixing thoroughly. Melt in a high-temperature furnace at 600℃~650℃ for 30min, then remove and cool slightly. Pour small amounts of boiling water into a 300ml polyethylene beaker, washing the crucible with water, ensuring the volume does not exceed 50ml. While stirring continuously, add 15ml of hydrochloric acid and stir until clear. Add 10ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stirring for 2min. Precipitate at 15℃~25℃ and let stand for 30min. Filter using rapid filter paper and a plastic funnel, washing the beaker three times with potassium chloride solution (50g / L; water:anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper into a beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath at above 80°C for 3–5 minutes, remove, and immediately add 150 ml of boiling water. Using a potentiometric titrator, immediately titrate with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint.

[0216] 4. Methodological Investigation

[0217] 4.1 Repeatability Test

[0218] Take approximately 0.1 g of this product (batch number: BT-DQMS-21) powder, accurately weigh 6 portions, and have the same operator prepare the test solution according to the prescribed method and determine the content of silicon dioxide in the 6 test samples. The results are shown in Table 20.

[0219] Table 20 Results of Repeatability Analysis

[0220]

[0221] The results showed that the RSD value of the silica (SiO2) content obtained from the six repeatability tests was 0.7%, indicating that the method had good repeatability.

[0222] 4.2 Accuracy Examination

[0223] Take approximately 0.05 g of the test sample (batch number: BT-DQMS-21, with a silica content (SiO2) of 411.4 mg / g), in six portions. Accurately weigh each portion and add an appropriate amount of silica (SiO2) to each sample. The purity is assumed to be 99.0%. Prepare and determine the test sample solution according to the proposed method, and calculate the recovery rate.

[0224] The results are shown in Table 21, and the calculation formula is as follows:

[0225]

[0226] Table 21 Accuracy Evaluation Results

[0227]

[0228]

[0229] The results showed that the average recovery rate of silica was 99.6%, indicating that the method has good accuracy.

[0230] 4.3 Intermediate Precision Examination

[0231] The same test sample (batch number: BT-DQMS-21) was used, and different personnel (A, B) prepared the test sample solution at different times (I, II) for analysis. The silica content in the test sample was calculated, and the results are shown in Table 22.

[0232] Table 22 Results of intermediate precision test

[0233]

[0234] The results show that the RSD value for intermediate precision testing of silica content is 0.8%, indicating that the intermediate precision of this method is good.

[0235] 4.4 Linear Examination

[0236] Accurately weigh 3 mg, 6 mg, 12 mg, 24 mg, 96 mg, and 192 mg of silicon dioxide, respectively, and place them in 100 ml nickel crucibles containing 6 g of potassium hydroxide, then mix well. Melt the crucibles in a furnace at 600℃~650℃ for 30 min, then remove and let cool slightly. Pour small amounts of boiling water into a 300 ml polyethylene beaker, rinsing the crucible with water, ensuring the volume does not exceed 50 ml. While stirring continuously, add 15 ml of hydrochloric acid and stir until clear. Add 10 ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5 ml of potassium fluoride solution (300 g / L) while stirring, stirring for 2 min. Precipitate at 15℃~25℃ and let stand for 30 min. Filter using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper in a beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath above 80℃ for 3-5 minutes, remove, and immediately add 150 ml of boiling water. Using a potentiometric titrator, immediately titrate with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint. Record the volume of titrant consumed. Plot a curve with the amount of silica sampled (X, mg) on ​​the x-axis and the volume of titrant consumed (Y, ml) on the y-axis. The results are shown in Table 23. Figure 2 .

[0237] Table 23 Results of the linear experiment

[0238]

[0239] The results showed that the linear relationship between the sample amount of silica and the titration volume was y = 1.0729x - 4.2491, with an R² value of 0.9991, indicating that silica exhibited a good linear relationship in the range of 3.97 mg to 192.351 mg.

[0240] 4.5 Verification

[0241] Multiple batches of samples were tested to verify whether the established method was suitable for testing all samples. The results are shown in Table 24.

[0242] Table 24. Analysis Results of Standard Decoctions

[0243]

[0244] Example 6: Establishment of a method for determining the particle content of calcined chlorite in a formulation.

[0245] 1. Materials, Reagents and Instruments

[0246] Electronic balances: ME204E / 02, MS205DM, XP26 (Mettler-Toledo Instruments Ltd.);

[0247] Ultrapure water system: Cellular type 1810A (Shanghai Moler Scientific Instruments Co., Ltd.);

[0248] Ultrasonic cleaner: KQ-600DB model (600W, 40KHz; Kunshan Ultrasonic Instrument Co., Ltd.);

[0249] Box-type electric furnace: SX2 (manufactured by Shanghai Pudong Rongfeng Scientific Instruments Co., Ltd. and Shanghai Shengxin Scientific Instruments Co., Ltd.);

[0250] Potentiometric titrator: G10S (Mettler-Toledo Instruments Ltd.);

[0251] 50ml burette; 30ml nickel crucible; 100ml nickel crucible; 300ml plastic beaker, etc.

[0252] Potassium hydroxide, hydrochloric acid, nitric acid, potassium chloride, potassium fluoride, anhydrous ethanol, phenolphthalein, sodium hydroxide, silicon dioxide, and other reagents were all of analytical grade. Potassium hydrogen phthalate was used as a primary standard, and the water was ultrapure water.

[0253] Calcined chlorite (biotite schist) formulation granules (batch numbers: KL-DQMS-01, KL-DQMS-02, KL-DQMS-03).

[0254] 2. Determine the experimental method

[0255] The content of chlorite (biotite schist) medicinal material and calcined chlorite (biotite schist) decoction pieces and calcined chlorite (biotite schist) was tested according to the standard decoction method. The specific method is as follows:

[0256] Take an appropriate amount of this product, grind it into a fine powder, and accurately weigh approximately 0.1g. Place the powder in a 100ml nickel crucible containing 6g of potassium hydroxide and mix well. Melt the crucible in a high-temperature furnace at 600℃~650℃ for 30 minutes, then remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, wash the crucible with water, and control the volume to not exceed 50ml. While stirring continuously, add 15ml of hydrochloric acid and stir until clear. Add 10ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stir for 2 minutes, and precipitate at 15℃~25℃ for 30 minutes. Filter using rapid filter paper and a plastic funnel, wash the beaker three times with potassium chloride solution (50g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper into a beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath at above 80°C for 3–5 minutes, remove, and immediately add 150 ml of boiling water. Using a potentiometric titrator, immediately titrate with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint.

[0257] 3. Preparation of test solution

[0258] 3.1 Sample Quantity Assessment

[0259] Take an appropriate amount of this product (batch number: KL-DQMS-01), grind it finely, and accurately weigh approximately 0.2g, 0.5g, and 1.0g, placing them separately into 100ml nickel crucibles containing 6g of potassium hydroxide, and mix well. Melt in a high-temperature furnace at 600℃~650℃ for 30min, then remove and cool slightly. Pour the molten material into a 300ml polyethylene beaker in small amounts several times with boiling water, washing the crucible with water, controlling the volume to not exceed 50ml. While stirring continuously, add 15ml of hydrochloric acid and stir until clear. Add 10ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stirring for 2min, and precipitate at 15℃~25℃ for 30min. Filter the solution using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper back into the beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the remaining acid with standard sodium hydroxide solution (0.1 mol / L), squeezing the filter paper and precipitate until the solution just turns red and does not fade (ignoring the volume of the standard sodium hydroxide solution). Incubate in a water bath above 80°C for 3–5 minutes, remove, and immediately add 150 ml of boiling water. Titrate with standard sodium hydroxide solution (0.1 mol / L) to the endpoint using a potentiometric titrator. Analyze and calculate the silica content under different sample amounts; the results are shown in Table 25.

[0260] Table 25 Sampling Quantity Investigation

[0261]

[0262] The results showed that there was no significant difference in content among the three sampling amounts. The volume of titrant consumed was too large for 1g, while the volume consumed was too small for 0.2g. To ensure the accuracy of the determination, the sampling amount of 0.5g was selected after comprehensive consideration.

[0263] 3.2 Investigation of Acid Addition Amount

[0264] Take an appropriate amount of this product (batch number: KL-DQMS-01), grind it finely, and take about 0.5g, making four portions. Accurately weigh each portion and place them in a 100ml nickel crucible containing 6g of potassium hydroxide, and mix well. Melt the crucible in a high-temperature furnace at 600℃~650℃ for 30min, then remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, wash the crucible with water, and control the volume to not exceed 50ml. While stirring continuously, add 15ml and 20ml of hydrochloric acid respectively, stirring until clear. Then add 10ml and 20ml of nitric acid respectively, and cool. Add an appropriate amount of potassium chloride, and stir until the test solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stir for 2min, precipitate at 15℃~25℃ and let stand for 30min. Filter the solution using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper back into the beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with standard sodium hydroxide solution (0.1 mol / L), squeezing the filter paper and precipitate until the solution just turns red and does not fade (ignoring the volume of the standard sodium hydroxide solution). Incubate in a water bath above 80°C for 3–5 minutes, remove, and immediately add 150 ml of boiling water. Titrate with standard sodium hydroxide solution (0.1 mol / L) to the endpoint using a potentiometric titrator. Analyze and calculate the silica content under different acid addition amounts; the results are shown in Table 26.

[0265] Table 26 Investigation of Different Acid Addition Amounts

[0266]

[0267] The results showed that 15 ml of hydrochloric acid and 10 ml of nitric acid were sufficient, so the amount of acid added in the method was not changed.

[0268] 3.3 Investigation into the amount of potassium chloride solution added before the first titration

[0269] Take an appropriate amount of this product (batch number: KL-DQMS-01), grind it finely, and accurately weigh about 0.5g. Place it in a 100ml nickel crucible containing 6g of potassium hydroxide and mix well. Melt it in a high-temperature furnace at 600℃~650℃ for 30min, then remove and cool slightly. Pour the molten material into a 300ml polyethylene beaker in small amounts several times with boiling water, wash the crucible with water, and control the volume to not exceed 50ml. Add 15ml of hydrochloric acid while stirring continuously until clear. Add 10ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml of potassium fluoride solution (300g / L) while stirring, stir for 2min, precipitate at 15℃~25℃ and let stand for 30min. Filter with rapid filter paper and a plastic funnel, wash the beaker 3 times with potassium chloride solution (50g / L; water: anhydrous ethanol 1:1), and precipitate 8 times. Place the precipitate and filter paper into a beaker, crush the filter paper, and add 10 ml, 20 ml, 30 ml, and 40 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L), respectively. Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath at above 80℃ for 3-5 minutes, remove, and immediately add 150 ml of boiling water. Use a potentiometric titrator and immediately titrate with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint. Analyze and calculate the silica content under different amounts of potassium chloride solution added before the first titration. The results are shown in Table 27.

[0270] Table 27 Investigation on the Amount of Potassium Chloride Solution Added

[0271]

[0272] The results showed that the content did not change significantly with the increase of potassium chloride solution added. However, because too little potassium chloride solution was added, the first titration was unevenly stirred, which could easily increase the titration endpoint error. Therefore, after comprehensive consideration, the amount of potassium chloride solution added was selected to be 20 ml.

[0273] 3.4 Validation of test sample preparation method and assay method

[0274] Therefore, the method for determining the silica (SiO2) content in the calcined chlorite (biotite schist) formulation granules is as follows: Take an appropriate amount of this product, grind it finely, and accurately weigh approximately 0.5g. Place each 0.5g granules into a 100ml nickel crucible containing 6g potassium hydroxide and mix well. Melt the crucible in a high-temperature furnace at 600℃~650℃ for 30min, then remove and cool slightly. Pour the melt into a 300ml polyethylene beaker in small amounts several times with boiling water, wash the crucible with water, and control the volume to not exceed 50ml. Add 15ml hydrochloric acid while stirring continuously until clear. Add 10ml nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5ml potassium fluoride solution (300g / L) while stirring, stir for 2min, precipitate at 15℃~25℃ and let stand for 30min. Filter using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper back into the beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the remaining acid with standard sodium hydroxide solution (0.1 mol / L), squeezing the filter paper and precipitate until the solution just turns red and does not fade (ignoring the volume of the standard sodium hydroxide solution). Incubate in a water bath above 80°C for 3–5 minutes, remove, and immediately add 150 ml of boiling water. Titrate with standard sodium hydroxide solution (0.1 mol / L) to the endpoint using a potentiometric titrator.

[0275] 4 Methodology

[0276] 4.1 Specificity test

[0277] The test solution, excipients, and solvent blank were prepared according to the proposed test sample preparation method, and the results were determined according to the proposed method. The results are shown in Table 28 below.

[0278] Table 28 Results of Specificity Analysis

[0279]

[0280] The results show that the method has good specificity and can determine the content of calcined chlorite (biotite schist) formulation particles without interference from negative samples.

[0281] 4.2 Repeatability Test

[0282] Take an appropriate amount of this product (batch number: KL-DQMS-01), grind it into a fine powder, take about 0.5g, accurately weigh 6 portions, and have the same operator prepare the test solution according to the proposed method and determine the content of silicon dioxide in the 6 test samples. The results are shown in Table 29.

[0283] Table 29 Results of Repeatability Analysis

[0284]

[0285] The results showed that the RSD value of the silica (SiO2) content obtained from the six repeatability tests was 0.9%, indicating that the method had good repeatability.

[0286] 4.3 Linear Relationship

[0287] Accurately weigh 3 mg, 6 mg, 12 mg, 24 mg, 96 mg, and 192 mg of silicon dioxide, respectively, and place them in 100 ml nickel crucibles containing 6 g of potassium hydroxide, then mix well. Melt the crucibles in a furnace at 600℃~650℃ for 30 min, then remove and let cool slightly. Pour small amounts of boiling water into a 300 ml polyethylene beaker, rinsing the crucible with water, ensuring the volume does not exceed 50 ml. While stirring continuously, add 15 ml of hydrochloric acid and stir until clear. Add 10 ml of nitric acid and cool. Add an appropriate amount of potassium chloride and stir until the solution is saturated and a small amount of potassium chloride remains undissolved. Slowly add 5 ml of potassium fluoride solution (300 g / L) while stirring, stirring for 2 min. Precipitate at 15℃~25℃ and let stand for 30 min. Filter using rapid filter paper and a plastic funnel. Wash the beaker three times with potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and precipitate eight times. Place the precipitate and filter paper in a beaker, crush the filter paper, add 20 ml of potassium chloride solution (50 g / L; water: anhydrous ethanol 1:1), and 5 drops of phenolphthalein ethanol solution (10 g / L). Titrate the unwashed acid with sodium hydroxide standard titration solution (0.1 mol / L), squeezing the filter paper and precipitate until the test solution just turns red and does not fade (ignoring the volume of sodium hydroxide standard titration solution). Incubate in a water bath above 80℃ for 3-5 minutes, remove, and immediately add 150 ml of boiling water. Using a potentiometric titrator, immediately titrate with sodium hydroxide standard titration solution (0.1 mol / L) to the endpoint. Record the volume of titrant consumed. Plot a curve with the amount of silica sampled (X, mg) on ​​the x-axis and the volume of titrant consumed (Y, ml) on the y-axis. The results are shown in Table 30. Figure 3 .

[0288] Table 30 Results of the linearity test

[0289]

[0290] The results showed that the linear relationship between the sample amount of silica and the titration volume was y = 1.0729x - 4.2491, with an R² value of 0.9991, indicating that silica exhibited a good linear relationship in the range of 3.97 mg to 192.351 mg.

[0291] 4.4 Accuracy Test

[0292] Take a known sample (batch number: KL-DQMS-01, silica content (SiO2) of 49.7 mg / g), grind it into a fine powder, take about 0.25 g, make 6 portions, weigh them accurately, add an appropriate amount of silica (SiO2) to each portion accurately, with a purity of 99.0%, prepare and determine the sample solution according to the proposed method, and calculate the recovery rate.

[0293] The results are shown in Table 31, and the calculation formula is as follows:

[0294]

[0295] Table 31 Accuracy Evaluation Results

[0296]

[0297] The results showed that the average recovery rate of silica was 98.0%, indicating that the method has good accuracy.

[0298] 4.5 Intermediate Precision Test

[0299] The same test sample (batch number: KL-DQMS-01) was used, and different personnel (A, B) prepared test sample solutions at different times (I, II) for analysis. The silica content in the test sample was calculated, and the results are shown in Table 32.

[0300] Table 32 Results of intermediate precision test

[0301]

[0302] The results show that the RSD value of silica content under the intermediate precision test is 1.0%, indicating that the intermediate precision of this method is good.

[0303] 4.6 Verification

[0304] Multiple batches of samples were tested to verify whether the established method was suitable for testing all samples. The results are shown in Table 33.

[0305] Table 33 Results of Formulation Granule Validation Analysis

[0306]

[0307] Conclusion: The method for determining the silica content of calcined chlorite (biotite schist) formulation particles can effectively detect the silica content of calcined chlorite (biotite schist) formulation particles, therefore this method is included in the main text of calcined chlorite (biotite schist) formulation particles.

[0308] This method is applicable to the determination of the content of chlorite medicinal materials, calcined chlorite slices, calcined chlorite standard decoctions, and calcined chlorite formula granules. It can comprehensively control the content of components in chlorite medicinal materials, calcined chlorite slices, standard decoctions, and formula granules, ensuring the overall stability of the quality of chlorite medicinal materials, calcined chlorite slices, standard decoctions, and formula granules. Moreover, the method is simple to operate, has high precision, good stability, good repeatability, and high accuracy.

Claims

1. A method for determining the content of chlorite medicinal material and its preparations, characterized in that: It includes the following steps: a. Melting: Take Qingmengshi medicinal materials and their preparations, add potassium hydroxide, and melt them in a high-temperature furnace; b. Leaching and acidification: Leach the molten metal from step a with boiling water; add hydrochloric acid and nitric acid sequentially to the leaching solution while stirring, and then cool. c. Precipitation: Add potassium chloride until the test solution is saturated, then slowly add potassium fluoride solution, stir, let stand, and a precipitate will form; d. Filtration and washing: Filtration, washing with potassium chloride-ethanol solution, and precipitation; e. Acid washing and neutralization: Transfer the precipitate and filter paper back to the beaker, crush the filter paper, add washing solution and phenolphthalein indicator, and titrate the residual acid with NaOH until it turns slightly red. f. Titration: After keeping warm in a water bath, add boiling water and immediately titrate with NaOH using a potentiometric titrator to the endpoint, then calculate the SiO2 content.

2. The method for determining the content of chlorite medicinal material and its preparations according to claim 1, characterized in that: The melting time in step a is 30 minutes; the mass ratio of chlorite to potassium hydroxide in step a is 0.1:6; and the melting temperature is 600–650℃.

3. The method for determining the content of chlorite medicinal material and its preparations according to claim 1, characterized in that: In step b, hydrochloric acid is added to the extract under stirring until it becomes clear, then nitric acid is added and the mixture is cooled. For every 0.1g of Qingmengshi medicinal material and its preparations, 15ml of hydrochloric acid and 10ml of nitric acid are added.

4. The method for determining the content of chlorite medicinal material and its preparations according to claim 1, characterized in that: In step c, the concentration of the potassium fluoride solution is 300 g / L, and the stirring time is 2 min; the settling temperature in step c is 15℃~25℃, and the time is 30 min.

5. The method for determining the content of chlorite medicinal material and its preparations according to claim 1, characterized in that: The concentration of potassium chloride in the potassium chloride-ethanol solution described in step d is 50 g / L; the volume ratio of water to anhydrous ethanol is 1:1; the washing frequency in step d is 3 times, and the precipitation frequency is 8 times.

6. The method for determining the content of chlorite medicinal material and its preparations according to claim 1, characterized in that: The washing solution described in step e is a potassium chloride solution with a concentration of 50 g / L. The dosage is 20 ml of potassium chloride per 0.1 g of chlorite, and the volume ratio of water to anhydrous ethanol is 1:

1. The concentration of the phenolphthalein ethanol solution is 10 g / L.

7. The method for determining the content of chlorite medicinal material and its preparations according to claim 1, characterized in that: The water bath temperature in step f is 80℃, and the water bath is kept warm for 3–5 minutes. The concentration of NaOH is 0.1 mol / L. The amount of boiling water used is 150 ml of boiling water per 0.1 g of chlorite.

8. The method for determining the content of chlorite medicinal material and its preparations according to claim 1, characterized in that: The formula for calculating the SiO2 content in step f is as follows: In the formula: C — the concentration of the sodium hydroxide standard titration solution, in moles per liter (mol / L); V—The volume of sodium hydroxide standard titration solution consumed during titration of the test solution, in milliliters (ml); V1—The volume of sodium hydroxide standard titration solution consumed when titrating the blank solution, in milliliters (ml); M1—Molar mass of silicon dioxide, 60.0, in grams per mole (g / mol); m1 — Mass of the sample, in grams (g); After the reaction of 4-1 / 4 mol of silicon dioxide, the titration consumes 1 mol of sodium hydroxide.

9. The method for determining the content of chlorite medicinal material and its preparations according to any one of claims 1-8, characterized in that: The aforementioned chlorite medicinal materials and their preparations include chlorite medicinal materials, calcined chlorite slices, chlorite standard decoction, and calcined chlorite formula granules.

10. The method for determining the content of chlorite medicinal material and its preparations according to claim 9, characterized in that: The silica content in the chlorite medicinal material is 39.9-53.1%; the silica content in the calcined chlorite slices is 46.7-55.3%; the silica content in the calcined chlorite standard decoction is 353.2-469.7 mg / g; and the silica content in the calcined chlorite granules is 49.5-51.0 mg / g.

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