Method for extracting double solvents in organic solution

Abstract

The invention discloses a double-solvent extraction method in an organic solution, and belongs to the technical field of solvent extraction methods in organic solutions. The method comprises the following steps: mixing an original solution with a solvent S1 serving as an organic extraction agent and a solvent S2 serving as an inorganic extraction agent to obtain a solution 1; after the solution 1 is subjected to multiple times of step-by-step extraction, an extraction phase E1, an extraction phase E2 and a raffinate phase R are generated respectively; and separating the extract liquor to respectively obtain extract liquor E01, extract liquor E02 and raffinate R0. The method disclosed by the invention is simple and rapid to operate, good in selectivity, good in separation effect, relatively high in extraction rate, capable of obtaining a relatively pure solvent, wide in application range and capable of effectively separating organic matters and inorganic matters in an organic solution at the same time.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of solvent extraction method in organic solution, and particularly relates to a double-solvent extraction method in organic solution. BACKGROUND

[0002] At present, the content of inorganic substances in organic solution often needs to be detected in daily chemical analysis, which requires the separation and pretreatment of organic solvents. The commonly used method is solvent extraction method. This method can effectively separate the general solution by using the principle of similar compatibility, but the operation is relatively complex, and there is incomplete extraction phenomenon. Moreover, if the organic solution itself has complex composition, it is easy to cause various side reactions and make the extraction fail. The application provides an extraction method, which is mainly used for the separation of inorganic solvents in organic solution. The extraction method maximizes the extraction rate and can ensure the effectiveness of the extraction process. The separated solution provides a reliable and stable basis for subsequent detection and analysis.

[0003] CN116693369A discloses a continuous countercurrent extraction method of resorcinol, which mainly uses the method of extracting resorcinol from the hydrolysis liquid of resorcinol prepared by hydrolysis of m-phenylenediamine. Multistage countercurrent extraction is to add organic phase and aqueous phase from both ends of the multistage extractor, and the two phases flow countercurrently. In each extractor, the two phases are subjected to sufficient contact and clarification separation process, and then enter two adjacent extractors.

[0004] CN114307248A discloses an organic solvent liquid-liquid extraction automation device, which belongs to the technical field of extraction device.

[0005] The above two patents do not have similar contents to the present patent. CN116693369A continuous countercurrent extraction method is different from the extraction method of the present patent, and the method is only applicable to resorcinol. CN114307248A mainly tends to design the extraction device. SUMMARY

[0006] The purpose of the present application is to provide a double-solvent extraction method in organic solution, which separates inorganic substances from organic solvents by multiple step-by-step extraction methods, and can obtain relatively pure inorganic aqueous solution. It can also provide a good basis for subsequent inorganic substance detection work.

[0007] To solve the above technical problems, the application adopts the following technical scheme:

[0008] The double-solvent extraction method in organic solution mixes the original solution with the solvent S1 as the organic extractant and the solvent S2 as the inorganic extractant into solution 1.

[0009] Solution 1 is subjected to multiple stepwise extraction to produce extraction phase E1, extraction phase E2 and raffinate phase R respectively;

[0010] The extraction liquid is separated to obtain extraction liquid E01, extraction liquid E02 and raffinate liquid R0 respectively.

[0011] Further, it specifically includes:

[0012] Mixing and oscillation: after selecting the extractant, the original solution is mixed with solvent S1 as the organic extractant and solvent S2 as the inorganic extractant in solution 1 to the closed separatory funnel, and oscillated manually or using an oscillator to make the two phases fully contact; the oscillation time is 5-30 minutes, and vigorous oscillation is avoided to prevent emulsification; after multiple repeated mixing operations, extraction phase E1, extraction phase E2 and raffinate phase R0 are formed;

[0013] Static layering: after oscillation, the separatory funnel is left to stand for 10-30 minutes to allow the two phases to separate naturally; the phase with higher density is in the lower layer, and the phase with lower density is in the upper layer, and whether the layering is complete is determined by observing the clarity of the interface;

[0014] Separation operation: after complete layering, the piston of the separatory funnel is opened, and the lower layer liquid is slowly discharged into a clean container; the piston is closed, and the upper layer liquid is poured into another container to collect the extraction phase and the raffinate phase containing the target substance respectively. If multiple repeated extractions are required, the separated extraction liquids are mixed to obtain extraction liquid E01, extraction liquid E02 and raffinate liquid R0 respectively;

[0015] ③Subsequent treatment

[0016] Washing and purification: to remove impurities in the extraction phase, an appropriate amount of washing liquid is used for washing; the extraction phase and the washing liquid are added to the separatory funnel for oscillation, standing and separation, which is repeated 2-3 times;

[0017] Drying and water removal: trace amounts of water in the extraction phase are removed using a drying agent; the drying agent is added to the extraction phase, which is oscillated and then left to stand for a period of time, and the drying agent is removed by filtration;

[0018] Concentration and enrichment: the solvent in the extraction phase is evaporated to concentrate and enrich the extracted substance.

[0019] Further, attention should be paid to the fact that the mixing process should not be too vigorous, and it should be carried out in a fume hood with appropriate exhaust operation.

[0020] Further, if emulsification occurs, methods such as stirring, heating, adding salt and centrifugation can be used to break the emulsion.

[0021] Further, if the extraction effect is still not ideal, the extraction phases E1 and E2 are added with appropriate amounts of extractant respectively to repeat the above mixing operation.

[0022] Further, the washing liquid is water, dilute acid, dilute alkali or saturated brine.

[0023] Further, the drying agent is anhydrous sodium sulfate, anhydrous magnesium sulfate or calcium oxide.

[0024] Further, the solvent in the extraction phase is evaporated by using a rotary evaporator and a reduced pressure distillation method to concentrate and enrich the extracted substance, and ice is set at a suitable temperature, pressure and rotation speed to avoid loss or decomposition.

[0025] Further, the volume ratio of the extraction agent to the original solution is 1:1-1:5.

[0026] Compared with the prior art, the present application has the beneficial technical effects of:

[0027] The present application has the advantages of simple and rapid operation, good selectivity, good separation effect, high extraction rate, ability to obtain relatively pure solvent, wide application range and ability to simultaneously effectively separate organic matter and inorganic matter in an organic solution. BRIEF DESCRIPTION OF DRAWINGS

[0028] The present application will be further described below in combination with the description of the accompanying drawings.

[0029] Figure 1 The accompanying drawings show the flowchart of the double-solvent extraction method of the present application. DETAILED DESCRIPTION

[0030] ① Selection of extraction agent

[0031] The appropriate organic extraction agent can be selected according to the actual needs and the extracted organic solution. Generally, the selected types are roughly divided into hydrocarbons: benzene, gasoline, etc.; ethers: diethyl ether, petroleum ether, straight-run ether, etc.; esters: butyl acetate, trimethyl phosphonate, etc.; alcohols: ethanol, isopropyl alcohol, etc.; ketones: acetone, butanone, etc.; and other common extraction agents: carbon tetrachloride, chloroethylene, etc. The appropriate extraction agent is selected according to the properties of the extracted substance and the sample itself. For example, for polar extracted substances, extraction agents with similar polarity such as methanol and ethanol can be selected, and for non-polar extracted substances, non-polar extraction agents such as n-hexane and petroleum ether can be selected. The extraction agent is required to have high solubility for the extracted substance, be immiscible with the original solvent, have good chemical stability, low toxicity and be easy to recover. The inorganic extraction agent can also be regarded as an inorganic solvent, and generally, tertiary water is selected as the extraction agent for inorganic substances. If there is a special sample to be treated, inorganic acid, alkali and other solvents can be selected. The extraction operation is carried out according to the extraction principle and steps shown in the above figure. The specific implementation steps are as follows:

[0032] ② Extraction process

[0033] Instrument preparation: according to the actual nature of the sample, select the preparation of separatory funnel, shaker, centrifuge, rotary evaporator, balance, pH meter, etc. The separatory funnel is selected according to the processing capacity to ensure that it is clean, undamaged, and the piston is tightly sealed; the shaker can provide stable oscillation frequency and amplitude; the centrifuge has different speed adjustment functions; the rotary evaporator can effectively evaporate the solvent.

[0034] Sample pretreatment: If the sample is solid, it needs to be crushed and ground to increase the contact area with the extractant, or to be digested and dissolved; liquid samples are adjusted according to the situation, and complexing agents, masking agents, etc. are added to improve the extraction selectivity and efficiency. For example, adjust the pH of the sample to a certain range, so that the extracted substance exists in a certain form, which is beneficial to extraction.

[0035] Selection and addition of extractant: After pretreatment, the sample is transferred to the separatory funnel, and the extractant is added according to a certain proportion. Generally, the volume ratio of extractant to sample solution is 1:1-1:5, which can be adjusted according to the distribution coefficient of the extracted substance, sample concentration and extraction efficiency requirements.

[0036] Mixing and oscillation: After selecting the extractant, the original solution, the same solvent S1 (representing organic extractant) and the solvent S2 (representing inorganic extractant) are mixed together into solution 1 to close the separatory funnel, and manually or using a shaker to oscillate, so that the two phases are fully contacted. Note that the mixing process should not be too violent, and it should be carried out in a fume hood, and appropriate exhaust operation should be carried out. The oscillation time is usually 5-30 minutes to avoid emulsification phenomenon caused by violent oscillation. If emulsification occurs, methods such as stirring, heating, adding salt, centrifugation, etc. can be used to break the emulsion. After repeated mixing operations, the extraction phase E1, the extraction phase E2 and the raffinate phase R are formed. If the extraction effect is still not ideal, the extraction phases E1 and E2 can be added with appropriate amount of extractant to repeat the above mixing operation. Especially for organic solution extraction with temperature requirements, it often needs to be carried out at a suitable temperature, so it also needs to consider preheating the extracted original liquid according to the actual situation, and then carry out rapid hot extraction according to the above method.

[0037] Static layering: After oscillation, the separatory funnel is left to stand for 10-30 minutes to allow the two phases to separate naturally. The phase with high density is in the lower layer, and the phase with low density is in the upper layer. The clarity of the interface is observed to determine whether the layering is complete.

[0038] Separation operation: After complete layering, open the piston of the separatory funnel, slowly release the lower layer liquid into a clean container; close the piston, pour the upper layer liquid into another container, and collect the extraction phase and the raffinate phase containing the target substance respectively. If multiple repeated extractions are required, the separated extraction liquids are mixed together to obtain extraction liquids E01, E02 and raffinate liquid R0 respectively.

[0039] ③Subsequent treatment

[0040] Washing purification: to remove impurities in the extraction phase, with the appropriate amount of washing liquid (such as water, dilute acid, dilute alkali, saturated brine, etc.) washing. The extraction phase and washing liquid into the separatory funnel, shaking, standing, liquid separation, repeated 2-3 times.

[0041] Drying water removal: using desiccant to remove trace amounts of water in the extraction phase, commonly used desiccants are anhydrous sodium sulfate, anhydrous magnesium sulfate, calcium oxide, etc. The desiccant is added to the extraction phase, shaken and then left for a period of time, and the desiccant is filtered out.

[0042] Concentration enrichment: using a rotary evaporator, vacuum distillation and other methods to evaporate the solvent in the extraction phase, so that the extracted material is concentrated and enriched. Set the appropriate temperature, pressure and speed to avoid loss or decomposition.

[0043] (7) Laboratory application examples

[0044] Laboratory oil washing solution extraction method and process:

[0045] Washing oil is an important fraction in the processing of coal tar, usually brownish oil liquid, viscous and poor flow at room temperature. Its composition is relatively complex, mainly containing aromatic hydrocarbons (such as naphthalene, methyl naphthalene, dimethyl naphthalene, etc.), a small amount of unsaturated hydrocarbons and heterocyclic compounds containing nitrogen, oxygen and sulfur (such as quinoline, indole, carbazole, etc.). In order to carry out subsequent detection work, it is necessary to effectively separate the organic matter in the washing oil from the inorganic matter, and exclude the detection interference, and carry out extraction test.

[0046] According to the extraction needs, select and prepare the separatory funnel, shaker, balance and other test equipment, use the graduated cylinder to measure 100 mL of washing oil solution, select 50 mL of petroleum ether as the extractant for extracting the main organic solvent in the washing oil; measure 100 mL of distilled water at about 50°C as the solution of inorganic matter. (Since the washing oil is relatively viscous, the distilled water needs to be preheated to control the temperature between 50-60°C, which can not only ensure good separation effect, but also prevent the organic matter from decomposing and volatilizing at this temperature.) Mix the three into the separatory funnel and place and fix it on the shaker. To avoid shaking too fast and causing the solution to emulsify, use low-speed shaking. Adjust the shaking frequency to 10 Hz (10 times per second) for 20 minutes, and observe the actual extraction during the period. Vent 2 times. After shaking, stand for 30 minutes to observe the separation and extraction effect. After extraction, carry out liquid separation operation. To ensure sufficient reagent for subsequent processing, the above method is used for 2 times extraction, and 196 mL of inorganic water solution and 302 mL of organic solution are obtained respectively. Use 100 mL of saturated brine to add to 100 mL of extraction phase, add to the separatory funnel, shake, stand, and separate, repeat 2 times to wash the extraction phase, and obtain the organic solution with less impurities. The inorganic solution is further filtered by 2 times medium-speed filter paper to obtain a relatively pure inorganic solution.

[0047] Because the components of the washing oil are complex, the mass of naphthalene contained therein is used as the basis for calculating the extraction rate. The original washing oil sample contains 12.6% naphthalene, and the extraction phase contains 12.1% naphthalene, with an extraction rate of 96.03% and a loss of 3.97%. The loss rate is mainly caused by the complex components of the washing oil, wherein a part is carried out by gas generated during the extraction process, and a part is caused by the washing oil that is not completely washed away during the subsequent washing process, and in addition, the error in the detection operation process. However, for such complex organic mixtures, satisfactory extraction results can be obtained, which has little effect on the error of the subsequent detection work. At the same time, the inorganic solution can discharge the interference of organic matter, and the detection of the content of chloride ions has a high guiding significance for production.

[0048] Comparison with other extraction methods:

[0049] CN116693369A is an extraction method for only a single organic solution of resorcinol, which is not suitable for more complex mixed organic solutions. The specific test process and data results are as follows:

[0050] Test process: 6000g of salt solution containing 6.5% resorcinol and 3000g of extractant (methyl isobutyl ketone or cyclohexanol or cyclohexanone) are prepared. Start the three-stage centrifugal extractor, and adjust the speed to 3000rpm. Use the metering pump to feed, and the resorcinol salt solution metering pump feeding speed is 200g / min, which enters from the feeding port of the first-stage centrifugal extractor; the extractant metering pump feeding speed is 100g / min, which enters from the feeding port of the three-stage centrifugal extractor, and the three-stage countercurrent centrifugal extraction is carried out. After the extraction is completed, the residual material in the centrifugal machine is discharged, and the oil layer is separated.

[0051] Data results: 3392.5g of oil layer is obtained, wherein the content of resorcinol is 11.4%, and the extraction efficiency reaches 99.2%. 5582.5g of wastewater is collected, and the content of resorcinol therein is 0.056% after analysis. In addition, 25g of material is left in the centrifugal machine during the extraction process.

[0052] The extractant methyl isobutyl ketone selected in the above method is not suitable for this project, and the centrifugal extraction with high speed is not suitable for this project, and the change of the sample property state during the centrifugal process of the complex organic matter is not fully considered. This method is highly targeted, and the test process is flexible and controllable, and is mainly used for the separation of complex mixed organic matter.

[0053] CN114307248A An organic solvent liquid-liquid extraction automation device, which provides an organic solvent liquid-liquid extraction automation device, belonging to the technical field of extraction device, the organic solvent liquid-liquid extraction automation device includes base, the upper surface of base is fixedly connected with partition, the outer surface of partition is opened on one side with through hole. Through the setting of through hole, fan, pipe, waste gas collection tank, flow guide, filter screen, chute and waste liquid collection tank, when the experimenter accidentally drops the organic solution out of the solution bottle, the fan can be started. The fan in the through hole can produce air flow after rotating, the odor emitted by the organic solution is sucked into the waste gas collection tank through the pipe, at the same time, the solution or pure water that can dissolve organic matter can be added in the waste liquid collection tank, the excess organic solution flows into the filter screen through the flow guide, and then falls into the waste liquid collection tank, after collection, the waste liquid collection tank can be directly pulled out through the chute, so that the organic solution is collected and treated, and harm to the experimenter caused by toxic organic solution is avoided.

[0054] The application belongs to the technical field of extraction device and has no comparability and relevance with the project.

[0055] The above-mentioned embodiments only describe the preferred modes of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements of the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A method of double solvent extraction in an organic solution, characterized by, Comprising: The original solution is mixed with solvent S1 as the organic extractant and solvent S2 as the inorganic extractant to form solution 1; After multiple step-by-step extractions, the extraction solution is separated to obtain extraction solution E01, extraction solution E02, and raffinate R0. Specifically comprising:

2. The method of claim 1, wherein the organic solvent is selected from the group consisting of methanol, ethanol, isopropanol, acetonitrile, acetone, methyl ethyl ketone, dimethylformamide, dimethylsulfoxide, and mixtures thereof. Mixing and oscillation: After selecting the extractant, the original solution is mixed with solvent S1 as the organic extractant and solvent S2 as the inorganic extractant to form solution 1 in a closed separatory funnel. Manual or oscillation is used to oscillate and make the two phases fully contact. The oscillation time is 5-30 minutes to avoid emulsification caused by vigorous oscillation. After multiple repeated mixing operations, extraction phase E1, extraction phase E2, and raffinate R0 are formed; Static layering: After oscillation, the separatory funnel is left to stand for 10-30 minutes to allow the two phases to separate naturally. The phase with high density is in the lower layer, and the phase with low density is in the upper layer. The degree of clear separation of the interface is observed to determine whether the layering is complete; Separation operation: After complete layering, the lower layer liquid is slowly discharged into a clean container by opening the piston of the separatory funnel. The upper layer liquid is poured into another container to collect the extraction phase and the raffinate phase containing the target substance. If multiple repeated extractions are required, the separated extraction solutions are mixed to obtain extraction solution E01, extraction solution E02, and raffinate R0; ③Subsequent processing Washing and purification: To remove impurities in the extraction phase, an appropriate amount of washing liquid is used. The extraction phase and washing liquid are added to the separatory funnel, oscillated, left to stand, and separated. The operation is repeated 2-3 times; Drying and water removal: A drying agent is used to remove trace amounts of water in the extraction phase. The drying agent is added to the extraction phase, oscillated, and left to stand for a period of time. The drying agent is removed by filtration; Concentration and enrichment: The solvent in the extraction phase is evaporated to concentrate and enrich the extracted substance. Note that the mixing process should not be too vigorous, and it should be carried out in a fume hood with proper exhaust operation.

3. The method of claim 2, wherein the organic solvent is selected from the group consisting of methanol, ethanol, isopropanol, acetonitrile, acetone, methyl ethyl ketone, dimethylformamide, dimethylsulfoxide, and mixtures thereof. If emulsification occurs, methods such as stirring, heating, adding salt, and centrifugation can be used to break the emulsion.

4. The method of claim 1, wherein the organic solvent is selected from the group consisting of methanol, ethanol, isopropanol, acetonitrile, acetone, methyl ethyl ketone, dimethylformamide, dimethylsulfoxide, and mixtures thereof. If the extraction effect is still not ideal, the extraction phases E1 and E2 are added with appropriate amounts of extractant to repeat the above mixing operation.

5. The method of claim 1, wherein the organic solvent is selected from the group consisting of methanol, ethanol, isopropanol, acetonitrile, acetone, methyl ethyl ketone, dimethylformamide, dimethylsulfoxide, and mixtures thereof. The washing liquid is water, dilute acid, dilute base, or saturated brine.

6. The method of claim 1, wherein the organic solvent is selected from the group consisting of methanol, ethanol, isopropanol, acetonitrile, acetone, methyl ethyl ketone, dimethylformamide, dimethylsulfoxide, and mixtures thereof. The drying agent is anhydrous sodium sulfate, anhydrous magnesium sulfate, or calcium oxide.

7. The method of claim 1, wherein the organic solvent is selected from the group consisting of methanol, ethanol, isopropanol, acetonitrile, acetone, methyl ethyl ketone, dimethylformamide, dimethylsulfoxide, and mixtures thereof. A rotary evaporator or reduced pressure distillation method is used to evaporate the solvent in the extraction phase to concentrate and enrich the extracted substance. The ice setting temperature, pressure, and rotation speed are appropriately set to avoid loss or decomposition.

8. The method of claim 1, wherein the organic solvent is selected from the group consisting of methanol, ethanol, isopropanol, acetonitrile, acetone, methyl ethyl ketone, dimethylformamide, dimethylsulfoxide, and mixtures thereof. The volume ratio of the extractant to the original solution is 1:1-1:

5.

9. The method according to claim 1 or 2, wherein the organic solvent is methanol. ​

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