Method for quantitatively characterizing adsorption quantity of carboxylate and hydroximic acid medicament on surface of mineral

Abstract

The invention discloses a method for quantitatively characterizing the adsorption capacity of carboxylate and hydroximic acid on the surface of a mineral, and belongs to the technical field of mineral flotation separation and detection. The invention aims to provide a method which is simple to operate and good in test repeatability, and solves the problem that the adsorption quantity of each reagent after the carboxylate and hydroximic acid combined reagent is used cannot be quantitatively represented in the current mineral flotation separation. The method mainly comprises the following steps: (1) preparing a mineral sample and a combined reagent; (2) interacting the medicament with the mineral; (3) preparing a sample to be detected; (4) establishing a measurement method; and (5) quantitatively characterizing the adsorption capacity of the medicament. According to the quantitative characterization method provided by the invention, the defect that the adsorption capacity of the mineral, the carboxylate and the hydroximic acid combined medicament cannot be quantitatively characterized after the mineral acts is overcome.

Description

Technical Field

[0001] The present invention provides a method for quantitatively characterizing the adsorption amounts of each agent after the combined agents of carboxylate and hydroxamic acid are adsorbed on the mineral surface, belonging to the technical field of mineral flotation separation and detection. Background Technique

[0002] The flotation separation of minerals includes two main parts. One is the selective adsorption of agents on the mineral surface to form an adsorption layer; the other is the combination of bubbles and the minerals after adsorbing the agents and then floating up. Therefore, the agents play an important role in the flotation separation of minerals. Studying the interaction between the agents and minerals is an important way to reveal the flotation separation of minerals.

[0003] In the flotation separation of minerals, combined agents are usually used to achieve the selective separation of two or more minerals. The use of combined agents enhances the collecting property or selectivity of the agents. Therefore, in order to better obtain the influence of different agents on the flotation separation effect, researchers have carried out a lot of work and proposed a series of analysis methods.

[0004] The analysis methods for the flotation separation effect of combined agents in the flotation separation of minerals mainly include the following several kinds:

[0005] 1. Flotation test

[0006] Laboratory flotation test: Evaluate the influence of agents on the flotation effect of minerals through small-scale tests. Common equipment includes flotation machines and flotation columns.

[0007] Industrial flotation test: Test the performance of agents in the actual production environment and evaluate their industrial applicability.

[0008] 2. Surface analysis techniques

[0009] X-ray photoelectron spectroscopy (XPS): Analyze the chemical composition of the mineral surface, the agent adsorption situation and the chemical bond changes.

[0010] Fourier transform infrared spectroscopy (FTIR): Detect the adsorption behavior of agents on the mineral surface.

[0011] Atomic force microscope (AFM): Observe the mineral surface morphology and the agent adsorption layer.

[0012] 3. Electrochemical analysis

[0013] Potentiometric titration: Determine the surface potential of minerals and evaluate the influence of agents on the surface electric property.

[0014] Electrochemical impedance spectroscopy (EIS): Study the influence of agents on the electrochemical behavior of the mineral surface.

[0015] 4. Adsorption amount determination

[0016] Ultraviolet-Visible Spectroscopy (UV-Vis): The adsorption capacity is determined by the change in the concentration of the reagent in the solution.

[0017] Radioisotope Labeling Method: The reagent is labeled with a radioisotope to determine the adsorption capacity.

[0018] 5. Particle Analysis

[0019] Laser Particle Size Analysis: Evaluate the effect of the reagent on the particle size distribution of minerals.

[0020] Zeta Potential Analysis: Measure the surface potential of particles and evaluate the effect of the reagent on particle dispersion and aggregation.

[0021] 6. Flotation Foam Analysis

[0022] Foam Image Analysis: Analyze the foam structure and stability through image processing technology.

[0023] Foam Stability Test: Evaluate the effect of the reagent on foam stability.

[0024] 7. Computational Simulation

[0025] Molecular Dynamics Simulation: Simulate the adsorption behavior of the reagent on the mineral surface.

[0026] Density Functional Theory (DFT) Calculation: Study the interaction mechanism between the reagent and the mineral surface.

[0027] 8. On-line Detection Technology

[0028] On-line pH and Potential Detection: Real-time monitor the changes in pH and potential during the flotation process.

[0029] On-line Foam Analysis: Real-time monitor the foam characteristics and optimize the flotation conditions.

[0030] 9. Chemical Analysis

[0031] High Performance Liquid Chromatography (HPLC): Analyze the reagent concentration and its degradation products.

[0032] Gas Chromatography-Mass Spectrometry (GC-MS): Detect the reagent components and their changes.

[0033] 10. Mineral Liberation Analysis

[0034] Scanning Electron Microscope (SEM): Observe the mineral liberation degree and the effect of the reagent on liberation.

[0035] Mineral Liberation Analysis Software: Evaluate the mineral liberation degree through image analysis.

[0036] Among the numerous flotation separation effect analysis methods mentioned above, the methods that can quantitatively characterize the adsorption amounts of various reagents after the interaction between minerals and combined reagents have not received sufficient attention. Currently, the adsorption amounts of reagents on the mineral surface are mainly measured by ultraviolet spectrophotometer and TOC. However, the existing methods are all for the interaction between single reagent and minerals, and do not involve the quantitative characterization of the adsorption amounts of various reagents after the interaction of two or more reagents on the mineral surface. If the respective adsorption amounts of the corresponding combined reagents on the mineral surface after flotation separation can be accurately quantified, the interaction intensity of the combined reagents on the mineral surface will be further quantified, and the adsorption mechanism of the reagents on the mineral surface will be deeply analyzed, which is helpful to promote the selective separation of refractory minerals and improve the mineral utilization rate.

[0037] The existing methods for testing adsorption amounts are less effective for combined reagents. The main reasons are as follows: First, if an ultraviolet spectrophotometer is used to quantitatively characterize the adsorption amounts of various reagents on the mineral surface when two or more reagents are combined, it is required that the absorption peaks of the reagents do not overlap at all at the same absorption wavelength, so as to ensure that the reagents do not affect each other during the test. For combined reagents with overlapping absorption peaks, this method cannot be used for the quantitative characterization of adsorption amounts. Second, TOC obtains the reagent concentration by measuring the organic carbon or nitrogen in the solution (an additional module is required). If TOC is used to measure the adsorption amounts of various reagents on the mineral surface when two or more reagents are combined, it is required that the reagents used need to have their own special "markings" (mostly nitrogen elements) to distinguish them from other reagents. However, this type of method has strict restrictions on the types of flotation reagents and cannot be used for combined reagents of carboxylates and hydroxamic acids.

[0038] For example, for reagents that contain carbon element but do not contain nitrogen element, it is almost impossible to measure the adsorption amounts of various reagents. Similarly, for reagents that contain both carbon element and nitrogen element, the adsorption amounts of various reagents cannot be measured either. TOC can only measure the concentrations of various reagents under the condition that one reagent contains carbon element but does not contain nitrogen element, and the other reagent contains both carbon element and nitrogen element. And the TOC measurement method is easily interfered by external carbon elements and has high requirements for sample preparation and testing. Therefore, the current analysis methods cannot quantitatively characterize the adsorption amounts of combined reagents of carboxylates and hydroxamic acids on the mineral surface, and the adsorption separation effect of this type of combined reagent cannot be accurately detected yet.

[0039] Therefore, there is an urgent need to develop a combined reagent adsorption amount quantitative characterization method that is simple to operate, less affected by environmental factors, can quantitatively characterize the adsorption amounts of combined reagents of carboxylates and hydroxamic acids on the mineral surface, and has high feasibility and good accuracy. Summary of the Invention

[0040] Aiming at the technical defect in the prior art that the adsorption amount of the combined agent of carboxylate and hydroxamic acid on the mineral surface cannot be quantitatively characterized, the present invention aims to provide a method for quantitatively characterizing the adsorption amount of each agent after the combined agent of carboxylate and hydroxamic acid is adsorbed on the mineral surface. The technical object of the present invention is to provide a rapid, efficient, simple and convenient analysis method, which can separate and detect each component agent in the combined agent of carboxylate and hydroxamic acid, and realize the accurate quantitative characterization of the adsorption amount of each agent in this kind of combined agent.

[0041] In order to achieve the above technical object, the technical solution adopted by the present invention is as follows:

[0042] The present invention provides a method for quantitatively characterizing the adsorption amount of each agent after the combined agent of carboxylate and hydroxamic acid is adsorbed on the mineral surface, including the following steps:

[0043] (1) After the mineral is crushed and ground, it is reacted with the combined agent of carboxylate and hydroxamic acid. The obtained solid-liquid suspension is centrifuged and the supernatant is taken to obtain a sample to be tested;

[0044] (2) The sample to be tested obtained in step (1) is used to establish a standard curve of peak area and agent concentration by liquid chromatography. The mobile phase A used in the liquid chromatography is 0.05% phosphoric acid or water, the mobile phase B is acetonitrile, the flow rate of the mobile phase is 1 mL / min, the elution method is gradient elution, and the gradient elution method is as follows: 0-5 min, the proportion of mobile phase A is 30-55%, and the proportion of mobile phase B is 70-45%; 6-21 min, the proportion of mobile phase A is 70-90%, and the proportion of mobile phase B is 30-10%; 22-25 min, the proportion of mobile phase A is 30-55%, and the proportion of mobile phase B is 70-45%; then the concentrations of carboxylate and hydroxamic acid in the sample to be tested are obtained by conversion according to the standard curve;

[0045] (3) The adsorption amount of the agent on the mineral surface is quantitatively characterized by the residual concentration method.

[0046] The present invention provides a method for quantitatively characterizing the adsorption amount of each agent after the combined agent of carboxylate and hydroxamic acid is adsorbed on the mineral surface. This method is to make the combined agent interact with the mineral, obtain the sample to be tested by centrifugation, analyze the sample to be tested by liquid chromatography, and finally obtain the adsorption concentration of each agent through the concentration standard curve to quantitatively characterize the adsorption amount of the combined agent.

[0047] The above method provided by the present invention has the advantages of high resolution, high sensitivity, high selectivity, simple sample treatment, wide flexibility and applicability. Even at the same detection wavelength, the retention times of different substances are different. Therefore, different agents in the combined agent can be separated first and then the concentration can be detected, and it is less affected by external environmental factors. Based on this, the present invention establishes a concentration standard curve of a single agent by using liquid chromatography, and then analyzes the sample to be tested, so as to calculate the adsorption concentration of each agent in the combined agent and quantitatively characterize the adsorption amount, which will make up for the deficiency that the adsorption amount of the combined agent on the mineral surface cannot be quantitatively characterized at present and promote the further in-depth study of the basic research in the field of mineral flotation separation.

[0048] As shown in the comparative example of the present invention, when the elution method is replaced with isocratic elution, or the mobile phase and elution process of gradient elution are replaced, the combined agent cannot be well separated, and the adsorption amount after its flotation cannot be accurately quantified.

[0049] Furthermore, in step (1), the mineral is crushed and ground to a particle size of less than 0.15 mm.

[0050] Furthermore, in step (1), the carboxylate is any one of sodium acetate, sodium propionate, sodium oleate, sodium stearate and sodium benzoate.

[0051] Furthermore, in step (1), the hydroxamic acid is any one of benzohydroxamic acid, salicylhydroxamic acid, phenylsulfonylhydroxamic acid, octylhydroxamic acid and 1-naphthohydroxamic acid.

[0052] Furthermore, in step (1), the action time of the mineral and the combined agent is 3 min.

[0053] Furthermore, in step (1), the rotation speed of the centrifugal separation is 9000 - 10000 r / min, the centrifugal separation time is 15 min, and the number of centrifugal separation times is at least 2 times.

[0054] Furthermore, in step (2), the chromatographic column used in the liquid chromatography method is a C18 column, and the column temperature is 25°C.

[0055] Furthermore, in step (2), the injection volume each time is 50 - 100 μL.

[0056] Furthermore, in step (1), a pH adjuster is used to adjust the pH of the pulp, and the pH adjuster is NaOH and HCl.

[0057] The following examples are the specific implementation steps of the analysis method of the present invention:

[0058] 1. Weigh a certain amount of mineral, prepare carboxylate and hydroxamic acid single agents with a certain concentration, and mix the two agents according to the required ratio;

[0059] 2. Mix the prepared combined reagent with a certain amount of weighed mineral and let it act for a certain period of time;

[0060] 3. Put the solid-liquid suspension after the action into a centrifuge for centrifugal separation to obtain the supernatant, which is the sample to be measured;

[0061] 4. Establish a liquid chromatography operation method;

[0062] 5. Calculate the respective adsorption amounts of the two reagents, carboxylate and hydroxamic acid, on the mineral surface by the residual concentration method.

[0063] Among them, the respective adsorption amounts of the two reagents, carboxylate and hydroxamic acid, on the mineral surface are calculated by the following formula:

[0064] Among them, Γ is the adsorption amount of carboxylate or hydroxamic acid on the mineral surface, mol / g; C0 is the initial concentration of carboxylate or hydroxamic acid, mol / L; C1 is the concentration of carboxylate or hydroxamic acid in the supernatant, mol / L; m is the mass of the mineral, g; V is the volume of the liquid, L.

[0065] Compared with the prior art, the present invention has the following beneficial effects:

[0066] The present invention discloses a method for quantitatively characterizing the adsorption amounts of each reagent after the combined reagent of carboxylate and hydroxamic acid is adsorbed on the mineral surface. This method makes up for the technical defect that the adsorption amounts of each reagent after the combined reagent of carboxylate and hydroxamic acid is adsorbed on the mineral surface cannot be quantitatively characterized in the current mineral flotation separation field, and provides a new idea for in-depth analysis of the interaction mechanism between the combined reagent and the mineral in the mineral flotation separation field. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 It is the retention time and peak area diagram of sodium oleate and octyl hydroxamic acid at 0.2 mM respectively in Example 1 of the present invention;

[0068] Figure 2 It is the concentration and peak area standard curve of sodium oleate and octyl hydroxamic acid in Example 2 of the present invention;

[0069] Figure 3 It is the retention time and peak area diagram of sodium oleate at 0.18 mM and octyl hydroxamic acid at 0.12 mM in Example 3 of the present invention.

[0070] Figure 4 It is the liquid chromatography diagram of the combined reagent when the liquid chromatography method in Comparative Example 1 of the present invention is isocratic elution.

[0071] Figure 5 It is the liquid chromatography diagram of the combined reagent when the treatment method of the sample to be measured in Comparative Example 2 of the present invention is rotary evaporation and concentration.

[0072] Figure 6 When the liquid chromatography method of Comparative Example 3 of the present invention is isocratic elution, the combined agent liquid chromatography diagram when mobile phase A accounts for 15% and mobile phase B accounts for 85%.

[0073] Figure 7 When the liquid chromatography method of Comparative Example 4 of the present invention is isocratic elution, the combined agent liquid chromatography diagram when mobile phase A accounts for 30% and mobile phase B accounts for 70%.

[0074] Figure 8 When the liquid chromatography method of Comparative Example 5 of the present invention is isocratic elution, after replacing mobile phase A with pure water, the combined agent liquid chromatography diagram when mobile phase A accounts for 30% and mobile phase B accounts for 70%.

[0075] Figure 9 When the liquid chromatography method of Comparative Example 6 of the present invention is gradient elution, after replacing mobile phase A with pure water, the combined agent liquid chromatography diagram.

[0076] Figure 10 When the liquid chromatography method of Comparative Example 7 of the present invention is gradient elution, after replacing mobile phase A with methanol, the combined agent liquid chromatography diagram. Detailed implementation manners

[0077] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be specifically described below in combination with embodiments. It is necessary to point out that the following embodiments are only used to explain and illustrate the present invention and are not used to limit the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above-mentioned invention content still fall within the protection scope of the present invention.

[0078] Example 1

[0079] Prepare a combined agent and use liquid chromatography to detect the retention time and peak area. The method steps are as follows:

[0080] (1) Prepare sodium oleate and octyl hydroxamic acid solutions with a concentration of 4 mM respectively. Mix the two agents in a volume ratio of 1:1 to obtain a combined agent. Measure 36 mL of ultrapure water and add 4 mL of the combined agent to obtain a combined agent with sodium oleate and octyl hydroxamic acid concentrations of 0.2 mM respectively.

[0081] (2) Set the liquid chromatography method: select C18 column, column temperature 25°C, mobile phase A is 0.05% phosphoric acid, mobile phase B is acetonitrile, flow rate 1 mL / min, single injection volume 50 μL; the elution method is gradient elution: from 0 to 5 min, the proportion of mobile phase A is 55% and the proportion of mobile phase B is 45%; from 6 min to 21 min, the proportion of mobile phase A is 90% and the proportion of mobile phase B is 10%; from 22 min to 25 min, the proportion of mobile phase A is 55% and the proportion of mobile phase B is 45%.

[0082] Example 2

[0083] Prepare the combined reagent and use liquid chromatography to detect the retention time and peak area. The method steps are as follows:

[0084] (1) Prepare the sodium oleate and octyl hydroxamic acid solutions with a concentration of 4 mM respectively. Mix the two reagents according to a volume ratio of 3:1 to obtain the combined reagent, and prepare 40 mL of standard samples with different reagent concentrations respectively;

[0085] (2) Set the liquid chromatography method: select C18 column, column temperature 25°C, mobile phase A is 0.05% phosphoric acid, mobile phase B is acetonitrile, flow rate 1 mL / min, single injection volume 50 μL; from 0 to 5 min, the proportion of mobile phase A is 55% and the proportion of mobile phase B is 45%; from 6 min to 21 min, the proportion of mobile phase A is 90% and the proportion of mobile phase B is 10%; from 22 min to 25 min, the proportion of mobile phase A is 55% and the proportion of mobile phase B is 45%.

[0086] Example 3

[0087] A method for quantitatively characterizing the adsorption amounts of each reagent after the adsorption of the combined reagent of carboxylate and hydroxamic acid on the mineral surface, including the following steps:

[0088] (1) Prepare the sodium oleate and octyl hydroxamic acid solutions with a concentration of 4 mM respectively. Mix the two reagents according to a volume ratio of 2:3 to obtain the combined reagent;

[0089] (2) Weigh 2.0 g of bastnasite, measure 36 mL of ultrapure water, put the bastnasite and ultrapure water together in a flotation cell, set the stirring speed to 1992 r / min, first condition the pulp for 1 min, then adjust the pH value of the pulp to 10 with NaOH and HCl solutions, act for 3 min, then add 3 mL of the combined reagent, act for 3 min to obtain a solid-liquid suspension. Place the obtained suspension in a centrifuge for centrifugal separation. Set the centrifuge speed to 9500 r / min and the time to 15 min, then centrifuge the supernatant again, let it stand for a while and take the middle liquid as the sample to be measured;

[0090] (3) Set the liquid chromatography method to select C18 for the chromatographic column, the column temperature is 25 °C, mobile phase A is 0.05% phosphoric acid, mobile phase B is acetonitrile, the flow rate is 1 mL / min, and the single injection volume is 50 μL; from 0 to 5 min, the proportion of mobile phase A is 55%, and the proportion of mobile phase B is 45%; from 6 min to 21 min, the proportion of mobile phase A is 90%, and the proportion of mobile phase B is 10%; from 22 min to 25 min, the proportion of mobile phase A is 55%, and the proportion of mobile phase B is 45%.

[0091] Perform data processing on the liquid chromatography diagram. The corresponding peak area of sodium oleate is 0.65351, and the corresponding peak area of octyl hydroxamic acid is 7.13512. By converting through the standard curve, the concentration of sodium oleate in the supernatant is 0.13643 mM, and the concentration of octyl hydroxamic acid is 0.09257 mM at this time.

[0092] According to the calculation formula of the adsorption amount, the adsorption amount of sodium oleate in the composite reagent on the surface of bastnasite is The adsorption amount of octyl hydroxamic acid on the surface of bastnasite is:

[0093]

[0094] Example 4

[0095] Refer to the method of Example 3, where the stirring speed of centrifugal separation is set between 9000 - 10000 r / min, the number of centrifugal separations can be 3 or 4 times, and the injection volume each time is 50 - 100 μL. In gradient elution: from 0 to 5 min, the proportion of mobile phase A is 30 - 55%, and the proportion of mobile phase B is 70 - 45%; from 6 - 21 min, the proportion of mobile phase A is 70 - 90%, and the proportion of mobile phase B is 30 - 10%; from 22 - 25 min, the proportion of mobile phase A is 30 - 55%, and the proportion of mobile phase B is 70 - 45%.

[0096] Within the above parameter range, the obtained experimental results are similar to those of Example 3, and both can well separate and accurately quantify the adsorption amounts of each reagent after the composite reagent is adsorbed on the mineral surface.

[0097] Comparative Example 1

[0098] 1. Prepare solutions of sodium oleate and octyl hydroxamic acid with a concentration of 4 mM respectively. Mix the two reagents in a volume ratio of 1:1 to obtain a composite reagent. Measure 36 mL of ultrapure water and add 4 mL of the composite reagent to obtain a composite reagent with concentrations of sodium oleate and octyl hydroxamic acid of 0.2 mM respectively.

[0099] 2. Set the liquid chromatography method. Select C18 for the chromatographic column, the column temperature is 25°C, mobile phase A is 0.05% phosphoric acid, mobile phase B is acetonitrile, the flow rate is 1 mL / min, and the injection volume per time is 20 μL; the elution method is isocratic elution: the proportion of mobile phase A is 55%, and the proportion of mobile phase B is 45%.

[0100] It can be seen from the liquid chromatography diagram that under the isocratic elution conditions, only octyl hydroxamic acid can be detected, and sodium oleate cannot be detected. In this case, the adsorption amounts of each agent after the combined agent is adsorbed on the mineral surface cannot be accurately quantified.

[0101] Comparative Example 2

[0102] 1. Prepare sodium oleate and octyl hydroxamic acid solutions with a concentration of 4 mM respectively. Mix the two agents according to a volume ratio of 2:3 to obtain a combined agent. Measure 37 mL of ultrapure water and add 3 mL of the combined agent to obtain a combined agent with a sodium oleate concentration of 0.18 mM and an octyl hydroxamic acid concentration of 0.12 mM.

[0103] 2. Concentrate the sample to be tested to 1 mL by a rotary evaporator, and then perform liquid chromatography testing.

[0104] 3. Set the liquid chromatography method. Select C18 for the chromatographic column, the column temperature is 25°C, mobile phase A is 0.05% phosphoric acid, mobile phase B is acetonitrile, the flow rate is 1 mL / min, and the injection volume per time is 50 μL; from 0 to 5 min, the proportion of mobile phase A is 55%, and the proportion of mobile phase B is 45%; from 6 min to 21 min, the proportion of mobile phase A is 90%, and the proportion of mobile phase B is 10%; from 22 min to 25 min, the proportion of mobile phase A is 55%, and the proportion of mobile phase B is 45%.

[0105] It can be seen from the liquid chromatography diagram that the number of peaks in the peak area retention diagram increases at this time, indicating that the substance has changed after heating and concentration, and the substance corresponding to each peak cannot be distinguished. Therefore, the method of heating and concentration cannot be used to increase the concentration of the combined agent in the sample to be tested during the preparation process.

[0106] Comparative Example 3

[0107] 1. Prepare sodium oleate and octyl hydroxamic acid solutions with a concentration of 4 mM respectively. Mix the two agents according to a volume ratio of 1:1 to obtain a combined agent. Measure 36 mL of ultrapure water and add 4 mL of the combined agent to obtain a combined agent with sodium oleate and octyl hydroxamic acid concentrations of 0.2 mM respectively.

[0108] 2. Set the liquid chromatography method. Select C18 for the chromatographic column, the column temperature is 25°C, mobile phase A is 0.05% phosphoric acid, mobile phase B is acetonitrile, the flow rate is 1 mL / min, and the injection volume per time is 20 μL; the elution method is isocratic elution: the proportion of mobile phase A is 15%, and the proportion of mobile phase B is 85%.

[0109] As can be seen from the liquid chromatography diagram, although octyl hydroxamic acid and sodium oleate can be detected under these conditions, the peak shape of octyl hydroxamic acid is poor and there are many split peaks. In this case, it cannot be shown that this peak is only octyl hydroxamic acid, which does not meet the analysis requirements of the liquid chromatography diagram.

[0110] Comparative Example 4

[0111] 1. Prepare solutions of sodium oleate and octyl hydroxamic acid with a concentration of 4 mM respectively. Mix the two agents in a volume ratio of 1:1 to obtain a combined agent. Measure 36 mL of ultrapure water and add 4 mL of the combined agent to obtain a combined agent with concentrations of sodium oleate and octyl hydroxamic acid of 0.2 mM respectively.

[0112] 2. Set the liquid chromatography method as follows: select a C18 chromatographic column, column temperature 25 °C, mobile phase A is 0.05% phosphoric acid, mobile phase B is acetonitrile, flow rate 1 mL / min, single injection volume 20 μL; the elution method is isocratic elution: the proportion of mobile phase A is 30%, and the proportion of mobile phase B is 70%.

[0113] As can be seen from the liquid chromatography diagram, after increasing mobile phase A, the peak shape of octyl hydroxamic acid is slightly better, and the peak shape of sodium oleate becomes further better. However, there are still many split peaks for octyl hydroxamic acid. In this case, it cannot be shown that this peak is only octyl hydroxamic acid, so it does not meet the analysis requirements of the liquid chromatography diagram.

[0114] Comparative Example 5

[0115] 1. Prepare solutions of sodium oleate and octyl hydroxamic acid with a concentration of 4 mM respectively. Mix the two agents in a volume ratio of 1:1 to obtain a combined agent. Measure 36 mL of ultrapure water and add 4 mL of the combined agent to obtain a combined agent with concentrations of sodium oleate and octyl hydroxamic acid of 0.2 mM respectively.

[0116] 2. Set the liquid chromatography method as follows: select a C18 chromatographic column, column temperature 25 °C, mobile phase A is 0.05% phosphoric acid, mobile phase B is acetonitrile, flow rate 1 mL / min, single injection volume 50 μL; mobile phase A is changed to pure water, mobile phase B is still acetonitrile, and the elution method is isocratic elution: the proportion of mobile phase A is 30%, and the proportion of mobile phase B is 70%.

[0117] As can be seen from the liquid chromatography diagram, after changing mobile phase A to pure water, only one obvious peak is shown as octyl hydroxamic acid, but the peak shape of this peak is poor.

[0118] Comparative Example 6

[0119] 1. Prepare solutions of sodium oleate and octyl hydroxamic acid with a concentration of 4 mM respectively. Mix the two agents in a volume ratio of 1:1 to obtain a combined agent. Measure 36 mL of ultrapure water and add 4 mL of the combined agent to obtain a combined agent with concentrations of sodium oleate and octyl hydroxamic acid of 0.2 mM respectively.

[0120] 2. Set the liquid chromatography method. Select C18 for the chromatographic column, column temperature 25°C, flow rate 1 mL / min, and single injection volume 50 μL; change mobile phase A to pure water, mobile phase B remains acetonitrile, and the elution method is gradient elution: from 0 to 5 min, the proportion of mobile phase A is 55%, and the proportion of mobile phase B is 45%; from 6 min to 21 min, the proportion of mobile phase A is 90%, and the proportion of mobile phase B is 10%; from 22 min to 25 min, the proportion of mobile phase A is 55%, and the proportion of mobile phase B is 45%.

[0121] It can be seen from the liquid chromatography diagram that after changing mobile phase A to pure water, although the peaks of octyl hydroxamic acid and sodium oleate are shown, the solvent peak is significant at this time, which is not conducive to the detection of subsequent low-concentration samples.

[0122] Comparative Example 7

[0123] 1. Prepare sodium oleate and octyl hydroxamic acid solutions with a concentration of 4 mM respectively. Mix the two agents according to a volume ratio of 1:1 to obtain a combined agent. Measure 36 mL of ultrapure water and add 4 mL of the combined agent to obtain a combined agent with sodium oleate and octyl hydroxamic acid concentrations of 0.2 mM respectively.

[0124] 2. Set the liquid chromatography method. Select C18 for the chromatographic column, column temperature 25°C, flow rate 1 mL / min, and single injection volume 50 μL; change mobile phase A to methanol, mobile phase B remains acetonitrile, and the elution method is gradient elution: from 0 to 5 min, the proportion of mobile phase A is 55%, and the proportion of mobile phase B is 45%; from 6 min to 21 min, the proportion of mobile phase A is 90%, and the proportion of mobile phase B is 10%; from 22 min to 25 min, the proportion of mobile phase A is 55%, and the proportion of mobile phase B is 45%.

[0125] It can be seen from the liquid chromatography diagram that after changing mobile phase A to methanol, the liquid phase peak shape changes greatly and fluctuates, and cannot provide accurate and reliable information.

Claims

1. A method for quantitatively characterizing the amount of each agent adsorbed after a combination of carboxylate and hydroxamic acid is adsorbed on a mineral surface, characterized in that: The following steps are involved: (1) After the mineral is crushed and ground, it is reacted with a combination of carboxylate and hydroxamic acid, and the resulting solid-liquid suspension is centrifuged and the supernatant is collected to obtain a sample to be tested; (2) using the sample obtained in step (1) to establish a standard curve of peak area and drug concentration by liquid chromatography, wherein the mobile phase A used in the liquid chromatography is 0.05% phosphoric acid, the mobile phase B is acetonitrile, and the elution method is gradient elution; and then converting the carboxylate and hydroxamic acid concentrations in the sample to be tested according to the standard curve; (3) The residual concentration method is used to quantitatively characterize the adsorption amount of the agent on the mineral surface.

2. The method for quantitatively characterizing the adsorption amount of each agent after the combination of carboxylate and hydroxamic acid is adsorbed on the surface of a mineral according to claim 1, characterized in that: The gradient elution method in step (2) is: 0-5min, mobile phase A accounts for 30-55%, and mobile phase B accounts for 70-45%; 6-21min, mobile phase A accounts for 70-90%, and mobile phase B accounts for 30-10%; 22-25min, mobile phase A accounts for 30-55%, and mobile phase B accounts for 70-45%.

3. The method for quantitatively characterizing the adsorption amount of each agent after the combination of carboxylate and hydroxamic acid is adsorbed on the mineral surface according to claim 1 or 2, characterized in that: The flow rate of the mobile phase was 1 mL / min.

4. The method for quantitatively characterizing the adsorption amount of each agent after the combination of carboxylate and hydroxamic acid is adsorbed on the surface of a mineral according to claim 1 or 2, characterized in that: The injection volume in each step (2) is 50-100 μL.

5. The method for quantitatively characterizing the adsorption amount of each agent after the combination of carboxylate and hydroxamic acid is adsorbed on the surface of a mineral according to claim 1 or 2, characterized in that: In step (1), the mineral is crushed and ground to a particle size of less than 0.15 mm.

6. The method for quantitatively characterizing the adsorption amount of each agent after the combination of carboxylate and hydroxamic acid is adsorbed on the surface of a mineral according to claim 1 or 2, characterized in that: The carboxylate is any one of sodium acetate, sodium propionate, sodium oleate, sodium stearate and sodium benzoate; the hydroxamic acid is any one of benzohydroxamic acid, salicylic hydroxamic acid, benzenesulfonyl hydroxamic acid, octyl hydroxamic acid and 1-naphthohydroxamic acid.

7. The method for quantitatively characterizing the adsorption amount of each agent after the combination of carboxylate and hydroxamic acid is adsorbed on the surface of a mineral according to claim 1 or 2, characterized in that: In step (1), a pH adjuster is used to adjust the pH value of the slurry, and the pH adjuster is NaOH and HCl.

8. The method for quantitatively characterizing the adsorption amount of each agent after the combination of carboxylate and hydroxamic acid is adsorbed on the surface of a mineral according to claim 1 or 2, characterized in that: The action time of the mineral and the combined agent in step (1) is 3 minutes.

9. The method for quantitatively characterizing the adsorption amount of each agent after the combination of carboxylate and hydroxamic acid is adsorbed on the surface of a mineral according to claim 1 or 2, characterized in that: The centrifugal separation speed in step (1) is 9000-10000 r / min, the centrifugal separation time is 15 min, and the number of centrifugal separations is at least 2 times.

10. The method for quantitatively characterizing the adsorption amount of each agent after the combination of carboxylate and hydroxamic acid is adsorbed on the surface of a mineral according to claim 1 or 2, characterized in that: The chromatographic column used in the liquid chromatography method in step (2) is a C18 column, and the column temperature is 25°C.

Images