Detection method of sodium 3-chloro-2-hydroxypropyl sulfonate content and its application

Abstract

The present application embodiment proposes a detection method and use of 3-chloro-2-hydroxypropyl sodium sulfonate content. The detection method includes: under alkaline conditions, reacting different concentrations of 3-chloro-2-hydroxypropyl sodium sulfonate standard solutions with sodium 4-mercaptobenzoate in a water bath to obtain standard samples of different concentrations; performing high performance liquid chromatography ultraviolet detection on standard samples of different concentrations to obtain the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate in standard samples of different concentrations; and obtaining a linear equation of the corresponding relationship between concentration x and peak area y; performing high performance liquid chromatography ultraviolet detection on the sample to be tested to obtain the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate in the sample to be tested, and calculating the concentration of 3-chloro-2-hydroxypropyl sodium sulfonate in the sample to be tested; the detection method of the present application embodiment is not only easy to operate, but also can effectively improve the separation effect, detection accuracy and precision.

Description

Technical Field

[0001] The present application relates to the technical field of analytical chemistry, and in particular to a method for detecting the content of sodium 3-chloro-2-hydroxypropyl sulfonate and a use thereof. Background Art

[0002] Sodium 3-chloro-2-hydroxypropyl sulfonate (CHPS-Na) is an organic chemical intermediate and is often used to prepare a variety of products such as surfactants, modified starch or psychotropic drug APIs; among them, sodium 3-chloro-2-hydroxypropyl sulfonate is irritating to the skin and eyes.

[0003] At present, in the cocamidopropyl hydroxysulfonate synthesized by reacting sodium 3-chloro-2-hydroxypropyl sulfonate as a raw material with cocamidopropyl dimethyl tertiary amine, there will be a certain amount of sodium 3-chloro-2-hydroxypropyl sulfonate residue; because cocamidopropyl hydroxysulfonate acts directly on the human body as a cleaning agent or food additive, therefore, when sodium 3-chloro-2-hydroxypropyl sulfonate is used as a raw material to produce cocamidopropyl hydroxysulfonate, the residue in the product should be limited.

[0004] In the prior art, the detection method of residual 3-chloro-2-hydroxypropyl sodium sulfonate includes chemical method and instrumental method. Among them, the chemical method has cationic resin exchange acid-base titration and hydrolysis silver method, and the instrumental method has high performance liquid phase method and ion chromatography. In the detection of high performance liquid phase method, the detection wavelength of 3-chloro-2-hydroxypropyl sodium sulfonate is shorter, about 200nm, at this wavelength, almost all substances have response, and the interference is serious when the sample composition is complex, and it cannot be detected when the content is low by evaporative light scattering detector and differential detector. At the same time, due to the complex composition in cocamidopropyl hydroxysulfobetaine, it is required to have high personnel conditions when directly detecting by ion chromatography, and the operation is difficult. And 3-chloro-2-hydroxypropyl sodium sulfonate is a very water-soluble substance, it is difficult to purify in pre-treatment, and the retention time in the chromatographic column is very short, resulting in the inability to be effectively separated from impurities, thereby affecting the accuracy of the test results.

[0005] In view of this, the present application provides a method for detecting the content of sodium 3-chloro-2-hydroxypropyl sulfonate. Summary of the invention

[0006] The purpose of the embodiments of the present application is to provide a method for detecting the content of sodium 3-chloro-2-hydroxypropyl sulfonate and its use.

[0007] To achieve the above objectives, the present application proposes the following technical solutions:

[0008] In a first aspect, the present application embodiment provides a method for detecting the content of sodium 3-chloro-2-hydroxypropyl sulfonate, the detection method comprising:

[0009] Prepare standard solutions of 3-chloro-2-hydroxypropyl sodium sulfonate of different concentrations; react the standard solutions of 3-chloro-2-hydroxypropyl sodium sulfonate of different concentrations with sodium 4-mercaptobenzoate in a water bath under alkaline conditions to obtain standard samples of different concentrations;

[0010] Performing high performance liquid chromatography ultraviolet detection on standard samples of different concentrations to obtain the peak areas of sodium 3-chloro-2-hydroxypropyl sulfonate in the standard samples of different concentrations; obtaining a linear equation of the corresponding relationship between concentration x and peak area y based on the peak areas corresponding to the standard samples of different concentrations;

[0011] A cocamidopropyl hydroxysulfobetaine solution is prepared; under alkaline conditions, the cocamidopropyl hydroxysulfobetaine solution is reacted with sodium 4-mercaptobenzoate in a water bath to obtain a sample to be tested;

[0012] The sample to be tested is subjected to high performance liquid chromatography ultraviolet detection to obtain the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate in the sample to be tested; the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate in the sample to be tested is substituted into a linear equation to calculate the concentration of 3-chloro-2-hydroxypropyl sodium sulfonate in the sample to be tested.

[0013] As an embodiment, under alkaline conditions, different concentrations of sodium 3-chloro-2-hydroxypropyl sulfonate standard solutions are reacted with sodium 4-mercaptobenzoate in a water bath to obtain standard samples of different concentrations, including:

[0014] Add alkali reagent and sodium 4-mercaptobenzoate to standard solutions of sodium 3-chloro-2-hydroxypropyl sulfonate with different concentrations, and place them in a water bath at 70°C for reaction;

[0015] After the reaction, phosphoric acid and acetonitrile were added, the volume was fixed with distilled water, and bubbles were removed by ultrasonic wave. Standard samples of different concentrations were obtained after filtration.

[0016] As an embodiment, the method of preparing a cocamidopropyl hydroxysulfobetaine solution and reacting the cocamidopropyl hydroxysulfobetaine solution with sodium 4-mercaptobenzoate in a water bath under alkaline conditions to obtain a sample to be tested comprises:

[0017] Prepare a cocamidopropyl hydroxysulfobetaine solution, add an alkali reagent and sodium 4-mercaptobenzoate to the cocamidopropyl hydroxysulfobetaine solution, and place the solution in a 70°C water bath for reaction;

[0018] After the reaction, phosphoric acid and acetonitrile were added, the volume was fixed with distilled water, and bubbles were removed by ultrasonic wave. The sample to be tested was obtained after filtration.

[0019] As an embodiment, the alkaline agent is sodium carbonate.

[0020] As an implementation method, the linear equation is:

[0021] y=30.524x-2.868, correlation coefficient R 2 =0.9998.

[0022] As an embodiment, the chromatographic column used in the high performance liquid chromatography ultraviolet detection is Agilent SB-C8.

[0023] As an embodiment, the column temperature of the chromatographic column is 30°C.

[0024] As an embodiment, the chromatographic conditions of the high performance liquid chromatography ultraviolet detection include:

[0025] The detection wavelength was 250-260 nm, and the injection volume was 20 μL;

[0026] Mobile phase A was acetonitrile;

[0027] The mobile phase B was a mixed solution of acetonitrile, water and phosphoric acid in a volume ratio of 100:898:2.

[0028] As an embodiment, the gradient elution program of mobile phase A and mobile phase B is:

[0029] Elution was performed with mobile phase A and mobile phase B at a volume ratio of 0:100 for 7 min;

[0030] Elution was performed with mobile phase A and mobile phase B in a volume ratio of 80:20 for 5 min;

[0031] Elution was performed with mobile phase A and mobile phase B at a volume ratio of 0:100 for 5 min;

[0032] Among them, the flow rate is 1.0mL / min.

[0033] In a second aspect, the embodiments of the present application provide the use of the detection method described in the first aspect in the quality control of cocamidopropyl hydroxysulfobetaine products.

[0034] The embodiments of the present application have at least the following beneficial effects:

[0035] In the embodiment of the present application, sodium 4-mercaptobenzoate is used as a derivatization reagent. Under alkaline conditions, sodium 3-chloro-2-hydroxypropyl sulfonate and sodium 4-mercaptobenzoate undergo a nucleophilic substitution reaction in a water bath to generate sodium 3-(4-carboxymethylphenylthio)-2-hydroxypropyl sulfonate. Among them, sodium 3-(4-carboxymethylphenylthio)-2-hydroxypropyl sulfonate generated by derivatization is very easy to separate in high performance liquid chromatography, and can achieve the purpose of separation and detection through high performance liquid chromatography, so it is easy to eliminate the interference of matrix effect and improve the detection accuracy; therefore, the detection method of the embodiment of the present application is not only easy to operate, but also can effectively improve the separation effect, detection accuracy and precision.

[0036] The detection method provided in the embodiment of the present application can more accurately detect the content of 3-chloro-2-hydroxypropyl sodium sulfonate in cocamidopropyl hydroxysulfonate, and the detection method is highly efficient; thus, the embodiment of the present application solves the problem of impurity interference in the existing detection method of 3-chloro-2-hydroxypropyl sodium sulfonate, and has a better application prospect in the quality control of cocamidopropyl hydroxysulfonate.

[0037] Additional aspects and advantages of the present application will be partially given in the following description, which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the effect of the derivatization reaction temperature on the peak area of ​​sodium 3-chloro-2-hydroxypropyl sulfonate;

[0039] Figure 2 is the liquid chromatogram of 3-chloro-2-hydroxypropyl sodium sulfonate;

[0040] Figure 3 Schematic diagram of the linear equation between the concentration and peak area of ​​sodium 3-chloro-2-hydroxypropyl sulfonate. DETAILED DESCRIPTION

[0041] The technical scheme in the embodiments will be clearly and completely described below in combination with the embodiments of the present application and the accompanying drawings. Obviously, the embodiments described below are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0042] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0043] It should also be understood that the terms used in this specification of the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present application. As used in the specification of the embodiments of the present application and the appended claims, unless the context clearly indicates otherwise, the singular forms of "a", "an" and "the" are intended to include plural forms.

[0044] The following is a detailed description of the method for detecting the content of sodium 3-chloro-2-hydroxypropyl sulfonate in the examples of the present application and its use.

[0045] First, the detection method of this embodiment is described.

[0046] In the prior art, when 3-chloro-2-hydroxypropyl sodium sulfonate is detected by high performance liquid chromatography, since the detection wavelength of 3-chloro-2-hydroxypropyl sodium sulfonate is relatively short, at about 200 nm, at this wavelength, almost all substances respond, and interference is serious when the sample composition is complex; at the same time, 3-chloro-2-hydroxypropyl sodium sulfonate has good water solubility and a very short retention time in the chromatographic column, resulting in inability to be effectively separated from impurities, thereby affecting the accuracy of the detection result.

[0047] In view of this, this embodiment provides a method for detecting the content of sodium 3-chloro-2-hydroxypropyl sulfonate.

[0048] Specifically, the detection method comprises:

[0049] (1) preparing 3-chloro-2-hydroxypropyl sodium sulfonate standard solutions of different concentrations; reacting the 3-chloro-2-hydroxypropyl sodium sulfonate standard solutions of different concentrations with sodium 4-mercaptobenzoate in a water bath under alkaline conditions to obtain standard samples of different concentrations;

[0050] (2) performing high performance liquid chromatography ultraviolet detection on standard samples of different concentrations to obtain the peak areas of sodium 3-chloro-2-hydroxypropyl sulfonate in the standard samples of different concentrations; based on the peak areas corresponding to the standard samples of different concentrations, obtaining a linear equation for the corresponding relationship between concentration x and peak area y;

[0051] (3) preparing a cocamidopropyl hydroxysulfobetaine solution; reacting the cocamidopropyl hydroxysulfobetaine solution with sodium 4-mercaptobenzoate in a water bath under alkaline conditions to obtain a sample to be tested;

[0052] (4) performing high performance liquid chromatography ultraviolet detection on the sample to be tested to obtain the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate in the sample to be tested; substituting the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate in the sample to be tested into a linear equation to calculate the concentration of 3-chloro-2-hydroxypropyl sodium sulfonate in the sample to be tested.

[0053] It is understood that under alkaline conditions, sodium 3-chloro-2-hydroxypropyl sulfonate and sodium 4-mercaptobenzoate undergo a nucleophilic substitution reaction in a water bath to generate sodium 3-(4-carboxymethylphenylthio)-2-hydroxypropyl sulfonate. Among them, sodium 3-(4-carboxymethylphenylthio)-2-hydroxypropyl sulfonate generated by derivatization is very easy to separate in high performance liquid chromatography, and can achieve the purpose of separation and detection through high performance liquid chromatography, so it is easy to eliminate the interference of matrix effect and improve the detection accuracy.

[0054] Therefore, the detection method of the embodiment of the present application is not only easy to operate, but also can effectively improve the separation effect, detection accuracy and precision.

[0055] The CAS number of the 3-chloro-2-hydroxypropyl sodium sulfonate of the present embodiment is 126-83-0.

[0056] Next, the relevant steps of the above detection method will be further described.

[0057] Step (1), preparing 3-chloro-2-hydroxypropyl sodium sulfonate standard solutions of different concentrations; reacting 3-chloro-2-hydroxypropyl sodium sulfonate standard solutions of different concentrations with sodium 4-mercaptobenzoate in a water bath under alkaline conditions to obtain standard samples of different concentrations; may be:

[0058] Weigh 0.2008 g of sodium 3-chloro-2-hydroxypropyl sulfonate standard, dissolve it in distilled water, dilute to 100 mL, and shake well; use a pipette to transfer 10 mL into another 100 mL volumetric flask, dilute to volume, mix well, and obtain a stock solution.

[0059] In this embodiment, after obtaining the stock solution, different concentrations of 3-chloro-2-hydroxypropyl sodium sulfonate standard solutions can be prepared based on the stock solution, and an alkali reagent and sodium 4-mercaptobenzoate are added to the 3-chloro-2-hydroxypropyl sodium sulfonate standard solution, which is placed in a water bath for reaction to obtain standard samples of different concentrations.

[0060] It can be understood that the alkaline conditions described in this embodiment are pH values ​​greater than 7, and in this embodiment, an alkaline environment is created by adding an alkaline reagent, sodium carbonate.

[0061] Specifically, under alkaline conditions, different concentrations of sodium 3-chloro-2-hydroxypropyl sulfonate standard solutions are reacted with sodium 4-mercaptobenzoate in a water bath to obtain standard samples of different concentrations, including:

[0062] Alkaline reagent and sodium 4-mercaptobenzoate were added to standard solutions of sodium 3-chloro-2-hydroxypropyl sulfonate of different concentrations, respectively, and the solutions were placed in a 70°C water bath for reaction. After the reaction, phosphoric acid and acetonitrile were added, the solution was fixed to volume with distilled water, and bubbles were removed by ultrasonication. Standard samples of different concentrations were obtained after filtration.

[0063] For example, after the above stock solution (3-chloro-2-hydroxypropyl sodium sulfonate stock solution with a concentration of 200.8 mg / L) is prepared, 0.50 mL, 1.00 mL, 2.00 mL, 4.00 mL and 6.00 mL of the stock solution are respectively measured in 50 mL volumetric flasks, and the volume is filled up to 20 mL with distilled water, 0.5 mL of 5% sodium carbonate by mass concentration is added, and 0.5 mL of 1% sodium 4-mercaptobenzoate solution by mass concentration is added dropwise; the flasks are respectively placed in a water bath at 70° C. for 1-3 hours;

[0064] After the reaction, 0.5 mL of 10% phosphoric acid was added to terminate the reaction, 5 mL of acetonitrile was added, and the volume was adjusted to the mark with distilled water. The bubbles were removed by ultrasound, and a series of standard samples were obtained by filtering with a syringe filter.

[0065] Usually, the ultrasonication time is 3 to 5 minutes, preferably 5 minutes.

[0066] The sodium 4-mercaptobenzoate in this embodiment is added in the form of a sodium 4-mercaptobenzoate solution.

[0067] The preparation method of the sodium 4-mercaptobenzoate solution is as follows: weigh 0.5 g of sodium 4-mercaptobenzoate, add 10 g of acetonitrile and 39.5 g of water, and dissolve by ultrasonication to obtain a sodium 4-mercaptobenzoate solution with a mass concentration of 1%.

[0068] This embodiment found through relevant experiments that the peak area of ​​sodium 3-chloro-2-hydroxypropyl sulfonate increases with increasing temperature, and after reaching the peak value, it decreases with increasing temperature. When the temperature is 70°C, the peak area is the largest, and this temperature has a good derivation effect, which is conducive to reflecting the test results.

[0069] In step (1), in this embodiment, sodium 4-mercaptobenzoate is used as a derivatization reagent to cause a nucleophilic substitution reaction between sodium 3-chloro-2-hydroxypropyl sulfonate and sodium 4-mercaptobenzoate to generate sodium 3-(4-carboxymethylphenylthio)-2-hydroxypropyl sulfonate. The sodium 3-(4-carboxymethylphenylthio)-2-hydroxypropyl sulfonate generated by derivatization is very easy to separate in high performance liquid chromatography, and can achieve the purpose of separation and detection through high performance liquid chromatography, so it is easy to eliminate the interference of matrix effect and improve the detection accuracy and precision.

[0070] In step (2), after the standard samples of different concentrations are prepared, high performance liquid chromatography ultraviolet detection is performed on the standard samples of different concentrations to obtain the peak areas of sodium 3-chloro-2-hydroxypropyl sulfonate in the standard samples of different concentrations; and based on the peak areas corresponding to the standard samples of different concentrations, a linear equation of the corresponding relationship between the concentration x and the peak area y is obtained;

[0071] That is, linear regression is performed with the concentration of sodium 3-chloro-2-hydroxypropyl sulfonate as the abscissa x and the peak area as the ordinate y to obtain the corresponding linear equation.

[0072] Specifically, the above linear equation is: y=30.524x-2.868, and the correlation coefficient R 2 =0.9998.

[0073] In step (2), the standard sample after the derivatization reaction is separated and detected by high performance liquid chromatography ultraviolet; wherein the sodium 3-(4-carboxymethylphenylthio)-2-hydroxypropyl sulfonate generated by derivatization is very easy to separate in high performance liquid chromatography, and the purpose of separation and detection can be achieved by high performance liquid chromatography, so it is easy to eliminate the interference of matrix effect and improve the detection accuracy.

[0074] At the same time, in step (2), based on the above test results (peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate), a linear equation (calibration model) of the corresponding relationship between concentration x and peak area y can be obtained; based on the linear equation, when the content of the sample to be tested is tested, the content (concentration) of 3-chloro-2-hydroxypropyl sodium sulfonate in the cocamidopropyl hydroxysulfobetaine solution can be quickly calculated according to the peak area of ​​the sample to be tested.

[0075] It is understandable that the ultraviolet detection of the high performance liquid chromatography of this embodiment can be performed in a high performance liquid chromatograph, such as an Agilent 1260 liquid chromatograph.

[0076] In step (3), a cocamidopropyl hydroxysulfobetaine solution is prepared; under alkaline conditions, the cocamidopropyl hydroxysulfobetaine solution is reacted with sodium 4-mercaptobenzoate in a water bath to obtain a sample to be tested, comprising:

[0077] Prepare a cocamidopropyl hydroxysulfobetaine solution, add an alkali reagent and sodium 4-mercaptobenzoate to the cocamidopropyl hydroxysulfobetaine solution, and place the solution in a 70°C water bath for reaction;

[0078] After the reaction, phosphoric acid and acetonitrile were added, the volume was fixed with distilled water, and bubbles were removed by ultrasonic wave. The sample to be tested was obtained after filtration.

[0079] Specifically, the above steps may be:

[0080] Weigh 5 g (accurate to 1 mg) of cocamidopropyl hydroxysulfobetaine, place in a 50 mL volumetric flask, add 20 mL of distilled water, add 0.5 mL of 5% sodium carbonate, add 0.5 mL of 1% sodium 4-mercaptobenzoate dropwise, place in a 70°C water bath for 1-3 hours to carry out a derivatization reaction; after the reaction is completed, add 0.5 mL of 10% phosphoric acid solution to terminate the reaction, add 5 mL of acetonitrile, distilled water to 50 mL, remove bubbles by ultrasound, and filter with a syringe filter to obtain a sample to be tested.

[0081] As mentioned above, the alkaline conditions described in this embodiment are pH values ​​greater than 7. In this embodiment, an alkaline environment is created by adding an alkaline reagent, sodium carbonate.

[0082] Usually, the ultrasonication time is 3 to 5 minutes, preferably 5 minutes.

[0083] It can be understood that step (3) is to cause the 3-chloro-2-hydroxypropyl sodium sulfonate in the cocamidopropyl hydroxysulfobetaine solution to undergo a nucleophilic substitution reaction with sodium 4-mercaptobenzoate to generate 3-(4-carboxymethylphenylthio)-2-hydroxypropyl sodium sulfonate. The 3-(4-carboxymethylphenylthio)-2-hydroxypropyl sodium sulfonate generated by derivatization is very easy to separate in the subsequent high performance liquid chromatography, which can effectively eliminate the interference of the matrix effect and improve the accuracy of the test result.

[0084] In step (4), the sample to be tested is subjected to high performance liquid chromatography ultraviolet detection to obtain the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate in the sample to be tested; the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate in the sample to be tested is substituted into a linear equation to calculate the concentration of 3-chloro-2-hydroxypropyl sodium sulfonate in the sample to be tested, specifically comprising:

[0085] The sample to be tested obtained in step (3) is injected into a high performance liquid chromatograph for high performance liquid ultraviolet detection to obtain the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate; the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate obtained is substituted into the linear equation obtained in step (2) to calculate the concentration of 3-chloro-2-hydroxypropyl sodium sulfonate.

[0086] Therefore, in this embodiment, the sample to be tested after the above derivatization reaction is separated and detected by high performance liquid chromatography ultraviolet; the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate in the sample to be tested is obtained. At the same time, based on the linear equation (calibration model) obtained in step (2), the content of 3-chloro-2-hydroxypropyl sodium sulfonate in the cocamidopropyl hydroxysulfobetaine solution can be quickly obtained according to the peak area of ​​the sample to be tested.

[0087] Therefore, the testing scheme of this embodiment has better detection accuracy, and the testing process is more convenient and faster.

[0088] It is understandable that in the test processes in steps (2) and (4), the sample (standard sample or sample to be tested) is injected into a high performance liquid chromatograph for high performance liquid ultraviolet detection.

[0089] As an implementation mode, the chromatographic column used in the above-mentioned high performance liquid chromatography ultraviolet detection is Agilent SB-C8, and the column temperature of the chromatographic column is 30°C.

[0090] As an embodiment, the chromatographic conditions of the above-mentioned high performance liquid chromatography ultraviolet detection include:

[0091] The detection wavelength is 250-260 nm (e.g., 256 nm), and the injection volume is 20 μL;

[0092] Mobile phase A was acetonitrile;

[0093] The mobile phase B is a mixed solution of acetonitrile, water and phosphoric acid (such as phosphoric acid with a mass concentration of 85%) in a volume ratio of 100:898:2.

[0094] In this embodiment, the gradient elution program of mobile phase A and mobile phase B is:

[0095] Elution was performed with mobile phase A and mobile phase B at a volume ratio of 0:100 for 7 min;

[0096] Elution was performed with mobile phase A and mobile phase B in a volume ratio of 80:20 for 5 min;

[0097] Elution was performed with mobile phase A and mobile phase B at a volume ratio of 0:100 for 5 min;

[0098] Among them, the flow rate is 1.0mL / min.

[0099] In summary, in this embodiment, sodium 4-mercaptobenzoate is used as a derivatization reagent. Under alkaline conditions, sodium 3-chloro-2-hydroxypropyl sulfonate and sodium 4-mercaptobenzoate undergo a nucleophilic substitution reaction in a water bath to generate sodium 3-(4-carboxymethylphenylthio)-2-hydroxypropyl sulfonate. Among them, sodium 3-(4-carboxymethylphenylthio)-2-hydroxypropyl sulfonate generated by derivatization is very easy to separate in high performance liquid chromatography, and can achieve the purpose of separation and detection through high performance liquid chromatography, so it is easy to eliminate the interference of matrix effect and improve the detection accuracy; that is, the detection method of this embodiment is not only easy to operate, but also can effectively improve the separation effect, detection accuracy and precision.

[0100] Next, the use of the above detection method in the quality control of cocamidopropyl hydroxysultaine products will be described.

[0101] It is understandable that, since a certain amount of sodium 3-chloro-2-hydroxypropyl sulfonate will remain in the cationic cocamidopropyl hydroxysulfonate product produced using sodium 3-chloro-2-hydroxypropyl sulfonate as a raw material, and cationic cocamidopropyl hydroxysulfonate is usually used as a cleaning agent or food additive, it is easy for the residual sodium 3-chloro-2-hydroxypropyl sulfonate to be directly or indirectly contacted or ingested by the human body. Therefore, when sodium 3-chloro-2-hydroxypropyl sulfonate is used as a raw material to produce cocamidopropyl hydroxysulfonate, the residual amount in cocamidopropyl hydroxysulfonate should be limited.

[0102] As mentioned above, the detection method provided in this embodiment can detect the content of 3-chloro-2-hydroxypropyl sodium sulfonate in cocamidopropyl hydroxysulfonate more accurately and quickly, and the detection method is highly efficient; therefore, it can meet the needs of safety risk screening of 3-chloro-2-hydroxypropyl sodium sulfonate in cocamidopropyl hydroxysulfonate, and can provide good technical support for the quality control and safety monitoring of cocamidopropyl hydroxysulfonate, indicating that the detection method has better application prospects in the quality control of cocamidopropyl hydroxysulfonate.

[0103] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate / explain the present application and are not used to limit the scope of the present application.

[0104] In the following examples, the materials, reagents and instruments used can be purchased from commercial sources unless otherwise specified.

[0105] It should be noted that, in the following examples, unless otherwise specified, the method and conditions for analysis (separation and detection) using a high performance liquid chromatograph are as follows:

[0106] The preparation method of the sodium 4-mercaptobenzoate solution is as follows: weigh 0.5 g of sodium 4-mercaptobenzoate, add 10 g of acetonitrile and 39.5 of water, and dissolve by ultrasonication to obtain a sodium 4-mercaptobenzoate solution with a mass concentration of 1%.

[0107] Agilent 1260 liquid chromatograph was used for high performance liquid chromatography, and the concentration of phosphoric acid solution in mobile phase B was 85%.

[0108] Mobile phase A was acetonitrile; mobile phase B was acetonitrile: water: phosphoric acid = 100: 898: 2 (volume ratio).

[0109] The gradient elution program is shown in Table 1 below:

[0110] Table 1:

[0111] Time (min) Mobile phase A(%) Mobile phase B(%) Flow rate (mL / min) 0.00 0 100 1 7.00 0 100 1 8.00 80 20 1 13.00 80 20 1 14.00 0 100 1 19.00 0 100 1

[0112] Among them, the chromatographic column selected is Agilent ZORBAX SB-C8, the chromatographic column length is 250mm, the chromatographic column inner diameter is 4.6mm, and the chromatographic column filler particle diameter is 5μm; the detection wavelength is set to 256 nm, the column temperature is 30℃, and the injection volume is 20μL.

[0113] Embodiment 1-10:

[0114] This example found that the derivatization temperature of 3-chloro-2-hydroxypropyl sodium sulfonate affects its peak area. Therefore, by setting a gradient water bath temperature, the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate is detected, specifically:

[0115] Weigh 0.2001 g of sodium 3-chloro-2-hydroxypropyl sulfonate standard, dissolve it in distilled water, dilute to 100 mL, and shake well; use a pipette to transfer 10 mL to another 100 mL volumetric flask, dilute to volume, mix well, and obtain a stock solution with a concentration of 200.1 mg / L.

[0116] Take 10 50mL volumetric flasks, transfer 3mL of 200.1mg / L sodium 3-chloro-2-hydroxypropyl sulfonate stock solution into the volumetric flasks, fill them up to 20mL with distilled water, add 0.5mL of 5% sodium carbonate and 0.5mL of 1% sodium 4-mercaptobenzoate, mix well, and place them in a water bath at 40, 45, 50, 55, 60, 65, 70, 75, 80, 85℃ for 1 hour; after the reaction, take out the volumetric flask, add 0.5mL of 10% phosphoric acid to terminate the reaction, add 5mL acetonitrile, fill up to the mark with distilled water, and remove bubbles by ultrasound for 5 minutes; filter into the sample bottle with a syringe filter. Inject into the high performance liquid chromatograph for separation and detection, and the test results are shown in Table 2.

[0117] The water bath temperature is the horizontal axis and the peak area is the vertical axis. The test results are as follows: Figure 1 shown.

[0118] Table 2: Water bath temperature and resolution

[0119] Example Water bath temperature (℃) Peak area Example 1 40 26.4 Example 2 45 83.7 Example 3 50 150.3 Example 4 55 206.8 Example 5 60 340.3 Example 6 65 390.9 Example 7 70 398.7 Example 8 75 391.0 Example 9 80 362.3 Example 10 85 347.6

[0120] Based on Table 2 and Figure 1 The test results show that the peak area of ​​sodium 3-chloro-2-hydroxypropyl sulfonate increases with the increase of temperature. After reaching the peak value, it decreases with the increase of temperature. Among them, when the temperature is 70℃, the peak area is the largest, and the derivatization effect is good at this temperature. Therefore, the derivatization temperature is determined to be 70℃.

[0121] Among them, the liquid chromatogram after separation is as follows Figure 2 As shown. Combined Figure 2 It can be seen from the liquid chromatogram that there is basically no interference peak in the liquid chromatogram; that is, this embodiment uses sodium 4-mercaptobenzoate as a derivatization reagent to effectively eliminate the interference of matrix effects and improve the accuracy of the detection results.

[0122] Accuracy experiment

[0123] Embodiment 11-15:

[0124] Weigh 0.2008 g of sodium 3-chloro-2-hydroxypropyl sulfonate standard into a 100 mL volumetric flask, dilute to the mark with distilled water, the concentration is 2008 mg / L; transfer 10 mL into another 100 mL volumetric flask, dilute to the mark with distilled water, and use as a stock solution (200.8 mg / L) for later use;

[0125] 0.50mL, 1.00mL, 2.00mL, 3.00mL and 4.00mL of the stock solution were respectively measured in 5 50mL volumetric flasks, filled to 20mL with distilled water, 0.5mL of 5% sodium carbonate was added, 0.5mL of 1% sodium 4-mercaptobenzoate was added, and the mixture was placed in a water bath at 70°C for 1 hour; after the reaction was completed, the volumetric flask was taken out, 0.5mL of 10% phosphoric acid was added to terminate the reaction, 5mL of acetonitrile was added, the mixture was filled to the mark with distilled water, and the bubbles were removed by ultrasound for 5 minutes; the mixture was filtered into a sample bottle with a syringe filter, and the mixture was injected into a high performance liquid chromatograph for ultraviolet spectrum detection to obtain the peak area of ​​sodium 3-chloro-2-hydroxypropyl sulfonate. The test results are shown in Table 3:

[0126] Table 3: Peak area for detection of sodium 3-chloro-2-hydroxypropyl sulfonate

[0127] Example Sodium 3-chloro-2-hydroxypropyl sulfonate (mg / L) Peak area Embodiment 11 2.008 68.853 Example 12 4.016 137.891 Embodiment 13 8.032 264.852 Embodiment 14 12.048 397.148 Embodiment 15 16.064 522.155

[0128] Combined with the test results in Table 3, linear regression was performed with the concentration of sodium 3-chloro-2-hydroxypropyl sulfonate as the abscissa and the peak area as the ordinate, and the linear equation was obtained as follows: y=30.524x-2.868, and the correlation coefficient R 2 =0.9979, the linear equation is Figure 3 As shown in Table 3 and Figure 3 The test results show that sodium 3-chloro-2-hydroxypropyl sulfonate has good linearity in the concentration range of 0-16 mg / L.

[0129] Embodiment 16-18:

[0130] Accurately weigh 3 parts of cocamidopropyl hydroxysulfobetaine, the weight is shown in Table 4 (accurate to 1 mg), respectively placed in a 50mL volumetric flask, 15mL of distilled water, 0.5mL of sodium carbonate with a mass concentration of 5% was added, 0.5mL of sodium 4-mercaptobenzoate with a mass concentration of 1% was added dropwise, and the mixture was placed in a water bath at 70°C for 1 hour; after the reaction was completed, the volumetric flask was taken out, 0.5mL of phosphoric acid with a mass concentration of 10% was added to terminate the reaction, 5mL of acetonitrile was added, and distilled water was filled to the scale line, and the bubbles were removed by ultrasound for 5 minutes; filtered into a sample bottle with a syringe filter, and the obtained sample was injected into a high performance liquid chromatograph for ultraviolet spectrum detection to obtain the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate, which was substituted into the linear equations obtained in the above-mentioned Examples 11-15, respectively, and the content of 3-chloro-2-hydroxypropyl sodium sulfonate in each sample was calculated, which was the content of the target substance contained in Examples 16-18, recorded as A value.

[0131] Embodiment 19-21:

[0132] Accurately weigh 3 parts of cocamidopropyl hydroxysulfobetaine, the weight is shown in Table 4 (accurate to 1 mg), and place them in 50 mL volumetric flasks respectively. Take the stock solution (200.8 mg / L) prepared in Examples 11-15 as a reference substance (known concentration), add 0.5 mL (parallel group 1), 1 mL (parallel group 2), and 2 mL (parallel group 3) respectively, add 15 mL of distilled water, add 0.5 mL of 5% mass concentration of sodium carbonate, add 0.5 mL of 1% mass concentration of sodium 4-mercaptobenzoate dropwise, and place in a water bath at 70° C. for 1 hour;

[0133] After the reaction is completed, the volumetric flask is taken out, 0.5 mL of 10% mass concentration phosphoric acid is added to terminate the reaction, 5 mL of acetonitrile is added, and the scale is filled with distilled water, and the bubbles are removed by ultrasound for 5 minutes; the sample is filtered into a sample bottle with a syringe filter, and the obtained sample is injected into a high performance liquid chromatograph for ultraviolet spectrum detection to obtain the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate, which is substituted into the linear equation obtained in the above Examples 11-15 to calculate the content of 3-chloro-2-hydroxypropyl sodium sulfonate in the sample, which is the content of the target substance contained in Examples 19-21, recorded as C value.

[0134] The recovery rate is calculated based on the A value and the C value, where the recovery rate formula is: .

[0135] In the above formula: A is the content of the target substance contained in Examples 16-18; B is the increase in sample concentration after adding the reference substance; C is the content of the target substance contained in Examples 19-21.

[0136] The calculation formula of B value is:

[0137] (Concentration of stock solution*volume of stock solution added) / weight of the corresponding test sample in Examples 19-21.

[0138] Among them, each concentration was prepared in triplicate, and three groups of parallel experiments were performed. The recovery rates were determined under the content determination item, and the test results are shown in Table 4 below; among them, for the recovery rate calculation in Table 4, the A value was calculated by taking the average value of the A value (i.e., 120.86 mg / kg) and substituting it into the above recovery rate calculation formula.

[0139] Table 4: Accuracy test results

[0140]

[0141] According to the test results in Table 4, the average recovery rate of the three parallel group experiments is greater than 99%, indicating that the analyte can be effectively enriched during the treatment of the sample, and the RSD is <3%, indicating that the detection method of this embodiment has excellent accuracy.

[0142] Precision experiment

[0143] Embodiment 22-27:

[0144] The sodium 3-chloro-2-hydroxypropyl sulfonate solution of Example 14 was sampled 6 times continuously, the peak area of ​​the main component was recorded, and the precision was calculated. The test results are shown in Table 5 below:

[0145] Table 5: Precision test results

[0146]

[0147] According to the test results in Table 5, it is shown that the detection method of this embodiment has excellent precision and repeatability.

[0148] Solution stability test

[0149] Embodiment 28-32:

[0150] The sodium 3-chloro-2-hydroxypropyl sulfonate solution of Example 14 was taken and sampled at room temperature for 4, 8, 12, 24 and 48 hours, and the peak area change of the main component was recorded. The test results are shown in Table 6 below:

[0151] Table 6: Solution stability test results

[0152]

[0153] According to the test results in Table 6, it is shown that the detection method of this embodiment has excellent stability of the derivatization solution within 48 hours at room temperature.

[0154] In summary, in this embodiment, sodium 4-mercaptobenzoate is used as a derivatization reagent. Under alkaline conditions, sodium 3-chloro-2-hydroxypropyl sulfonate and sodium 4-mercaptobenzoate undergo a nucleophilic substitution reaction in a water bath to generate sodium 3-(4-carboxymethylphenylthio)-2-hydroxypropyl sulfonate. Among them, sodium 3-(4-carboxymethylphenylthio)-2-hydroxypropyl sulfonate generated by derivatization is very easy to separate in high performance liquid chromatography, and can achieve the purpose of separation and detection through high performance liquid chromatography, so it is easy to eliminate the interference of matrix effect and improve the detection accuracy; at the same time, the detection method of this embodiment is not only easy to operate, but also can effectively improve the separation effect, detection accuracy and precision.

[0155] The technical solutions provided in the embodiments of the present application are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present application. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present application. At the same time, for those skilled in the art, according to the embodiments of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present application.

Claims

1. A method for detecting the content of sodium 3-chloro-2-hydroxypropyl sulfonate, characterized in that: The detection method comprises: Prepare standard solutions of 3-chloro-2-hydroxypropyl sodium sulfonate of different concentrations; react the standard solutions of 3-chloro-2-hydroxypropyl sodium sulfonate of different concentrations with sodium 4-mercaptobenzoate in a water bath under alkaline conditions to obtain standard samples of different concentrations; Performing high performance liquid chromatography ultraviolet detection on standard samples of different concentrations to obtain the peak areas of sodium 3-chloro-2-hydroxypropyl sulfonate in the standard samples of different concentrations; obtaining a linear equation of the corresponding relationship between concentration x and peak area y based on the peak areas corresponding to the standard samples of different concentrations; A cocamidopropyl hydroxysulfobetaine solution is prepared; under alkaline conditions, the cocamidopropyl hydroxysulfobetaine solution is reacted with sodium 4-mercaptobenzoate in a water bath to obtain a sample to be tested; Performing high performance liquid chromatography ultraviolet detection on the sample to be tested to obtain the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate in the sample to be tested; substituting the peak area of ​​3-chloro-2-hydroxypropyl sodium sulfonate in the sample to be tested into a linear equation to calculate the concentration of 3-chloro-2-hydroxypropyl sodium sulfonate in the sample to be tested; Wherein, under alkaline conditions, different concentrations of 3-chloro-2-hydroxypropyl sodium sulfonate standard solutions are reacted with sodium 4-mercaptobenzoate in a water bath to obtain standard samples of different concentrations, including: Add alkali reagent and sodium 4-mercaptobenzoate to standard solutions of sodium 3-chloro-2-hydroxypropyl sulfonate with different concentrations, and place them in a water bath at 70°C for reaction; After the reaction, phosphoric acid and acetonitrile were added, the volume was fixed with distilled water, and bubbles were removed by ultrasonic wave. Standard samples of different concentrations were obtained after filtration. The method comprises preparing a cocamidopropyl hydroxysulfobetaine solution; reacting the cocamidopropyl hydroxysulfobetaine solution with sodium 4-mercaptobenzoate in a water bath under alkaline conditions to obtain a sample to be tested, comprising: Prepare a cocamidopropyl hydroxysulfobetaine solution, add an alkali reagent and sodium 4-mercaptobenzoate to the cocamidopropyl hydroxysulfobetaine solution, and place the solution in a 70°C water bath for reaction; After the reaction, phosphoric acid and acetonitrile were added, the volume was fixed with distilled water, and bubbles were removed by ultrasonic wave, and the sample to be tested was obtained after filtration; The alkaline reagent is sodium carbonate; the chromatographic column used in the high performance liquid chromatography ultraviolet detection is Agilent SB-C8; The chromatographic conditions of the high performance liquid chromatography ultraviolet detection include: Mobile phase A was acetonitrile; Mobile phase B was a mixed solution of acetonitrile, water, and phosphoric acid in a volume ratio of 100:898:2; The gradient elution program of the mobile phase A and the mobile phase B is: Elution was performed with mobile phase A and mobile phase B at a volume ratio of 0:100 for 7 min; Elution was performed with mobile phase A and mobile phase B in a volume ratio of 80:20 for 5 min; The elution was performed with mobile phase A and mobile phase B at a volume ratio of 0:100 for 5 min.

2. The detection method according to claim 1, characterized in that: The linear equation is: y=30.524x-2.868, correlation coefficient R 2 =0.9998.

3. The detection method according to claim 1, characterized in that: The column temperature of the chromatographic column is 30°C.

4. The detection method according to claim 1, characterized in that: The detection wavelength of the high performance liquid chromatography ultraviolet detection is 250-260 nm, and the injection volume is 20 μL.

5. The detection method according to claim 1, characterized in that: In the gradient elution program of mobile phase A and mobile phase B, the flow rate was 1.0 mL / min.

6. The purpose of the detection method according to any one of claims 1 to 5 in the quality control of cocamidopropyl hydroxysultaine products.

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