CN111351829B - Method for measuring content of sulfur element in sucralfate - Google Patents
Method for measuring content of sulfur element in sucralfate Download PDFInfo
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- CN111351829B CN111351829B CN202010243199.6A CN202010243199A CN111351829B CN 111351829 B CN111351829 B CN 111351829B CN 202010243199 A CN202010243199 A CN 202010243199A CN 111351829 B CN111351829 B CN 111351829B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/416—Systems
- G01N27/42—Measuring deposition or liberation of materials from an electrolyte; Coulometry, i.e. measuring coulomb-equivalent of material in an electrolyte
- G01N27/423—Coulometry
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/416—Systems
- G01N27/42—Measuring deposition or liberation of materials from an electrolyte; Coulometry, i.e. measuring coulomb-equivalent of material in an electrolyte
- G01N27/426—Measuring deposition or liberation of materials from an electrolyte; Coulometry, i.e. measuring coulomb-equivalent of material in an electrolyte by weighing
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- G—PHYSICS
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- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/416—Systems
- G01N27/42—Measuring deposition or liberation of materials from an electrolyte; Coulometry, i.e. measuring coulomb-equivalent of material in an electrolyte
- G01N27/44—Measuring deposition or liberation of materials from an electrolyte; Coulometry, i.e. measuring coulomb-equivalent of material in an electrolyte using electrolysis to generate a reagent, e.g. for titration
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Abstract
The invention relates to a method for measuring the content of sulfur element in sucralfate in the field of pharmaceutical analysis, which adopts a coulometric titration method and has the characteristics of high detection speed, high degree of automation, high accuracy, good repeatability, no need of adding a catalyst and the like.
Description
Technical Field
The invention belongs to the field of pharmaceutical analysis, and particularly relates to a method for measuring the content of sulfur element in sucralfate.
Technical Field
Sucralfate (Sucralfate), is odorless and has hygroscopicity. The product is effective in resisting peptic ulcer, and has effects of protecting ulcer surface and promoting ulcer healing. The mechanism of action is that under the acid environment, the product dissociates the compound ion of the sucrose sulfate, the compound ion is polymerized into insoluble colloid with negative charge, and can be combined with protein exudation with positive charge on the ulcer surface to form a protective film which covers the ulcer surface to promote the ulcer healing. Also has the effect of adsorbing pepsin and bile acid; promote synthesis of endogenous prostaglandin and adsorb Epidermal Growth Factor (EGF), so that it is concentrated at ulcer to promote mucosa regeneration.
The molecular structure of sucralfate is complex and does not have a fixed molecular formula. The content index of the sulfur element is an important quality index for controlling the content of the sucralfate, and the Chinese pharmacopoeia prescribes that the sulfur content is 9.0-12.5 percent. The traditional chemical titration method has complicated sample pretreatment steps, complex measurement process and poor durability, and results in poor precision and accuracy. Therefore, a method for simply, conveniently and rapidly determining the content of sulfur element in sucralfate has to be developed with high precision and accuracy.
Disclosure of Invention
The invention aims to provide a method for measuring the content of sulfur element in sucralfate, which has the characteristics of high detection speed, high automation degree, high accuracy, good repeatability, no need of adding a catalyst and the like.
The purpose of the invention is realized in the following way: a method for determining elemental sulfur content in sucralfate, said method being a coulometric titration method comprising the steps of:
(1) Instrument conditions
Coulometric sulfur meter;
(2) Measurement method
Measuring the moisture of a sample by adopting a drying weightlessness method; starting up the coulomb sulfur measuring instrument for preheating, setting the temperature of a tubular high-temperature furnace, weighing a sample in a sample weighing boat, placing the sample weighing boat in a sample conveying tray, starting a sample conveying program controller, automatically feeding the sample into the furnace, and starting coulomb titration immediately; after the instrument measurement is finished, obtaining a measurement value and calculating a result;
(3) Calculation formula
S Dry basis Concentration of elemental sulfur in the sample,%
S All-basic Concentration of elemental sulfur in the whole base sample,%
m 1 Weight of sulfur measured, mg
m-weight of sample, mg
S Water and its preparation method -moisture content in sample (loss on drying method),%;
the temperature of the tubular high-temperature furnace is 800-1000 ℃; the temperature of the tubular high-temperature furnace is 850-950 ℃; the coulomb sulfur detector is selected from microcomputer intelligent biomass fuel oil product sulfur detector; the model of the microcomputer intelligent biomass fuel oil product sulfur determination instrument is TRDL-9E; the weighing amount of the weighed sample is 10-100mg, and the weighing amount of the weighed sample is 30-50mg; the stirring speed of a coulometric titration electrolytic cell of the coulometric sulfur meter is 400-600r/min, the pH value of electrolyte is 1-3, the air flow rate is 1300-1700mL/min, and the granularity of a sample is 300-100 meshes; the stirring speed of a coulometric titration electrolytic cell of the coulometric sulfur meter is 500r/min, and the air flow rate is 1500mL/min.
The invention is characterized in that a method for measuring the content of sulfur element in sucralfate by using a coulometric titration method is adopted, and the principle of the coulometric titration method is as follows: (1) The sulfur dioxide generated by sulfur elements in the sulfur aluminum saccharate is absorbed by potassium iodide solution, iodine generated by electrolyzing the potassium iodide solution is used for titration, and the content of the sulfur elements in the sulfur aluminum saccharate is calculated according to the electric quantity consumed by electrolysis. (2) The speed of the stirring rotor is more suitable at 400-600r/min, the rotating speed of the stirring rotor is too high, the rotor is easy to lose synchronization, and the stirring rotor is jumped in a disorder way in the electrolytic cell to damage the electrolytic electrode. Too slow stirring speed can not timely and rapidly diffuse the electrolyzed iodine, SO in the electrolytic cell 2 And cannot be absorbed sufficiently, and the measurement result is low. (3) The pH value of the electrolyte is more than 1, the acidity of the electrolyte is continuously increased along with repeated use of the electrolyte, the photosensitive reaction of iodide ions is enhanced after the electrolyte is strongly acidic, and iodine simple substances are generated, and the electrolysis electric quantity required by complete reaction is reduced due to the fact that the iodine simple substances are generated in a non-electrolysis mode, and the measurement result is low, so that the pH value is 1-3, and the method is more suitable for measurement. (4) The air supply should be maintained at 1300-1700ml/min, too little ventilation will result in insufficient combustion of the sample, and too high ventilation will result in the formation of sulfur trioxide from elemental sulfur in the sample. Both cases result in a lower measurement result.
Compared with the traditional method, the method for measuring the content of the sulfur element in the sucralfate has the characteristics of high detection speed (5 minutes in the method, 1 hour in the traditional method), high automation degree, high accuracy, good repeatability, no need of adding a catalyst and the like.
Drawings
FIG. 1 shows a measurement flow for determining the content of elemental sulfur in sucralfate.
Detailed Description
The following examples will aid in the understanding of the invention, but are merely illustrative of the invention and the invention is not limited thereto.
Example 1
Coulomb titration (comparison of results with and without catalyst)
Dry weight loss method for measuring moisture:
taking about 1g of sucralfate, drying at 105 ℃ for 3 hours, and measuring the weight loss on drying to be S Water and its preparation method ＝12.28％
The coulomb sulfur detector (microcomputer intelligent biomass fuel oil product sulfur detector, model TRDL-9E, oil filling arm wall city Tianrun electronic technology Co., ltd., hereinafter the same) is started and preheated, and the temperature of the tube type high-temperature furnace is set to 750 ℃, 850 ℃, 950 ℃ and 1050 ℃ respectively. Weighing about 40mg of a sample (sulfur content is 11.36 percent measured by a traditional measurement method) in a weighing boat, wherein the granularity of the sample is 300-100 meshes, and 10mg of tungsten trioxide and 5mg of tungsten trioxide are respectively covered and a tungsten trioxide catalyst is not added; setting the stirring speed of a coulometric titration electrolytic cell to be 500r/min, keeping the pH value of the electrolyte to be 1-3, and setting the air flow rate to be 1500mL/min; and (3) placing the sample weighing boat into a sample feeding tray, starting a sample feeding program controller, automatically feeding the sample into the furnace, starting coulometric titration immediately, detecting for 5 minutes, and obtaining a measurement value and a calculation result after the instrument measurement is finished. The results were compared as follows:
conclusion of the experiment
1. Whether tungsten trioxide catalyst is added at each temperature has no obvious influence on measured value and precision.
2. The measured values have no obvious difference at 850 ℃ and 950 ℃, and the precision is high; at 1050 ℃, the measured value is lower, and the precision is poor; at 750 ℃, the measured value is significantly lower, the precision is poor, and the insufficient combustion may be caused.
In consideration of factors such as energy consumption, reagent consumption and the like, no catalyst is added, and the temperature of 850 ℃ is a proper experimental temperature.
Example two
Coulomb titration method
Dry weight loss method for measuring moisture:
taking about 1g of sucralfate, drying at 105 ℃ for 3 hours, and measuring the weight loss on drying to be S Water and its preparation method ＝12.28％。
1. Precision:
the coulomb sulfur detector is started up for preheating, and the temperature of the tubular high-temperature furnace is set to 850 ℃. Weighing about 40.068mg and 40.504mg of the sample in a weighing boat, wherein the granularity of the sample is 300-100 meshes; setting the stirring speed of a coulometric titration electrolytic cell to be 500r/min, keeping the pH value of the electrolyte to be 1-3, and setting the air flow rate to be 1500mL/min; and (3) placing the sample weighing boat into a sample feeding tray, starting a sample feeding program controller, automatically feeding the sample into the furnace, and starting coulometric titration immediately, wherein the detection period is 5 minutes. After the instrument measurement is finished, obtaining a measurement value S 1 all radical ＝9.66％、S 2 all radicals =9.71%, calculated result.
Calculation of
Average 11.04% and deviation 0.3%
2. Accuracy (recovery):
the coulomb sulfur detector is started up for preheating, and the temperature of the tubular high-temperature furnace is set to 850 ℃. Weighing about 40.423mg and 40.902mg of the sample in a weighing boat, wherein the granularity of the sample is 300-100 meshes; 1.053mg of dried elemental sulfur (excluding the weight of the sample) was added to the first sample (i.e., 40.423mg sample); setting the stirring speed of a coulometric titration electrolytic cell to be 500r/min, keeping the pH value of the electrolyte to be 1-3, and setting the air flow rate to be 1500mL/min; and (3) placing the sample weighing boat into a sample feeding tray, starting a sample feeding program controller, automatically feeding the sample into the furnace, and starting coulometric titration immediately, wherein the detection period is 5 minutes. After the instrument measurement is finished, obtaining a measurement value S All basis (standard + sample) ＝12.39％、S 2 all base (sample) =9.74%, calculated result.
Calculation of
Example III
Traditional measurement (comparative test)
Dry weight loss method for measuring moisture:
about 1g of sucralfate was taken and dried at 105℃for 3 hours, and the loss on drying was found to be 12.28%
Sulfur content was measured by chemical titration:
1. precision:
separately, 0.9999g of sucralfate and 0.9998g of sucralfate were weighed, placed in a beaker, 10ml of nitric acid (1- > 2) solution and 10ml of water were added, and boiled slowly for 10 minutes. Adding ammonia solution to alkaline, adding 5ml ammonia solution, boiling for 1 min, and cooling. Respectively transferring into 100ml measuring flask, diluting with water to scale, shaking, filtering with dry filter paper, discarding about 20ml of primary filtrate, precisely measuring 10ml of secondary filtrate, placing into 250ml conical flask, neutralizing with 1mol/L hydrochloric acid solution to make the solution acidic, adding 3 drops more, precisely adding 10ml of barium chloride-magnesium chloride solution, shaking, standing for a while, adding 15ml of ammonia-ammonium chloride buffer (pH 10.0), 5ml of triethanolamine solution (1- > 2) and small amount of chrome black T indicator, titrating with disodium ethylenediamine tetraacetate titration solution (0.05095 mol/L), and correcting titration result with blank test.
The volumes of the blank consumption were measured as V Blank 1 = 19.50ml and V Blank 2 =19.55 ml, average value 19.45ml.
The volume of the sample consumption disodium ethylenediamine tetraacetate titration solution is V Sample 1 =13.24 ml and V Sample 2 ＝13.47ml。
Calculation of sulphur content
The average value was 11.36% and the deviation was 1.9%.
2. Accuracy (recovery):
1.0012g and 1.0023g of sucralfate are weighed respectively, 0.0172g of dried elemental sulfur (excluding the weight of the sample) is added into the first portion, the mixture is placed into a beaker, 10ml of nitric acid (1- & gt 2) solution and 10ml of water are added into the mixture respectively, and the mixture is boiled slowly for 10 minutes. Adding ammonia solution to alkaline, adding 5ml ammonia solution, boiling for 1 min, and cooling. Respectively transferring into 100ml measuring flask, diluting with water to scale, shaking, filtering with dry filter paper, discarding about 20ml of primary filtrate, precisely measuring 10ml of secondary filtrate, placing into 250ml conical flask, neutralizing with 1mol/L hydrochloric acid solution to make the solution acidic, adding 3 drops more, precisely adding 10ml of barium chloride-magnesium chloride solution, shaking, standing for a while, adding 15ml of ammonia-ammonium chloride buffer (pH 10.0), 5ml of triethanolamine solution (1- > 2) and small amount of chrome black T indicator, titrating with disodium ethylenediamine tetraacetate titration solution (0.05095 mol/L), and correcting titration result with blank test.
The volumes of the blank consumption were measured as V Blank 1 = 19.50ml and V Blank 2 =19.60 ml, average 19.55ml
The volume of the sample consumption disodium ethylenediamine tetraacetate titration solution is V Mark + sample 1 =12.54 ml and V Sample 2 ＝13.77ml
Calculation of sulphur content
Claims (9)
1. A method for measuring the content of sulfur element in sucralfate is characterized in that: the method is a coulometric titration method comprising the steps of:
(1) Instrument conditions
Coulometric sulfur meter;
(2) Measurement method
Measuring the moisture of a sample by adopting a drying weightlessness method; starting up the coulomb sulfur measuring instrument for preheating, setting the temperature of a tubular high-temperature furnace, weighing a sample in a sample weighing boat, placing the sample weighing boat in a sample conveying tray, starting a sample conveying program controller, automatically feeding the sample into the furnace, and starting coulomb titration immediately; after the instrument measurement is finished, obtaining a measurement value and calculating a result;
(3) Calculation formula
S Dry basis Concentration of elemental sulfur in the sample,%
S All-basic -concentration of elemental sulphur in aqueous whole base sample,%
m 1 Weight of sulfur measured, mg
m-weight of sample, mg
S Water and its preparation method -moisture content,%, of the sample measured by loss on drying method.
2. The method for determining the content of elemental sulfur in sucralfate as claimed in claim 1, wherein: the temperature of the tubular high-temperature furnace is 800-1000 ℃.
3. The method for determining the content of elemental sulfur in sucralfate as claimed in claim 2, wherein: the temperature of the tubular high-temperature furnace is 850-950 ℃.
4. The method for determining the content of elemental sulfur in sucralfate as claimed in claim 1, wherein: the coulomb sulfur detector is selected from microcomputer intelligent biomass fuel oil product sulfur detector.
5. The method for determining the content of elemental sulfur in sucralfate as claimed in claim 4, wherein: the model of the microcomputer intelligent biomass fuel oil product sulfur determination instrument is TRDL-9E.
6. The method for determining the content of elemental sulfur in sucralfate as claimed in claim 1, wherein: the weighing amount of the weighed sample is 10-100mg.
7. The method for determining the content of elemental sulfur in sucralfate as claimed in claim 6, wherein: the weighing amount of the weighed sample is 30-50mg.
8. The method for determining the content of elemental sulfur in sucralfate as claimed in claim 1, wherein: the stirring speed of a coulometric titration electrolytic cell of the coulometric sulfur detector is 400-600r/min, the pH value of electrolyte is 1-3, the air flow rate is 1300-1700mL/min, and the granularity of a sample is 300-100 meshes.
9. The method for determining the content of elemental sulfur in sucralfate as claimed in claim 8, wherein: the stirring speed of a coulometric titration electrolytic cell of the coulometric sulfur meter is 500r/min, and the air flow rate is 1500mL/min.
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| CN112763722B (en) * | 2020-12-24 | 2022-12-06 | 东北制药集团股份有限公司 | Method for detecting sucralfatin affinity |
| CN114088794A (en) * | 2021-09-14 | 2022-02-25 | 江苏地质矿产设计研究院(中国煤炭地质总局检测中心) | Method for measuring sulfur content in soil and water system sediment by coulometry titration |
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