CN111351829A - Method for measuring sulfur element content in sucralfate - Google Patents
Method for measuring sulfur element content in sucralfate Download PDFInfo
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- CN111351829A CN111351829A CN202010243199.6A CN202010243199A CN111351829A CN 111351829 A CN111351829 A CN 111351829A CN 202010243199 A CN202010243199 A CN 202010243199A CN 111351829 A CN111351829 A CN 111351829A
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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
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- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
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- 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, which adopts a coulometric titration method and has the characteristics of high detection speed, high automation degree, 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 determining the content of sulfur element in sucralfate.
Technical Field
Sucralfate (sucralose), tasteless, has a hygroscopic property. The product is effective in resisting peptic ulcer, and has functions of protecting ulcer surface and promoting ulcer healing. The action mechanism is that under the acidic environment, the compound ions of the compound sulfate and sucrose are dissociated, and the compound ions are polymerized into insoluble colloid with negative charges, and the insoluble colloid can be combined with protein exudates with positive charges on ulcer surfaces to form a protective film to cover the ulcer surfaces and promote ulcer healing. Also has effects of adsorbing pepsin and bile acid; promotes the synthesis of endogenous prostaglandin and adsorbs Epidermal Growth Factor (EGF), so that the prostaglandin is concentrated at the ulcer to be beneficial to the regeneration of mucosa.
Sucralfate has a complex molecular structure 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 sucralfate, and the sulfur content of the sulfur element is regulated by Chinese pharmacopoeia to be 9.0 to 12.5 percent. The traditional chemical titration method has the disadvantages of complicated sample pretreatment steps, complex measurement process and poor durability of the method, thus causing poor precision and accuracy. Therefore, a method for simply and rapidly determining the content of sulfur element in sucralfate with high precision and accuracy is urgently needed to be developed.
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 catalyst and the like.
The purpose of the invention is realized as follows: a method for determining the content of elemental sulfur in sucralfate, said method being coulometric titration, said method comprising the steps of:
(1) conditions of the apparatus
A coulomb sulfur meter;
(2) measurement method
Measuring the moisture of the sample by adopting a drying weight loss method; starting the coulometric sulfur detector for preheating, setting the temperature of the tubular high-temperature furnace, weighing a sample in a sample weighing boat, putting the sample weighing boat in a sample feeding tray, starting a sample feeding program controller, automatically feeding the sample into the furnace, and immediately starting coulometric titration; after the instrument measurement is finished, obtaining a measurement value and calculating a result;
(3) formula for calculation
SDry basis-the concentration of elemental sulphur in the sample%
SComplete baseConcentration of the sulfur element in the whole base sample (aqueous)
m1Measuring the weight of sulfur, mg
m-sample weight, mg
SWater (W)-water content in the sample (loss on drying)%;
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 a microcomputer intelligent biomass fuel oil sulfur detector; the type of the microcomputer intelligent biomass fuel oil product sulfur determinator is TRDL-9E; the weighing amount of the weighed sample is 10-100mg, preferably 30-50 mg; the stirring speed of a coulometric titration electrolytic cell of the coulometric sulfur detector is 400-600r/min, the pH value of the electrolyte is 1-3, the air flow rate is 1300-1700mL/min, and the granularity of the sample is 300-100 meshes; the stirring speed of a coulometric titration electrolytic cell of the coulometric sulfur detector is 500r/min, and the air flow rate is 1500 mL/min.
The key point of the invention is that a coulometric titration method is adopted to determine the content of sulfur element in sucralfate, and the principle of the coulometric titration method is as follows: (1) the sucralfate is combusted and decomposed in air flow, sulfur dioxide generated by sulfur element in sucralfate is absorbed by potassium iodide solution, iodine generated by electrolyzing potassium iodide solution is used for titration, and the content of sulfur element in sucralfate is calculated according to the electric quantity consumed by electrolysis. (2) The speed of the stirring rotor is proper at 400 r/min-600 r/min, and the stirring speed of the stirring rotor is too high, so that the rotor is easy to lose step, jump in an electrolytic cell and damage an electrolytic electrode. Too slow stirring speed can not diffuse the electrolyzed iodine rapidly in time, SO the SO in the electrolytic cell2It was not sufficiently absorbed, and the measurement result was 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, when the electrolyte is strongly acidic, the iodine ion photosensitive reaction is enhanced to generate iodine simple substances, and the iodine simple substances are generated in non-electrolysis manner, so that the electrolysis electric quantity required by complete reaction is reduced, and the measurement result is low, so that the pH value of 1-3 is more suitable for measurement. (4) The air supply amount is kept at 1300-1700ml/min, too low air flow can lead to insufficient combustion of the sample, and too high air flow can lead to the generation of trioxane from sulfur simple substance in the sampleAnd (4) vulcanizing. Both cases result in low measurement results.
Compared with the traditional method, the method for measuring the content of the sulfur element in 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 process for determining the sulfur content in sucralfate.
Detailed Description
The following examples will help to understand the present invention, but these examples are only for illustrative purpose and the present invention is not limited to these contents.
Example one
Coulometric titration method (comparison of results with and without catalyst)
Measuring moisture by a drying weight loss method:
taking about 1g of sucralfate, drying for 3 hours at 105 ℃, and measuring the loss on drying as SWater (W)=12.28%
Starting a coulomb sulfur detector (microcomputer intelligent biomass fuel oil product sulfur determinator, model TRDL-9E, Helianthus domesticus, Tianrun electronics science and technology Co., Ltd., the same below) for preheating, and setting the temperature of a tubular high-temperature furnace to 750 ℃, 850 ℃, 950 ℃ and 1050 ℃. Weighing about 40mg of a sample (the sulfur content is 11.36 percent through a traditional measuring method) in a sample weighing boat, wherein the granularity of the sample is 300-100 meshes, and the sample is respectively covered with 10mg of tungsten trioxide, 5mg of tungsten trioxide and no tungsten trioxide catalyst is added; setting the stirring speed of a coulometric titration electrolytic cell to be 500r/min, keeping the pH value of the electrolyte between 1 and 3 and setting the air flow rate to be 1500 mL/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 coulomb titration immediately, detecting for 5 minutes in a period, obtaining a measured value after the instrument measurement is finished, and calculating a result. The results are compared as follows:
conclusion of the experiment
1. Whether a tungsten trioxide catalyst is added or not at each temperature has no significant influence on the measurement 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 low, and the precision is poor; at 750 ℃, the measurement is significantly lower and the precision is worse, possibly due to insufficient combustion.
In view of the consideration of factors such as energy consumption and reagent consumption, the temperature of 850 ℃ is a more suitable experimental temperature without adding a catalyst.
Example two
Coulometric titration method
Measuring moisture by a drying weight loss method:
taking about 1g of sucralfate, drying for 3 hours at 105 ℃, and measuring the loss on drying as SWater (W)=12.28%。
1. Precision:
starting the coulomb sulfur detector to preheat, and setting the temperature of the tubular high-temperature furnace to 850 ℃. Weighing 40.068mg and 40.504mg of samples in a sample weighing boat, wherein the granularity of the samples is 300 meshes-100 meshes; setting the stirring speed of a coulometric titration electrolytic cell to be 500r/min, keeping the pH value of the electrolyte between 1 and 3 and setting the air flow rate to be 1500 mL/min; the sample weighing boat is put into a sample feeding tray, a sample feeding program controller is started, the sample automatically enters the furnace, coulometric titration is started immediately, and the detection period is 5 minutes. After the instrument measurement is finished, obtaining the measured value S1 all radical=9.66%、S2 all radicalThe result was calculated as 9.71%.
The average value was 11.04% and the deviation was 0.3%
2. Accuracy (recovery):
starting the coulomb sulfur detector to preheat, and setting the temperature of the tubular high-temperature furnace to 850 ℃. Weighing 40.423mg and 40.902mg of samples in a sample weighing boat,the granularity of the sample is 300-100 meshes; 1.053mg of dried elemental sulfur (not counting the weight of the sample) is added into the first sample (40.423 mg of sample); setting the stirring speed of a coulometric titration electrolytic cell to be 500r/min, keeping the pH value of the electrolyte between 1 and 3 and setting the air flow rate to be 1500 mL/min; the sample weighing boat is put into a sample feeding tray, a sample feeding program controller is started, the sample automatically enters the furnace, coulometric titration is started immediately, and the detection period is 5 minutes. After the instrument measurement is finished, obtaining the measured value SWhole base (Standard + sample)=12.39%、S2 full base (sample)The result was calculated as 9.74%.
Computing
EXAMPLE III
Traditional measuring method (contrast test)
Measuring moisture by a drying weight loss method:
taking about 1g of sucralfate, drying at 105 deg.C for 3 hr, and measuring the loss on drying to be 12.28%
Determination of sulfur content by chemical titration:
1. precision:
0.9999g and 0.9998g of sucralfate are weighed respectively, put into a beaker, added with 10ml of nitric acid (1 → 2) solution and 10ml of water respectively, and slowly boiled for 10 minutes. Adding ammonia solution until it is alkaline, adding 5ml ammonia solution, boiling for 1 min, and cooling. Respectively transferring to a 100ml measuring flask, diluting to a scale with water, shaking up, respectively filtering with dry filter paper, discarding about 20ml of primary filtrate, precisely measuring 10ml of secondary filtrate, placing in a 250ml conical flask, adding 1mol/L hydrochloric acid solution for neutralization to make the solution acidic, adding 3 more drops, precisely adding 10ml of barium chloride-magnesium chloride solution, shaking up, placing for a moment, adding 15ml of ammonia-ammonium chloride buffer solution (pH10.0), 5ml of triethanolamine solution (1 → 2) and a small amount of chrome black T indicator, titrating with ethylene diamine tetraacetic acid disodium titrate solution (0.05095mol/L), and correcting the titration result with a blank test.
The blank consumption was measured as volume VBlank 119.50ml and VBlank 219.55ml, average 19.45 ml.
The volume of the ethylene diamine tetraacetic acid titration solution consumed by the sample is VSample 113.24ml and VSample 2=13.47ml。
Calculating the sulphur content
The average was 11.36% with a deviation of 1.9%.
2. Accuracy (recovery):
1.0012g and 1.0023g of sucralfate are weighed respectively, 0.0172g of dried elemental sulfur (not counting the weight of the sample) is added into the first part, the first part is placed into a beaker, 10ml of nitric acid (1 → 2) solution and 10ml of water are added respectively, and the mixture is slowly boiled for 10 minutes. Adding ammonia solution until it is alkaline, adding 5ml ammonia solution, boiling for 1 min, and cooling. Respectively transferring to a 100ml measuring flask, diluting to a scale with water, shaking up, respectively filtering with dry filter paper, discarding about 20ml of primary filtrate, precisely measuring 10ml of secondary filtrate, placing in a 250ml conical flask, adding 1mol/L hydrochloric acid solution for neutralization to make the solution acidic, adding 3 more drops, precisely adding 10ml of barium chloride-magnesium chloride solution, shaking up, placing for a moment, adding 15ml of ammonia-ammonium chloride buffer solution (pH10.0), 5ml of triethanolamine solution (1 → 2) and a small amount of chrome black T indicator, titrating with ethylene diamine tetraacetic acid disodium titrate solution (0.05095mol/L), and correcting the titration result with a blank test.
The blank consumption was measured as volume VBlank 119.50ml and VBlank 219.60ml, average 19.55ml
The volume of the ethylene diamine tetraacetic acid titration solution consumed by the sample is VStandard + sample 112.54ml and VSample 2=13.77ml
Calculating the sulphur content
Claims (8)
1. A method for measuring the content of sulfur element in sucralfate is characterized in that: the method is a coulometric titration method, and comprises the following steps:
(1) conditions of the apparatus
A coulomb sulfur meter;
(2) measurement method
Measuring the moisture of the sample by adopting a drying weight loss method; starting the coulometric sulfur detector for preheating, setting the temperature of the tubular high-temperature furnace, weighing a sample in a sample weighing boat, putting the sample weighing boat in a sample feeding tray, starting a sample feeding program controller, automatically feeding the sample into the furnace, and immediately starting coulometric titration; after the instrument measurement is finished, obtaining a measurement value and calculating a result;
(3) formula for calculation
SDry basis-the concentration of elemental sulphur in the sample%
SComplete baseConcentration of the sulfur element in the whole base sample (aqueous)
m1Measuring the weight of sulfur, mg
m-sample weight, mg
SWater (W)Water content in the sample (loss on drying)%.
2. The method for determining the sulfur content in sucralfate according to claim 1, wherein: the temperature of the tubular high-temperature furnace is 800-1000 ℃.
3. The method for determining the sulfur content in sucralfate according to claim 2, wherein: the temperature of the tubular high-temperature furnace is 850-950 ℃.
4. The method for determining the sulfur content in sucralfate according to claim 1, wherein: the coulomb sulfur detector is selected from a microcomputer intelligent biomass fuel oil sulfur detector.
5. The method for determining the sulfur content in sucralfate according to claim 4, wherein: the type of the microcomputer intelligent biomass fuel oil product sulfur determinator is TRDL-9E.
6. The method for determining the sulfur content in sucralfate according to claim 1, wherein: the weighed amount of the weighed sample is 10-100mg, and preferably the weighed amount of the weighed sample is 30-50 mg.
7. The method for determining the sulfur content in sucralfate according to 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 the electrolyte is 1-3, the air flow rate is 1300-1700mL/min, and the granularity of the sample is 300-100 meshes.
8. The method for determining the sulfur content in sucralfate according to claim 7, wherein: the stirring speed of a coulometric titration electrolytic cell of the coulometric sulfur detector is 500r/min, and the air flow rate is 1500 mL/min.
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Cited By (2)
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---|---|---|---|---|
CN112763722A (en) * | 2020-12-24 | 2021-05-07 | 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 |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4172705A (en) * | 1978-04-12 | 1979-10-30 | Envirotech Corporation | Process and apparatus for sulfur analysis |
US4409336A (en) * | 1981-02-17 | 1983-10-11 | Standard Oil Company (Indiana) | Method of analysis for determining very low sulfur levels in volatilizable samples |
CN101571507A (en) * | 2008-04-29 | 2009-11-04 | 浙江省电力试验研究院 | Microcoulomb analysis method for chlorinity high-temperature burning of organic phosphate fire-resistant oil and device thereof |
CN103728360A (en) * | 2014-01-02 | 2014-04-16 | 广东电网公司电力科学研究院 | Method for determining content of total sulfur in biomass fuel |
CN108982750A (en) * | 2018-07-09 | 2018-12-11 | 湖州吉昌化学有限公司 | The detection method of chlorinity in a kind of 2- ethyl hydrazine |
-
2020
- 2020-03-31 CN CN202010243199.6A patent/CN111351829B/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4172705A (en) * | 1978-04-12 | 1979-10-30 | Envirotech Corporation | Process and apparatus for sulfur analysis |
US4409336A (en) * | 1981-02-17 | 1983-10-11 | Standard Oil Company (Indiana) | Method of analysis for determining very low sulfur levels in volatilizable samples |
CN101571507A (en) * | 2008-04-29 | 2009-11-04 | 浙江省电力试验研究院 | Microcoulomb analysis method for chlorinity high-temperature burning of organic phosphate fire-resistant oil and device thereof |
CN103728360A (en) * | 2014-01-02 | 2014-04-16 | 广东电网公司电力科学研究院 | Method for determining content of total sulfur in biomass fuel |
CN108982750A (en) * | 2018-07-09 | 2018-12-11 | 湖州吉昌化学有限公司 | The detection method of chlorinity in a kind of 2- ethyl hydrazine |
Non-Patent Citations (2)
Title |
---|
梁明卉: "催化剂用量对库仑法测硫的影响", 《山西科技》 * |
王红卫 等: "管式炉燃烧– 碘量库仑滴定法测定石油焦中总硫含量", 《化学分析计量》 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112763722A (en) * | 2020-12-24 | 2021-05-07 | 东北制药集团股份有限公司 | Method for detecting sucralfatin affinity |
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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