Karl Fischer & Potentiometric Titration Application Library
Water in Gasoline and Petroleum Products – Karl Fischer Method (ASTM D6304)
Accurate water determination in gasoline and heavy oil using Karl Fischer titration. Detect trace moisture, prevent corrosion, and improve fuel quality control.
Moisture Determination in Pharmaceuticals by Karl Fischer Back-Titration (Japanese Pharmacopoeia Method)
Karl Fischer moisture determination in pharmaceuticals using back-titration methods. Ensure compliance with Japanese Pharmacopoeia and accurate QC results.
race Moisture Determination in Pharmaceuticals by Coulometric Karl Fischer (Japanese Pharmacopoeia Method)
Trace moisture determination in pharmaceuticals using coulometric Karl Fischer titration. Ensure compliance with Japanese Pharmacopoeia methods.
Moisture Determination in Pharmaceuticals by Karl Fischer Titration
Karl Fischer moisture determination in pharmaceuticals following Japanese Pharmacopoeia methods. Ensure accurate, compliant quality control results.
Sugars – KF Volumetry, granulated sugar Factor standardization with water standard | Karl Fischer titrator AQV-300/MOIVO-A19
Water contents of granulated sugar could be determined by Karl Fischer volumetric titrator. In volumetric titration, titrant have a factor which means the amount to react with water per 1 mL of titrant. The factor is pre-determined before sample measurement and water content of sample is calculated from the consumed titrant volume by sample measurement.
This application introduces an example for the water determination in granulated sugar. Due to the low water content of this sample, a relatively large amount of sample must be added, but the solubility in methanol as titration solvent is not sufficient. Sugars have tendency to dissolve in formamide. Therefore a mixed solvent of formamide and methanol was chosen as the titration solvent. To make it easier to dissolve the sample, the titration cell was heated to 45 °C using an outer chamber for flowing warm water.
Since the water content of the granulated sugar is often a few hundred ppm, the titrant with low factor value, as 1 mg/mL was used. When pure water is used as the standard material of factor standardization for low factor titrant, the amount of pure water added should be as small as 10 to 20 mg, which makes accurate addition and weighing difficult. Therefore, water standard material which is the solution containing 1 % of water sealed in glass ampoule is used for the factor standardization.
This application introduces an example for the water determination in granulated sugar. Due to the low water content of this sample, a relatively large amount of sample must be added, but the solubility in methanol as titration solvent is not sufficient. Sugars have tendency to dissolve in formamide. Therefore a mixed solvent of formamide and methanol was chosen as the titration solvent. To make it easier to dissolve the sample, the titration cell was heated to 45 °C using an outer chamber for flowing warm water.
Since the water content of the granulated sugar is often a few hundred ppm, the titrant with low factor value, as 1 mg/mL was used. When pure water is used as the standard material of factor standardization for low factor titrant, the amount of pure water added should be as small as 10 to 20 mg, which makes accurate addition and weighing difficult. Therefore, water standard material which is the solution containing 1 % of water sealed in glass ampoule is used for the factor standardization.
Validation test with water standard KF Coulometry – Heat evaporation method | Karl Fischer titrator AQ-300/MOICO-A19/EV-2000
A heat evaporation method using Karl Fischer titrator combined with solid evaporator is suitable for insoluble sample in anode solution, such as plastics and inorganic compounds. The measurement of with the heat evaporation method is carried out by heating the sample while a carrier gas is blown into the evaporation chamber and introducing the evaporated moisture together with the carrier gas into the electrolysis cell.
This application introduces an example of measurement of solid water standard for validation of titrator system with solid evaporator.
This application introduces an example of measurement of solid water standard for validation of titrator system with solid evaporator.
Moisture Determination in Sugars (Glucose, Fructose, Sucrose) Using Karl Fischer Titration
Accurate moisture determination in sugars using Karl Fischer titration. Analyze glucose, fructose, and sucrose powders with reliable, reproducible results.
Ketones, Cyclohexanone – KF Coulometry, Cooled direct injection, Azeotropic distillation | Karl Fischer titrator AQ-300/MOICO-A19/EV-2000L
Water content of cyclohexanone is determined by Karl Fischer coulometric titrator. In coulometric titration, iodine of Karl Fischer reagent is generated by electrolysis and generated iodine quantitatively reacts with water. Reaction formula is described below.
H₂O ＋ I₂ ＋ SO₂ ＋ 3RN ＋ CH₃OH → 2RN・HI ＋ RN・HSO₄CH₃
2RN・HI → I₂ ＋ 2RN ＋ 2H⁺ ＋ 2e⁻
Ketones and aldehydes would interfere the Karl Fischer reaction by side-reaction with methanol (formula (1)).
R₂CO + 2CH₃OH → R₂C(OCH₃)₂ + H₂O ・・・(1)
Therefore it is necessary to use methanol-free anode and cathode solution. There are commercially available reagents with a special composition for ketones and aldehydes. However, cyclohexanone has particularly a strong side reaction activity, so it is difficult to measure by direct injection method at room temperature. In the measurement of cyclohexanone, it is effective to lower the activity of side reaction by cooling or to separate cyclohexanone and water by distillation.
This application introduces an example for the water determination in cyclohexanone with cooled direct injection method and azeotropic distillation method
H₂O ＋ I₂ ＋ SO₂ ＋ 3RN ＋ CH₃OH → 2RN・HI ＋ RN・HSO₄CH₃
2RN・HI → I₂ ＋ 2RN ＋ 2H⁺ ＋ 2e⁻
Ketones and aldehydes would interfere the Karl Fischer reaction by side-reaction with methanol (formula (1)).
R₂CO + 2CH₃OH → R₂C(OCH₃)₂ + H₂O ・・・(1)
Therefore it is necessary to use methanol-free anode and cathode solution. There are commercially available reagents with a special composition for ketones and aldehydes. However, cyclohexanone has particularly a strong side reaction activity, so it is difficult to measure by direct injection method at room temperature. In the measurement of cyclohexanone, it is effective to lower the activity of side reaction by cooling or to separate cyclohexanone and water by distillation.
This application introduces an example for the water determination in cyclohexanone with cooled direct injection method and azeotropic distillation method
Ketones – KF Coulometry, Direct-Injection Methyl ethyl ketone and Acetone | Karl Fischer titrator AQ-300/MOICO-A19
Water content of ketones could be determined by Karl Fischer coulometric titrator. In coulometric titration, iodine of Karl Fischer reagent is generated by electrolysis and generated iodine quantitatively reacts with water. Reaction formula is described below.
H₂O ＋ I₂ ＋ SO₂ ＋ 3RN ＋ CH₃OH → 2RN・HI ＋ RN・HSO₄CH₃
2RN・HI → I₂ ＋ 2RN ＋ 2H⁺ ＋ 2e⁻
When the sample is liquid, generally sample is measured by direct injection into the titration cell. Anode solution containing methanol as solvent is generally used for various sample. However, in the measurement of ketones and aldehydes, since these react with methanol to produce water, the measurement result tends to be higher than the true value (formula (1)).
R₂CO + 2CH₃OH → R₂C(OCH₃)₂ + H₂O ・・・(1)
For above reason, Karl Fischer reagent without methanol should be used for water determination of ketones and aldehydes. There are commercially available reagents with a special composition for ketones and aldehydes. This chapter introduces an example for the water determination in methyl ethyl ketone and acetone. These samples are often used as paint solvents, raw materials of adhesives, and synthetic resins.
H₂O ＋ I₂ ＋ SO₂ ＋ 3RN ＋ CH₃OH → 2RN・HI ＋ RN・HSO₄CH₃
2RN・HI → I₂ ＋ 2RN ＋ 2H⁺ ＋ 2e⁻
When the sample is liquid, generally sample is measured by direct injection into the titration cell. Anode solution containing methanol as solvent is generally used for various sample. However, in the measurement of ketones and aldehydes, since these react with methanol to produce water, the measurement result tends to be higher than the true value (formula (1)).
R₂CO + 2CH₃OH → R₂C(OCH₃)₂ + H₂O ・・・(1)
For above reason, Karl Fischer reagent without methanol should be used for water determination of ketones and aldehydes. There are commercially available reagents with a special composition for ketones and aldehydes. This chapter introduces an example for the water determination in methyl ethyl ketone and acetone. These samples are often used as paint solvents, raw materials of adhesives, and synthetic resins.
Moisture Determination in Ketones and Aldehydes by Karl Fischer Titration (Avoiding False High Results)
Avoid false moisture results in ketones and aldehydes during Karl Fischer titration. Understand side reactions and improve analytical accuracy.
Moisture Determination in Pharmaceutical Powders by Karl Fischer Titration
👉 Moisture determination in pharmaceutical powders using Karl Fischer titration. Accurate analysis of excipients and amino acid compounds.
Moisture Determination in Pharmaceutical Excipients by Karl Fischer Titration
Moisture determination in pharmaceutical excipients and surfactants using Karl Fischer titration. Accurate analysis for reliable quality control.
