Karl Fischer & Potentiometric Titration Application Library
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.
Moisture Determination in Pharmaceuticals by Karl Fischer Back-Titration
Moisture determination in pharmaceuticals using Karl Fischer back-titration. Ideal for complex or reactive samples requiring accurate results.
Moisture Determination in Pharmaceutical Solvents by Karl Fischer Titration (Direct Injection)
Moisture determination in pharmaceutical solvents such as propylene glycol and glycerin using Karl Fischer titration. Ideal for direct injection analysis.
Trace Moisture Determination in Pharmaceuticals by Coulometric Karl Fischer Titration
Trace moisture determination in pharmaceutical compounds using coulometric Karl Fischer titration. Ideal for low-level water analysis.
Nitriles | Karl Fischer titrator AQ-300/MOICO-A19
H₂O ＋ I₂ ＋ SO₂ ＋ 3RN ＋ CH₃OH → 2RN・HI ＋ RN・HSO₄CH₃
2RN・HI → I₂ ＋ 2RN ＋ 2H⁺ ＋ 2e⁻
Nitriles do not interfere the Karl Fischer reaction and direct injection method could apply. Anode solution is selected in accordance with sample solubility. General use of anode solution contain methanol as solvent. When the sample like a long chain hydrocarbon has poor solubility in methanol, anode solution containing chloroform or hexanol or toluene is used.
Amines | Karl Fischer titrator AQ-300/MOICO-A19
H₂O ＋ I₂ ＋ SO₂ ＋ 3RN ＋ CH₃OH → 2RN・HI ＋ RN・HSO₄CH₃
2RN・HI → I₂ ＋ 2RN ＋ 2H⁺ ＋ 2e⁻
The amines change anode solution pH to basic. In the case of an amine with stronger basicity than benzylamine (pKa = 9.34¹)) as a guideline, there are such effects as the end point becomes unclear. Therefore, when measuring a strongly basic amine, add a neutralizing agent to the anode solution beforehand to suppress the influence of undesirable effect caused by adding the sample. This application introduces an example for the water determination in cyclohexylamine(liquid), diethanolamine(liquid) and imidazole(solid). Reference
1) H. K. Hall, J. Am. Chem. Soc. (1957) 79 5441.
Moisture Determination in Ethers and Esters | Karl Fischer Titration Method (AQ-300 / MOICO-A19)
H₂O ＋ I₂ ＋ SO₂ ＋ 3RN ＋ CH₃OH → 2RN・HI ＋ RN・HSO₄CH₃
2RN・HI → I₂ ＋ 2RN ＋ 2H⁺ ＋ 2e⁻
Ethers and esters do not interfere the Karl Fischer reaction and direct injection method could apply. Anode solution is selected from General-use or Oil in accordance with sample solubility. General-use anode solution contains methanol as solvent. When the sample has low solubility in methanol, the use of anode solution for oil is appropriate. One exception is a sample containing vinyl group, which reacts with KF reagent and interferes the titration. When fritless cell is used, cathode solution is not necessary.
Water Content in Oil Products by Karl Fischer Titration | ASTM D6304
Learn how Karl Fischer coulometric titration accurately determines trace moisture in petroleum products, lubricants, diesel fuel and oils using ASTM D6304 methods.
Moisture Determination in Aromatic Hydrocarbons | Karl Fischer
Learn how Karl Fischer titration accurately determines trace moisture in aromatic hydrocarbons including benzene, toluene, xylene and solvent blends.
Alcohols | Karl Fischer titrator AQ-300/MOICO-A19
H₂O ＋ I₂ ＋ SO₂ ＋ 3RN ＋ CH₃OH → 2RN・HI ＋ RN・HSO₄CH₃
2RN・HI → I₂ ＋ 2RN ＋ 2H⁺ ＋ 2e⁻
Alcohols do not interfere the Karl Fischer reaction and direct injection method could apply. Anode solution is selected in accordance with sample solubility. General-use anode solution contains methanol as solvent. Alcohols with long carbon chain have low solubility in methanol. In that case, use of anode solution for oil is appropriate.
When fritless cell is used, cathode solution is not necessary.
