Karl Fischer Reagents & Standards

Aquastar^® Karl Fischer reagents and standards ensure rapid, precise, and consistent results for water determination in solid, liquid, and gas samples. Our Aquastar^® product portfolio includes reagents for both volumetry and coulometry methods. Aquastar^® water standards are available as certified reference materials according to ISO 17034 for a precise titer determination, instrument check, and the verification of titration results.

Aquastar^® Reagents for Volumetric Karl Fischer Titration

The volumetric Karl Fischer titration method is used to determine water content by adding iodine containing titrant to the sample, which is then dissolved or dispersed in a suitable solvent. This method is recommended for higher water content (from 100 ppm to 100%) and promotes fast, precise, and reproducible results with high titration rates. We differentiate between one and two-component titration.

• One-component reagents – In a one-component titration method, all the reactive compounds such as iodine, base, sulfur dioxide, and the appropriate alcohol required for the Karl Fischer reaction are present in one reagent, the titrant. Aquastar^® CombiTitrants are available in different concentrations to determine higher and lower water contents. Aquastar^® CombiMethanol and Aquastar^® methanol-free CombiSolvent are solvents typically used with one component titrants. The one component titration is preferred for the titration of different sample matrices and for samples that require the addition of solubilizer.
• Two-component reagents – In a two-component system, the titrant is comprised of iodine and methanol, whereas sulfur dioxide and a base are dissolved in the solvent. Aquastar^® two-component titrants must be used along with Aquastar^® two-component solvent. The two-component Karl Fischer volumetric method shows improved buffer capacity, faster titration rates, and slightly better titer stability. They are often used for series from the same sample matrices or for acidic or alkaline samples.
• Reagents for Aldehyde and Ketones – Aquastar^® CombiTitrant 5 Keto and CombiSolvent Keto reagents are considered when performing Karl Fischer titration for water determination in ketones and aldehyde samples. These reagents are methanol-free to prevent side reactions and unreliable endpoints.
• Special reagents for oils and fats – Choose our Aquastar^® CombiSolvent Oil, CombiSolvent Fat, or Solvent Oils & Fats reagents for the determination of exact water contents in oils, fats, and long-chain hydrocarbons. Samples containing oils and fats (e.g. mineral oils, vegetable oils, fats, cremes, or ointments) must be completely dissolved or dispersed to determine the water content. Depending on the type of oil or fat, different solvents are needed to dissolve or extract the water completely from the sample for water determination.

Aquastar^® Coulometric Reagents

Coulometric Karl Fischer Titration is preferred for liquid samples with very low water content (10 ppm – 10.000 ppm). Our Aquastar range of coulometric Karl Fischer reagents is available for titration cells with and without a diaphragm. Our coulometric reagents CombiCoulomat frit, CombiCoulomat fritless, and Anolyte for coulometric Karl Fischer titration without diaphragm are free from chloroform for precise results. For your convenience, our combined CombiCoulomat frit and CombiCoulomat fritless reagents contain all reaction components in a single solution and can be used for both anode and cathode cells. We also offer special methanol-free reagents for aldehyde and ketone samples. Our Anolyte K and Catholyte K reagents are designed to determine exact water contents in aldehydes and ketones samples.

Aquastar^® Water Standards

The Aquastar^® portfolio contains a broad range of excellent water standards for titer determination, monitoring Karl Fischer equipment, and verifying measuring results. Our water standards are certified reference materials in accordance with ISO 17034 and measured using validated procedures in our DIN EN ISO/IEC 17025 accredited laboratory. To maintain transparency, we provide a batch-specific certificate of analysis for quality management (QM) documentation.

Smart Chemicals for Titration and Karl Fischer Titration

Our innovative Supelco^® titration technology enables a connection between SmartChemicals and the titrator. Our Aquastar^® Karl Fischer SmartTitrants and Aquastar^® SmartStandards transmit data wirelessly to the titrator. A brief touch on the SmartChemical RFID (Radio Frequency Identification) tag eliminates transmission errors, saves time, protects data, and increases efficiency.