GFS Chemicals Karl Fischer Reagents

Karl Fischer Reagents

GFS Chemicals manufactures the Watermark® Karl Fischer product line. We have one of the largest selections of Karl Fischer reagents in the industry, and the technical expertise to meet your project's needs. From volumetric and coulometric Karl Fischer reagents to certified water standards, we have the products you need in stock and ready to ship. GFS Chemicals also offers both pyridine and pyridine-free solutions. Our Watermark Karl Fischer coulometric reagents have a water capacity over 1000 mg/mL.

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Karl Fischer Product Categories

Volumetric titration is typically selected for samples in the 100 ppm to 100% water content range, although sample analysis down 10 ppm water is possible. One component Karl Fischer reagents are the most popular as they are the least expensive, and don't always require a special solvent. In one-component Karl Fischer Titration, a titrant with a known concentration is reacted with a sample in a vessel solvent, ultimately consuming the water in the sample.

The titrant contains all the components required for the KF reaction: iodine, base, sulfur dioxide, and a solvent medium. The vessel solvent is chosen to match the sample dissolution characteristics. By measuring the volume of the titrant added, the amount of water in the sample can be calculated. The Watermark product line includes reagents with titer values of 5 mg/mL, 2 mg/mL, and 1 mg/mL, covering an array of applications.

With a methanol-free and pyridine-free formula, Watermark volumetric titrants are suitable for all KF titration samples, even those with aldehydes or ketones.

Not sure which to choose?

Choose a
One-Component System if your lab is on a budget, or performs frequent KF titrations. All reactants are in the titrant bottle, and our Watermark non-hygroscopic titrants are designed to be exceptionally stable with a guaranteed shelf life of two years.

Choose a
Two-Component System if you need a higher degree of accuracy, faster titrations, or need to standardize less frequently. The lowest strength available is 0.5 mg/mL and is designed for applications with minimal sample, or very low water content.

Coulometric titration is typically selected with a water content of less than 1%, although samples with water content up to 5% are possible. Anolyte and catholyte choices are based on the sample matrix, which in turn influences generator choice.

Watermark reagents offer the best value and performance for Karl Fischer titration in the industry. With extended shelf life, rapid moisture determinations, and a stable end-point, it is evident that Watermark outperforms the competition. Watermark, by GFS Chemicals, is specially formulated to provide the ultimate in analytical performance.


Standardization of a Karl Fischer titrant is necessary to determine its water equivalency. GFS Chemicals manufactures a broad range of reference materials, including primary standards in our Columbus, Ohio facilities.

Water standards are delivered in boxes of 10 single-use ampoules, and come with a 5-year shelf life. Watermark water standards are methanol-free and can be used for all applications. All standards come with a Certificate of Analysis (COfA), are scrupulously tested in our ISO/IEC 17025 accredited management system, and are NIST traceable.

Solid standards, including sodium tartrate and potassium citrate, are also available.

The Karl Fischer reaction is pH dependent. Most of the Watermarks titrants and solvents are buffered to counter samples that cause small pH changes. If the sample causes the pH to change outside the required 5 to 7.5 range, side reactions and slow kinetics are likely to occur.

To counter the effects of samples with extremely high or low pH values, add a buffering material to adjust the pH back to the optimal pH range.

GFS Chemicals specializes in the manufacture of anhydrous magnesium perchlorate which is an excellent drying agent for air and gases. KF titration systems require protection from atmospheric moisture. We offer many options including molecular sieves, indicating silica beads, drierite and calcium-based desiccants.

Compare our prices and see if we can save you money over your current supplier.

Brand Item Description GFS Item Link
Quveon 81014 Water Standard 1.0 in MeOH 9425 Shop Now
Aquamicron GMW20 Standard Water/Methanol 9425 Shop Now
Aquamicron AWS02V Water Standard 0.2 5692 Shop Now
Hydranal 20618 Working Medium K 5322 Shop Now
Aqualine AL2300 Matrix K 5322 Shop Now
Hydra-Point 6275-68 KF Solvent Methanol Free 5322 Shop Now
Aquamicron KTX Solvent KTX 5322 Shop Now
Quveon 43503 Solvent KT 5322 Shop Now
Hydranal 34868 Coulomat Oil 5202 Shop Now
Quveon 17145 Coulometric AGR-OIL 5202 Shop Now
Hydranal 34741 Methanol, Dry 3569 Shop Now
Aquastar 188009 CombiMethanol 3569 Shop Now
Hydra-Point 6290-68 Methanol Anhydrous 3569 Shop Now
Aqualine AL2110 Solvent CM 2991 Shop Now
Hydranal 37855 Solvent CM 2991 Shop Now
Aquastar 188016 Solvent Oil 2991 Shop Now
Quveon 26541 Solvent CX 2991 Shop Now
Hydranal 37856 LipoSolver MH 2978 Shop Now
Aquastar 188016 Solvent for Oils and Fats 2978 Shop Now
Aquamicron OLX Solvent OLX 2978 Shop Now
Quveon 26541 Solvent CX 2978 Shop Now
Hydranal 34697 Solver (Crude Oil) 2978 Shop Now
Aquastar 188020 CombiSolvent Oils 2978 Shop Now
Aquamicron OL2 Solvent OLII 2978 Shop Now
Hydranal 34963 Potassium Citrate Standard 2385 Shop Now
Aqualine K2760 Potassium Citrate Standard 2385 Shop Now
Aquamicron SWS Solid Water Standard 2385 Shop Now
Hydranal 34841 Coulomat CG-K 2321 Shop Now
Aquastar 1697C-1 Coulomat C 2321 Shop Now
Hydra-Point 6286-00 Karl Fischer Coulometric Generator Solution (Universal Type) 2321 Shop Now
Aquamicron CXU Aquamicron CXU 2321 Shop Now
Hydranal 34813 Water Standard 5 2304 Shop Now
Hydranal 34849 Water Standard 10 2303 Shop Now
Aquastar 188052 Water Standard 1.0% 2303 Shop Now
Aquamicron AWS100V Water Standard 10 2303 Shop Now
Quveon 81037 Water Standard 10.0 2303 Shop Now
Hydranal 34828 Water Standard 1.0 2302 Shop Now
Aquastar 188051 Water Standard 0.1% 2302 Shop Now
Aquamicron AWS10V Water Standard 1.0 2302 Shop Now
Quveon 81024 Water Standard 1.0 2302 Shop Now
Hydranal 34847 Water Standard 0.1 2301 Shop Now
Aquastar 188050 Water Standard 0.01% 2301 Shop Now
Aquamicron AWS01V Water Standard 0.1 2301 Shop Now
Quveon 81014 Water Standard 0.1 2301 Shop Now
Hydranal 37864 Imidazole 1973 Shop Now
Aquastar 13709 Imidazole 1973 Shop Now
Hydranal 34816 Composite 5K 1893 Shop Now
Aquastar 188006 CombiTitrant 5K 1893 Shop Now
Aqualine AL-2720-80 Water Standard 10 1892 Shop Now
Aquamicron FLS FLS 1889 Shop Now
Hydranal 34739 AG-Oven 1889 Shop Now
Hydra-Point 6287-02 KF Coulometric Oven Reagent 1889 Shop Now
Quveon 18411 Coulometric AGR-Oven 1889 Shop Now
Hydranal 37817 Methanol Rapid 1885 Shop Now
Quveon 24275 Methanol Sharp 1885 Shop Now
Aqualine AL1900 Complete 1 1884 Shop Now
Hydranal 34827 Composite 1 1884 Shop Now
Aquastar 188001 CombiTitrant 1 1884 Shop Now
Quveon 23367 Composit 1T 1884 Shop Now
Hydranal 34836 Coulomat AG 1671 Shop Now
Hydranal 34810 Coulomat AD 1671 Shop Now
Aquamicron AXMI AXI 1671 Shop Now
Aquastar 188079 Anolyte 1671 Shop Now
Aquastar 109255 CombiCoulomat Frit 1671 Shop Now
Aquastar 109257 CombiCoulomat Fritless 1671 Shop Now
Aqualine AL2520500 Electrolyte AG 1671 Shop Now
Hydra-Point 6280-02 Karl Fischer Coulometric Vessel Solution (Pyridine-Free) 1671 Shop Now
Quveon 11008 Coulometric AGR 1671 Shop Now
Aqualine SK5 SK5 1621 Shop Now
Aquamicron GML Solvent ML 1621 Shop Now
Aqualine SK3 SK3 1620 Shop Now
Aquamicron GKS100M Titrant SS 1620 Shop Now
Hydranal 34820 Coulomat AK 1619 Shop Now
Aquamicron AKX AKX 1619 Shop Now
Aquastar AX1697E Coulomat AK 1619 Shop Now
Hydra-Point 6283-01 Coulometric Vessel Solution for Aldehydes and Ketones (Methanol-Free) 1619 Shop Now
Aqualine AL2710-40 Water Standard 1 1618 Shop Now
Aquastar 109259 Water Std. 5 mg/mL 1617 Shop Now
Aquamicron GCHP GCHP Check Solution P 1617 Shop Now
Aqualine AL2730-500 Water Standard 5 1617 Shop Now
Hydranal 34801 Titrant 5 1616 Shop Now
Aquastar 188010 Titrant 5 1616 Shop Now
Hydra-Point 6274-02 KF Titrant 5 mg/mL 1616 Shop Now
Quveon 22251 Titrant 5T 1616 Shop Now
Aqualine AL22001 Titrant 5 1616 Shop Now
Hydranal 34804 Buffer 1615 Shop Now
Aquastar 188035 Buffer 1615 Shop Now
Aqualine AL2350 Buffer 1615 Shop Now
Hydra-Point 6282-02 Buffer Solution 1615 Shop Now
Quveon 20756 Buffer Acid 1615 Shop Now
Hydranal 34840 Coulomat CG 1613 Shop Now
Quveon 13060 Coulometric CGR 1613 Shop Now
Aqualine AL2560 Electrolyte CG 1613 Shop Now
Hydra-Point 6281-00 Karl Fischer Coulometric Generator Solution (Pyridine-Free) 1613 Shop Now
Hydranal 34807 Coulomat A 1612 Shop Now
Aquastar AX1697A Coulomat A 1612 Shop Now
Hydra-Point 6280-02 Karl Fischer Coulometric Vessel Solution (Pyridine-Free) 1612 Shop Now
Aquamicron XAMA AX 1612 Shop Now
Aquamicron XAMA01 AX01 1612 Shop Now
Quveon 15572 Coulometric AGR-C 1612 Shop Now
Aqualine AL2500 Electrolyte A 1612 Shop Now
Aqualine AL2510 Electrolyte AD 1612 Shop Now
Hydranal 34800 Solvent 1610 Shop Now
Aquastar 188009 CombiMethanol 1610 Shop Now
Aquamicron GEX Solvent GEX 1610 Shop Now
Quveon 21114 Solvent 1610 Shop Now
Hydranal 34800 Solvent 1610 Shop Now
Aquastar 188015 CombiMethanol Solvent 1610 Shop Now
Hydra-Point 6276-68 General Purpose Solvent 1610 Shop Now
Aqualine AL21001 Solvent 1610 Shop Now
Hydranal 34738 Keto Solver 1609 Shop Now
Aquastar 188007 CombiSolvent Keto 1609 Shop Now
Hydra-Point 6275-68 KF Solvent Methanol Free 1609 Shop Now
Hydranal 34817 Working Medium K 1609 Shop Now
Hydra-Point 6275-68 KF Solvent Methanol Free 1609 Shop Now
Quveon 43503 Solvent KT 1609 Shop Now
Hydranal 34843 Coulomat AG-H 1607 Shop Now
Hydra-Point 6284-01 Karl Fischer Coulometric Vessel Solution (CFC-Free) 1607 Shop Now
Quveon 16138 AHR 1607 Shop Now
Aqualine K-2530 Electrolyte AG-H 1607 Shop Now
Aquamicron SAMA AS 1607 Shop Now
Hydranal 34811 Titrant 2 1603 Shop Now
Aquastar 188011 Titrant 2 1603 Shop Now
Quveon 25299 Titrant 2T 1603 Shop Now
Hydra-Point 6273-02 KF Titrant 2 mg/mL 1603 Shop Now
Hydranal 34806 Composite 2 1601 Shop Now
Aqualine AL1950 Complete 2 1601 Shop Now
Aquastar 188002 CombiTitrant 2 1601 Shop Now
Hydra-Point 6272-68 KF Reagent 2 mg/mL 1601 Shop Now
Aquamicron SSZ30L Titrant SS-Z 3 mg/ml 1601 Shop Now
Quveon 23336 Composit 2T 1601 Shop Now
Hydranal 34805 Composite 5 1600 Shop Now
Aquastar 188005 CombiTitrant 5 1600 Shop Now
Aqualine AL2200 Complete 5 1600 Shop Now
Hydra-Point 6271-68 KF Reagent 5 mg/ml 1600 Shop Now
Aquamicron SSZ50L Titrant SS-Z 5mg/ml 1600 Shop Now
Quveon 23268 Composit 5T 1600 Shop Now
Hydranal 34788 Humidity Absorber 963 Shop Now
Aquastar MX1583D Molecular sieve 3A 963 Shop Now
Hydranal 34803 Sodium Tartrate Dihydrate 805 Shop Now
Aquastar 106664 Sodium Tartrate Dihydrate 15.66% 805 Shop Now
Aqualine K2770 Sodium Tartrate Dihydrate 805 Shop Now
Hydranal 32035 Benzoic Acid 673 Shop Now
Aquastar BX0360 Benzoic Acid 673 Shop Now
Aqualine AC423475000 Benzoic Acid 673 Shop Now