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KF Coulometre
KF Coulometre

KF Coulometre

Å bestemme lavt fukt- og vanninnhold i prøver er ikke et problem for disse coulometrene.

Coulometrisk Karl Fischer-titrering er den ideelle metoden for å bestemme lavt fuktighets- og vanninnhold i prøver (0,001 til 1 % vann). Vårt utvalg av coulometre dekker alle krav og kan kombineres med KF-ovnsmetoden for vanskelige prøver.

  • Nøyaktig og pålitelig bestemmelse av vanninnhold på spornivå i området 0,001 til 1 %
  • Ulike coulometer versjoner tilgjengelig, for eksempel frittstående eller softwarestyrt
  • Vanskelige prøver kan enkelt analyseres med ovnsmetoden
  • Samsvar med FDA Regulation 21 CFR Part 11 og EudraLex, Volume 4, Annex 11

 

En rekke coulometre

Metrohm tilbyr ulike coulometre for å imøtekomme dine krav. Kontakt oss for å lære mer om våre coulometre.

Coulometer Egenskapet
Titrando coulometer
  • Software eller via touch-control 
  • I samsvar med (e.g., 21 CFR Part 11)
  • Automatisering og prøveprepareroningsalternativer
  • Automatisk prøveinjeksjon og titreringsstartgjenkjenning
Ti-Touch coulometer
  • Kompakt og frittstående coulometer
  • Alle komponenter integrert i ett kabinett
  • Touch-screen betjening, presise resultater og sikker håndtering
  • I samsvar med (21 CFR Part 11)
Eco Coulometer
  • Plassbesparende coulometer
  • Berøringsfølsom skjerm
  • Integrert magnetrører
OMNIS coulometer
  • High-end coulometric titrator for all your needs
  • Modular concept for maximum flexibility
  • Software control
  • Regulatory compliance (ie. 21 CFR part 11)
  • Automation and sample preparation options
  • Automatic sample injection and titration start recognition  

Brosjyre: OMNIS Coulometer and OMNIS Sample Robot Oven (8.000.5475, PDF, 2,8 MB)

Prøvepreparering og automatisering for coulometrisk KF-titrering

Metrohm Karl Fischer

For vanskelige prøver, for eksempel faste prøver eller prøver som ikke lett løses opp, kan du bruke KF-ovnsmetoden. I denne metoden varmes prøven i en ovn til vannet slippes ut, og vanndampen overføres til titreringsbeholderen for måling.

Vi tilbyr både manuelle ovner og automatiserte prøvevekslere med integrerte ovner for økt prøvegjennomstrømning.

Mer om prøvepreparering for KF

Hvorfor bruke coulometrisk KF-titrering for vanninnholdsbestemmelse?

En rekke standarder anbefaler coulometrisk Karl Fischer-titrering for bestemmelse av vanninnhold:

Standard Name
ASTM D890 Standard Test Method for Water in Liquid Pine Chemicals
ASTM D1123 Standard Test Method for Water in Engine Coolant Concentrate by the KF Reagent Method
ASTM D1533 Standard Test Method for Water in Insulating Liquids by Coulometric KF Titration
ASTM D3401 Standard Test Methods for Water in Halogenated Organic Solvents and Their Mixtures
ASTM D4928 Standard Test Method for Water in Crude Oils by Coulometric Karl Fischer Titration
ASTM D5460 Standard Test Method for Rubber Compounding Materials - Water in Rubber Additives
ASTM D6304 Standard Test Method for Determination of Water in Petroleum Products, Lubricating Oils, and Additives by Coulometric KF Titration
ASTM D7923 Standard Test Method for Water in Ethanol and Hydrocarbon Blends by Karl Fischer Titration
ASTM E1064 Standard Test Method for Water in Organic Liquids by Coulometric Karl Fischer Titratio
DIN EN ISO 12937 Petroleum products - Determination of water - Coulometric KF titration method
ISO 10337 Crude Petroleum - Determination of water - Coulometric KF titration method
UOP 481-10 Water in Liquid Hydrocarbons, and Heavy Hydrocarbons by Vaporizer, using Coulometric Titration
USP <921> Method 1c
EP 2.5.32 Water: Micro Determination

Hvilken KF titrator passer til dine behov?

Snakk med din Metrohm-representant og lær om den beste løsningen for dine behov!

Finn applikasjoner for KF Titrering

Coulometric Karl Fischer titrator – FAQs

What is coulometric Karl Fischer titration?

Coulometric titration is used to determine trace-levels of water in samples within a range of 10 µg to 200 mg water. However, larger amount of water (> 10 mg) require a lot of time and/or may exceed the water capacity of the KF reagent, which could lead to incorrect results.

The coulometric method uses electric current to generate the iodine that is needed for the Karl Fischer reaction. Metrohm KF Coulometers apply variable current strengths and pulse lengths, which allows precise "iodine addition" even in the region of the endpoint.

Learn more about coulometric KF titration in the application bulletin:

Coulometric water content determination according to Karl Fischer (AB-137, PDF, 228 KB)

Why is coulometric Karl Fischer titration used for water content determination?

Coulometric KF titration is a sensitive method suitable to determine low water contents between 0.001 and 1%. The coulometric method is an absolute method, meaning that there is no need for titer determination. In addition, a series of standards recommend coulometric Karl Fischer titration for water content determination:

Standard Name
ASTM D890 Standard Test Method for Water in Liquid Pine Chemicals
ASTM D1123 Standard Test Method for Water in Engine Coolant Concentrate by the KF Reagent Method
ASTM D1533 Standard Test Method for Water in Insulating Liquids by Coulometric KF Titration
ASTM D3401 Standard Test Methods for Water in Halogenated Organic Solvents and Their Mixtures
ASTM D4928 Standard Test Method for Water in Crude Oils by Coulometric Karl Fischer Titration
ASTM D5460 Standard Test Method for Rubber Compounding Materials - Water in Rubber Additives
ASTM D6304 Standard Test Method for Determination of Water in Petroleum Products, Lubricating Oils, and Additives by Coulometric KF Titration
ASTM D7923 Standard Test Method for Water in Ethanol and Hydrocarbon Blends by Karl Fischer Titration
ASTM E1064 Standard Test Method for Water in Organic Liquids by Coulometric Karl Fischer Titratio
DIN EN ISO 12937 Petroleum products - Determination of water - Coulometric KF titration method
ISO 10337 Crude Petroleum - Determination of water - Coulometric KF titration method
UOP 481-10 Water in Liquid Hydrocarbons, and Heavy Hydrocarbons by Vaporizer, using Coulometric Titration
USP <921> Method 1c
EP 2.5.32 Water: Micro Determination

What is the difference between coulometric and volumetric titration?

The main difference between coulometric and volumetric Karl Fischer titration concerns titrant addition. In volumetric Karl Fischer titration, the titrant is added directly to the sample with a buret. Coulometric Karl Fischer titration features a generator electrode, which electrochemically generates the required iodine for the titration directly in the titration cell.

Metrohm offers titrator solutions that perform volumetric or coulometric titration on separate titrators as well as both volumetric and coulometric titration in a single instrument. Contact us to learn more.

What are the requirements for coulometric titration?

Requirements for coulometric titrations are the following:

  • The process must take place with 100% current efficiency.
  • No side reactions must occur.
  • Oxidation or reduction must lead to a defined oxidation state.

Metrohm KF Coulometers meet these requirements with commercially available reagents.