Leírás
Használt METROHM 832 KF ThermPrep eladó!
The KF oven method
Many substances (e.g. plastics or inorganic salts) release their water only slowly or at high temperatures. Theyare therefore not suitable for a direct Karl Fischer titration. An additional problem is the low solubility of certain samples in alcohols. In these cases traditional methods recommend the use of toxic solvents to promote dissolution or alternatively extensive sample preparation procedures.
Moreover, if the sample is introduced directly into the titration cell the latter can be strongly contaminated, which means that it is necessary to exchange the titration solution and clean the cell frequently. Finally, there are various substances (e.g. ascorbic acid) that undergo side reactions with the KF reagents, thus falsifying the result.
By using the KF oven method the above-mentioned problems can be avoided. The substance under investigation is heated in a tube oven and the released water is transferred by a carrier gas to the titration cell where it is determined by Karl Fischer titration. As only the water enters the KF cell and the sample itself does not come into contact with the KF reagent, this means that unwanted side reactions and matrix effects are eliminated.