Sample preparation: easy, safe and precise
The 860 KF Thermoprep is the new Metrohm instrument for thermal sample preparation in Karl Fischer titration (KF titration/KFT). It can be combined with a large number of KF titrators and KF coulometers for volumetric or coulometric water determinations.
Stumbling blocks in sample preparation and determination
Many substance, such as plastics or salts, release their water either very slowly or only at high temperatures. This means that they cannot be analyzed by direct volumetric or coulometric KF titration.
Certain samples are either sparingly soluble or not soluble at all in alcohols and therefore in Karl Fischer reagents containing alcohols. In order to bring such substances into solution, it is necessary to use harmful solubility promoters (such as chloroform, xylene...) or, alternatively, to perform complicated sample preparation steps.
If you place the sample directly in the titration vessel you rick contaminating the vessel. As a result, the titration vessel has to be cleaned more often and the reagents then also need to be replaced. This costs time and, because of the increased reagent consumption, also money. In addition, various substances present in the sample can undergo side-reactions with the KF reagents used and produce incorrect results.
Be on the safe side with thermal sample preparation
All the above problems can be avoided with the new 860 KF Thermoprep made by Metrohm. The sample is heated in a hermetically sealed vessel. The moisture released by the sample is transferred by a stream of dry carrier gas to the titration cell and determined there by Karl Fischer titration. Depending on the amount of water present, either a volumetric or coulometric titration is carried out. The sample itself does not enter the titration cell and therefore does not come into contact with the reagents used. This means that interfering side-reactions and matrix effects are excluded.
What benefits does the 860 KF Thermoprep offer you?
The most important benefits of the 860 KF Thermoprep are:
Easy operation
Safe procedur
Precise results
Easy operation
Well laid-out menu guidance makes working with the 860 KF Thermoprep a pleasure. All parameters can be set to your requirements by just pressing a few keys.
The sample preparation is also as easy as can be imagined. All you have to do is weigh out your sample into the sample vial and then set it hermetically.
Safe procedure
The extraordinarily stable and well thought-out construction of the 860 KF Thermoprep prevents the needle from being lowered beside the septum. You always hit the septum - with certainty.
Often the use of toxic solubility promoters can be avoided by using the oven method - harmful solvent vapours are a thing of the past.
Precise results
As the analytical conditions are identical for all samples, the results are reproducible and precise. The headspace vials are hermetically sealed by PTFE septum and thus guarantee a constant water content, even after the vials have been standing around for some time.
The heated transfer tubing prevents the condensation of water vapour and ensures that all the moisture enters the titration cell for determination.
The sample remains in the sample vessel and does not undergo any side-reactions with the KF reagents.
You will obtain your results in just a few steps:
1. Switch on the 860 KF Thermoprep and select the temperature
2. Place and empty conditioning vial in the oven and pierce it with the needle
3. Switch on the pump, adjust the gas flow and start the titrator (conditioning).
4. Weigh out the sample into a sample vial.
5. Hermetically seal the sample vial with the septum using the crimping tongs.
6. Wait until the preset temperature has been reached and «Conditioning OK» appears.
7. Start the titration at the titrator and carry out the following steps 8, 9 and 10 within six seconds.
8. Remove the conditioning vial from the oven using crimping tongs. Caution: hot!
9. Insert the sample vial into the oven of the 860 KF Thermoprep.
10. Pierce the septum with the needle and the wait until the titration has finished.
11. When the titration has finished, remove the sample vial from the oven using the crimping tongs. Caution: hot! Karl Fischer titration with Metrohm and the new 860 KF Thermoprep is easy, safe and precise.