The water content of many samples is difficult to determine because they are only slightly soluble in alcohols, contaminate the titration cell or undergo side reactions with the Karl Fischer reagents.
However, instead of introducing the sample into the oven by means of a sample boat, the vial technique is used, i.e. the sample is weighed directly into the sample vial, sealed and transferred to the oven. The 860 KF Thermoprep is a very compact instrument. Heating block, gas pump, flow meter and flow controller are all integrated, as are the drying flasks.
Features include:
• Strictly reproducible analysis conditions yield results with markedly improved precision
• Manual sample preparation is reduced to a minimum
• You achieve considerable time savings
• There is no contamination of the oven and the titration cell; consequently there are no carryover and memory effects
• The reagent consumption diminishes significantly as the titrant has to be exchanged only infrequently
• Water release from the sample improves as the carrier gas does not just pass over the sample but directly through it.
Advantages of this method:
• Direct determination without any sample preparation
• No side reactions
• Low detection limits
• Analysis time per sample: 3–5 min
• Temperature range: 50 – 250°C
• Flow control of air or N2
• Linked to volumetric or coulometric titrator for low to high level moisture determinations